fix(prosemirror-markdown): escape literal <br> in text so it round-trips as text, not a hardBreak (#554)

A literal inline-HTML break tag typed as prose text (`<br>`, `<br/>`,
`<br />`) was emitted verbatim into markdown, so on re-import marked
parsed it as an inline-HTML line break and silently turned the user's
text into a hardBreak node, dropping the text. HTML-entity-encode only
the angle brackets of a break-tag sequence in `case "text"` so it lands
as `&lt;br&gt;` and the importer decodes it back to literal `<br>`.

Scoped strictly to the `<br…>` pattern (not every `<`/`>`), so stray
angle brackets in prose (`a < b > c`) are untouched, and to the
text-content path only — a real hardBreak serializes from its own case
(`  \n`, or `<br>` via inlineToHtml), so the serializer's own emitted
breaks are never escaped.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.env.example

@@ -124,6 +124,40 @@ MCP_DOCMOST_PASSWORD=
 # MCP_TOKEN=
 # MCP_SESSION_IDLE_MS=1800000
 #
+# --- MCP collaboration write path: concurrency + rights-staleness (#449) ------
+# MCP content writes (update_page, insert/replace nodes, comments-in-body, etc.)
+# go over the collaboration websocket and are serialized PER PAGE by an
+# in-process mutex (a module-level Map, one promise-chain per page UUID). This
+# guarantees no two MCP writes on the SAME page overlap and clobber each other.
+#
+# DEPLOY REQUIREMENT — SINGLE INSTANCE or STICKY SESSIONS. The mutex is
+# process-local. Behind a multi-replica load balancer WITHOUT sticky sessions,
+# two replicas can each "hold" the lock for the same page at the same time and
+# serialization is silently lost (concurrent full-document writes race on the
+# live Yjs fragment). Run the MCP/app as a SINGLE instance, OR pin a page's
+# traffic to one replica (sticky sessions / consistent hashing on page id). The
+# same constraint applies to the RAM-only stash_page blob store above. There is
+# deliberately no cross-process (e.g. Postgres advisory) lock yet — this is a
+# CONSCIOUS documented constraint, not an oversight (#449).
+#
+# To reduce connect-storms the write path caches ONE live collab session per
+# (wsUrl, page, token). Tunables (all optional; defaults are safe):
+# MCP_COLLAB_SESSION_IDLE_MS=60000     # idle TTL, reset per op; 0 disables cache
+# MCP_COLLAB_SESSION_MAX_ENTRIES=32    # LRU cap on cached sessions
+# MCP_COLLAB_TOKEN_TTL_MS=300000       # per-client collab-token cache (5 min)
+#
+# RIGHTS-STALENESS TRADE-OFF. A cached collab session writes under the token
+# captured at CONNECT time, and the collab-token cache reuses a token for its TTL.
+# So if a user's access to a page is REVOKED, MCP writes on an already-open
+# session may keep succeeding until the session ages out. MCP_COLLAB_SESSION_MAX_AGE_MS
+# is the HARD lifetime (checked at each acquire) that BOUNDS this window: after it,
+# the session is torn down and the next write re-auths with a fresh token, picking
+# up the revocation. Default 10 min. LOWER it to shorten the revocation lag at the
+# cost of more reconnects; RAISE it to reduce reconnects at the cost of a longer
+# stale-rights window. There is intentionally no push-based cache invalidation on
+# a rights change — this bounded window is the accepted trade-off (#449).
+# MCP_COLLAB_SESSION_MAX_AGE_MS=600000
+#
 # BLOB SANDBOX (stash_page). An in-RAM, process-local store that hands large page
 # content + images to an external consumer WITHOUT bloating the model context or
 # requiring Docmost auth. The stash_page tool serializes a page, mirrors its
@@ -191,17 +225,42 @@ MCP_DOCMOST_PASSWORD=
 
 # Silence timeout (ms) for EXTERNAL-MCP transport ONLY (not the chat provider).
 # Tighter than AI_STREAM_TIMEOUT_MS so a byte-silent/hung MCP server is broken in
-# ~1 min instead of 15. Note it also cuts a legitimately long but byte-silent
-# single tool call (a slow crawl that emits nothing until done) and an SSE
-# transport idling >1 min BETWEEN tool calls. Default 60000 (1 min).
+# ~1 min instead of 15. It cuts a legitimately long but byte-silent single tool
+# call (a slow crawl that emits nothing until done) on the HTTP (streamable)
+# transport, which opens a fresh request per call. The SSE transport — one
+# long-lived body across many calls — is NO LONGER governed by this timeout
+# (as of #489): its idle-BETWEEN-calls window has its own, raised bodyTimeout,
+# AI_MCP_SSE_BODY_TIMEOUT_MS below. Default 60000 (1 min).
 # AI_MCP_STREAM_TIMEOUT_MS=60000
 
+# bodyTimeout (ms) for the EXTERNAL-MCP SSE transport ONLY (#489). The SSE
+# transport holds ONE response body open across many tool calls, so undici's
+# bodyTimeout (time between body bytes) counts the LEGITIMATE silence BETWEEN the
+# model's tool calls, not just a hung single call. At the tight 1-min silence
+# timeout above, a normal >1-min gap between calls would break the SSE socket and
+# the cache would serve a dead client until TTL — so the SSE transport gets its
+# OWN, RAISED bodyTimeout. A single stuck call is still bounded by the per-call
+# cap (AI_MCP_CALL_TIMEOUT_MS), and a socket that does break is healed by the
+# in-run transport-error retry. The HTTP (streamable) transport keeps the tight
+# timeout. Default 600000 (10 min).
+# AI_MCP_SSE_BODY_TIMEOUT_MS=600000
+
 # Total wall-clock cap (ms) for ONE external MCP tool call (app-level, not
 # transport). Aborts a tool that keeps the socket warm (SSE heartbeats / trickle)
 # but never returns a result — which the silence timeout above never breaks.
 # Default 120000 (2 min).
 # AI_MCP_CALL_TIMEOUT_MS=120000
 
+# Kill-switch for the agent API-key feature (#501). Default ON when unset — a
+# deploy that never sets it must NOT silently kill every agent. STRICT parse:
+# only the literals `true` / `false` are accepted; a typo like `=0`/`=off`/`=False`
+# FAILS AT BOOT by design (never silently read as "enabled"), so the switch is
+# guaranteed to actually flip when an operator flips it during an incident. When
+# set to `false`: all api-key auth is DENIED (every api-key token is rejected) and
+# the api-key management endpoints return 404. The resolved state is logged at boot
+# (`API keys: ENABLED/DISABLED (API_KEYS_ENABLED=...)`) so it is verifiable per deploy.
+# API_KEYS_ENABLED=true
+
 # Max JSON/urlencoded request body size (bytes). Fastify's 1 MiB default is too
 # small for a long AI-chat research turn: the client resends the FULL message
 # history (every tool call + search result) on each turn, so a deep conversation's
@@ -217,6 +276,17 @@ MCP_DOCMOST_PASSWORD=
 # active" behavior.
 # AI_CHAT_DEFERRED_TOOLS=true
 
+# Final-step lockdown for the in-app agent loop (#444). Default OFF. When ON
+# (legacy), the LAST allowed step forces a text-only answer: the model's tools are
+# stripped (toolChoice=none) and a synthesis instruction is appended. That
+# tool-stripping caused a token-degeneration incident — robbed of its tools on the
+# final step mid-work, the model emitted a ~255KB block repeating a single token —
+# so the default is now OFF: the last step keeps its tools and gets only a SOFT
+# nudge to finish with a text summary, and a token-degeneration detector is the
+# universal anti-babble guard. Enable this ONLY for a model that reliably ends its
+# turns with a clear text answer.
+# AI_CHAT_FINAL_STEP_LOCKDOWN=false
+
 # --- Autonomous / detached agent runs (settings.ai.autonomousRuns) ---
 # Opt-in per workspace (AI settings; off by default). When on, a chat turn becomes
 # a server-side RUN that survives a browser disconnect — only an explicit Stop ends
@@ -242,6 +312,39 @@ MCP_DOCMOST_PASSWORD=
 # enabled for a workspace, and the same single-instance constraint applies (the
 # registry is process-local).
 # AI_CHAT_RESUMABLE_STREAM=false
+#
+# Per-run replay ring cap (#491), in BYTES, for the resumable-stream registry
+# above. The registry buffers the run's recent SSE tail so a reopened tab can
+# attach and continue from the step it already persisted; the ring is bounded and
+# rotates on every confirmed step-persist. This caps the un-persisted tail between
+# rotations — an overflow evicts the oldest frames and a late attach falls back to
+# 204 -> degraded poll, so correctness never depends on the size. Default 4194304
+# (4MB); a 0/invalid value falls back to the default. The per-subscriber backpressure
+# cap is derived as 2x this value. Only meaningful with AI_CHAT_RESUMABLE_STREAM on.
+# AI_CHAT_RUN_STREAM_MAX_BUFFER_BYTES=4194304
+
+# --- Run lifecycle tunables (#487) ---
+# These govern the universal run machinery (every turn is now a first-class run,
+# both modes) and rarely need changing.
+#
+# How long a server-side SUPERSEDE ("interrupt and send now") waits for the target
+# run to settle after issuing Stop before it degrades to a 409 SUPERSEDE_TIMEOUT
+# (nothing sent, the composer keeps the user's text). 10s is generous under a
+# healthy DB; do NOT raise it to paper over a slow DB — a SUPERSEDE_TIMEOUT is the
+# honest signal. Default 10000 (10s).
+# AI_CHAT_SUPERSEDE_TIMEOUT_MS=10000
+#
+# How often the periodic bidirectional reconcile job runs (heals runs/messages
+# left dangling by a crash or a lost terminal write). Default 120000 (2 min).
+# AI_CHAT_RECONCILE_INTERVAL_MS=120000
+#
+# Wall-clock cap for a SINGLE in-app tool call (a long paginated read, or a content
+# write whose collab commit hangs) — the per-call half of the composite abort
+# signal every in-app tool is wrapped with (the other half is the turn's Stop).
+# The reconcile staleness floor is derived as max(2 x this cap, 15min), so a very
+# high value delays stale-run recovery (the server boot-warns above 30min). Default
+# 120000 (2 min).
+# AI_CHAT_INAPP_TOOL_CALL_CAP_MS=120000
 
 # --- Anonymous public-share AI assistant ---
 # Opt-in per workspace (AI settings -> "public share assistant"; off by default).
@@ -290,6 +393,20 @@ MCP_DOCMOST_PASSWORD=
 #    VictoriaMetrics/Prometheus reaching it as <host>:<port>/metrics.
 # METRICS_PORT=9464
 #
+#    METRICS_BIND — interface the /metrics listener binds to. DEFAULT 127.0.0.1
+#    (loopback only), so the unauthenticated endpoint is NOT exposed on all
+#    interfaces. If the scraper runs in a SEPARATE container and reaches this as
+#    docmost:9464, set METRICS_BIND=0.0.0.0 — but then also set METRICS_TOKEN
+#    and/or keep the port on a private network, since /metrics is otherwise open.
+# METRICS_BIND=127.0.0.1
+#
+#    METRICS_TOKEN — optional Bearer token guarding /metrics. When set, every
+#    scrape MUST send `Authorization: Bearer <token>` (others get 401). Configure
+#    the scraper with the same bearer token (e.g. VictoriaMetrics/vmagent
+#    `bearer_token`, Prometheus `authorization.credentials`). Leave unset only
+#    when the endpoint is bound to loopback or an otherwise-trusted network.
+# METRICS_TOKEN=
+#
 # 2) CLIENT_TELEMETRY_ENABLED — the public client perf-telemetry sink.
 #    OFF by default. When true, the unauthenticated POST /api/telemetry/vitals
 #    endpoint is registered and browsers collect + send web-vitals / editor

.github/workflows/develop.yml

@@ -62,6 +62,38 @@ jobs:
     needs: [test, e2e-server, e2e-mcp, build]
     runs-on: ubuntu-latest
     timeout-minutes: 30
+    # Image boot-smoke (issue #476): every other job tests code from the working
+    # tree, but the :develop IMAGE that watchtower pulls was never actually
+    # started anywhere (incident classes #353/#452/#361-boot: startup-migrator
+    # crash-loop, runtime module missing from the image, wrong static-asset
+    # headers). The services below back a smoke boot of the exact image right
+    # before it is pushed; a smoke failure blocks the push.
+    services:
+      postgres:
+        # via mirror.gcr.io (Docker Hub pull-through cache; avoids Hub anonymous
+        # pull rate-limit that randomly fails on shared GitHub runner IPs).
+        image: mirror.gcr.io/pgvector/pgvector:pg18
+        env:
+          POSTGRES_DB: docmost
+          POSTGRES_USER: docmost
+          POSTGRES_PASSWORD: docmost
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd "pg_isready -U docmost"
+          --health-interval 5s
+          --health-timeout 5s
+          --health-retries 20
+      redis:
+        # via mirror.gcr.io (see postgres note above).
+        image: mirror.gcr.io/library/redis:7
+        ports:
+          - 6379:6379
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 5s
+          --health-timeout 5s
+          --health-retries 20
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -82,6 +114,37 @@ jobs:
         id: version
         run: echo "value=$(git describe --tags --always)" >> "$GITHUB_OUTPUT"
 
+      # Load the image into the local docker daemon so it can be booted (the
+      # push step below exports straight to the registry and leaves nothing
+      # runnable locally). CONVENTION: build-args here must stay TEXTUALLY
+      # IDENTICAL to the push step's build-args — same cache scope + same args
+      # means the layers are reused and the image we smoke IS the image we push.
+      - name: Build image for smoke (load, no push)
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          platforms: linux/amd64
+          build-args: |
+            APP_VERSION=${{ steps.version.outputs.value }}
+            AI_AGENT_ROLES_CATALOG_URL=https://raw.githubusercontent.com/vvzvlad/gitmost/develop/agent-roles-catalog
+          load: true
+          push: false
+          tags: gitmost:smoke
+          cache-from: type=gha,scope=develop-amd64
+
+      # Boot-smoke the exact image against the job services (see the comment on
+      # `services:` above): health (startup migrator), auth/setup, client dist
+      # served, immutable + brotli asset headers. Fails the job (and therefore
+      # the push) on any miss.
+      - name: Smoke the built image
+        run: bash scripts/ci/image-smoke.sh gitmost:smoke
+
+      # The smoke script leaves the container running on failure precisely so
+      # the boot error (migration mismatch, stack trace) is diagnosable here.
+      - name: Dump smoke container log on failure
+        if: failure()
+        run: docker logs gitmost-smoke 2>&1 | tail -200 || true
+
       - name: Build and push develop image
         uses: docker/build-push-action@v6
         with:
@@ -157,6 +220,19 @@ jobs:
       - name: Build prosemirror-markdown
         run: pnpm --filter @docmost/prosemirror-markdown build
 
+      # docmost-client.loader.ts type-imports from @docmost/mcp (issue #446); its
+      # build/ is gitignored and `test:e2e` type-checks, so build it here or tsc
+      # fails with TS2307 (mirrors the e2e-mcp / mcp-server-parity jobs).
+      - name: Build mcp
+        run: pnpm --filter @docmost/mcp build
+
+      # apps/server imports @docmost/token-estimate at runtime (history-budget.ts,
+      # #490); its dist/ is gitignored and `test:e2e` type-checks + runs the code,
+      # so build it here or tsc fails with TS2307 Cannot find module
+      # '@docmost/token-estimate' (mirrors the editor-ext / mcp build steps above).
+      - name: Build token-estimate
+        run: pnpm --filter @docmost/token-estimate build
+
       - name: Run migrations
         run: pnpm --filter ./apps/server migration:latest
 

.github/workflows/nightly-property.yml

@@ -124,9 +124,17 @@ jobs:
           exit "$FAILED"
 
       # A GENUINE counterexample: fast-check printed a shrunk minimal case and its
-      # reproducing seed into property-output.txt. File a dedup-guarded issue whose
-      # title prefix is UNIQUE to counterexamples, so an infra failure (handled by
-      # the next step under a different title) can never poison this dedup.
+      # reproducing seed into property-output.txt. File a dedup-guarded issue.
+      #
+      # Dedup is keyed on a HASH of the SHRUNK COUNTEREXAMPLE (the minimal failing
+      # input), NOT on the issue title prefix. Keying on the prefix would let a
+      # single open issue swallow every OTHER counterexample (a different bug B whose
+      # title shares the prefix would be treated as a duplicate and stay silent until
+      # the first issue is closed). Hashing the shrunk example instead means two
+      # DIFFERENT counterexamples get two DIFFERENT issues, while a re-find of the
+      # SAME counterexample still dedupes onto the existing one. The infra-failure
+      # step (below) still keys on its own distinct title, so it can never poison
+      # this dedup either.
       - name: File counterexample issue
         # always() is REQUIRED: the fuzz step exits nonzero on a failing shard,
         # so a bare `if:` (implicitly success() && ...) would skip this step
@@ -146,25 +154,48 @@ jobs:
             echo "No fast-check counterexample signature — infra failure, handled by the next step."
             exit 0
           fi
-          TITLE="${TITLE_PREFIX} (seed=${FAIL_SEED})"
+          # Extract the SHRUNK counterexample block: the "Counterexample:" line(s)
+          # up to (but excluding) the "Shrunk N time(s)" / "Got error" line. This is
+          # the minimal failing INPUT and is STABLE across the different seeds/paths
+          # that reach the same bug — unlike the seed, path, or shrink count (which
+          # precede/follow this block and vary run-to-run) and unlike the whole
+          # output (which embeds those varying parts). Hashing THIS is what makes the
+          # dedup identity the bug itself rather than an incidental run detail.
+          CE_TEXT=$(awk '/Counterexample:/{c=1} /Shrunk [0-9]+ time|Got error/{c=0} c{print}' property-output.txt)
+          if [ -z "$CE_TEXT" ]; then
+            # No parseable shrunk block (unexpected — the signature check above
+            # already confirmed fast-check output). Fall back to the reproducing
+            # seed so we still emit a stable identity instead of silently deduping.
+            CE_TEXT="seed:${FAIL_SEED}"
+          fi
+          # Stable short id: first 12 hex chars of sha256 over the counterexample.
+          CE_HASH=$(printf '%s' "$CE_TEXT" | sha256sum | cut -c1-12)
+          # Machine-readable marker embedded in the issue body; the open-issue search
+          # below matches on it (and on the hash in the title) so identity travels
+          # with the issue regardless of any human title edits.
+          CE_MARKER="<!-- counterexample-hash: ${CE_HASH} -->"
+          export CE_HASH CE_MARKER
+          TITLE="${TITLE_PREFIX} [${CE_HASH}] (seed=${FAIL_SEED})"
 
-          # Best-effort dedup: skip if an open issue with the counterexample title
-          # prefix already exists. A failure of this check must NOT block creation.
+          # Dedup on the counterexample hash: skip only if an OPEN issue already
+          # carries this exact hash (in its title or its body marker). A different
+          # counterexample has a different hash and is NOT deduped. A failure of this
+          # check must NOT block creation.
           EXISTING=""
           if EXISTING=$(curl -sS \
               -H "Authorization: token ${GITHUB_TOKEN}" \
               "${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}/issues?state=open&limit=100"); then
             if printf '%s' "$EXISTING" \
-                | node -e 'let s="";process.stdin.on("data",d=>s+=d).on("end",()=>{let a;try{a=JSON.parse(s)}catch{process.exit(1)}if(!Array.isArray(a))process.exit(1);const p=process.env.TITLE_PREFIX;process.exit(a.some(i=>typeof i.title==="string"&&i.title.startsWith(p))?0:1)})'; then
-              echo "An open '${TITLE_PREFIX}' issue already exists — skipping creation."
+                | node -e 'let s="";process.stdin.on("data",d=>s+=d).on("end",()=>{let a;try{a=JSON.parse(s)}catch{process.exit(1)}if(!Array.isArray(a))process.exit(1);const h=process.env.CE_HASH,m=process.env.CE_MARKER;process.exit(a.some(i=>(typeof i.title==="string"&&i.title.includes(h))||(typeof i.body==="string"&&i.body.includes(m)))?0:1)})'; then
+              echo "An open issue for counterexample ${CE_HASH} already exists — skipping creation."
               exit 0
             fi
           fi
 
           # Build the JSON body with the test output SAFELY escaped (never hand-
           # interpolate the counterexample into JSON).
-          BODY_TEXT=$(printf 'A nightly property fuzz SHARD failed with a fast-check counterexample.\n\n- failing shard seed: `%s`\n- NUM_RUNS (per shard): `%s`\n- run: %s\n\nReproduce locally:\n\n```\nPROPERTY_SEED=%s PROPERTY_NUM_RUNS=%s pnpm --filter @docmost/prosemirror-markdown exec vitest run test/generative/\n```\n\nfast-check shrinks the failure to a minimal counterexample. Commit it as a permanent fixture under `packages/prosemirror-markdown/test/fixtures/counterexamples/` + a case in `counterexamples.test.ts`, then FIX the converter (do not weaken a property). See `packages/prosemirror-markdown/README.md`.\n\nTail of the test output (contains the shrunk counterexample):\n\n```\n%s\n```\n' \
-            "$FAIL_SEED" "$NUM_RUNS" "$RUN_URL" "$FAIL_SEED" "$NUM_RUNS" "$(tail -n 120 property-output.txt)")
+          BODY_TEXT=$(printf 'A nightly property fuzz SHARD failed with a fast-check counterexample.\n\n- counterexample hash: `%s`\n- failing shard seed: `%s`\n- NUM_RUNS (per shard): `%s`\n- run: %s\n\nReproduce locally:\n\n```\nPROPERTY_SEED=%s PROPERTY_NUM_RUNS=%s pnpm --filter @docmost/prosemirror-markdown exec vitest run test/generative/\n```\n\nfast-check shrinks the failure to a minimal counterexample. Commit it as a permanent fixture under `packages/prosemirror-markdown/test/fixtures/counterexamples/` + a case in `counterexamples.test.ts`, then FIX the converter (do not weaken a property). See `packages/prosemirror-markdown/README.md`.\n\nTail of the test output (contains the shrunk counterexample):\n\n```\n%s\n```\n\n%s\n' \
+            "$CE_HASH" "$FAIL_SEED" "$NUM_RUNS" "$RUN_URL" "$FAIL_SEED" "$NUM_RUNS" "$(tail -n 120 property-output.txt)" "$CE_MARKER")
 
           jq -n --arg title "$TITLE" --arg body "$BODY_TEXT" \
             '{title: $title, body: $body}' > payload.json

.github/workflows/test.yml

@@ -1,5 +1,13 @@
 name: Test
 
+# NO `paths:` filter on purpose (issue #447). The tool-spec REGISTRY is split
+# across two packages that MUST stay in sync: the specs live in `packages/mcp`
+# but the parity/tier guard tests that read them live in the `apps/server` jest
+# suite. A PR touching only `packages/mcp/**` must therefore still run the SERVER
+# suite (and vice-versa), or an in-app wiring break slips through green and only
+# surfaces on develop after merge. The `test` job below runs BOTH suites via
+# `pnpm -r test` on every PR; the dedicated `mcp-server-parity` job makes that
+# cross-package gate explicit and fast. Do not add a `paths:` filter here.
 on:
   pull_request:
   workflow_call:
@@ -17,37 +25,65 @@ jobs:
   # filename sorts BEFORE migrations already applied on the target branch (and
   # thus in prod). The Kysely startup migrator rejects that as "corrupted
   # migrations" and crash-loops the app on boot (incident #361). This gate fails
-  # the PR so the migration is renamed to a current timestamp before merge. Only
-  # runs for pull_request events (needs a base branch to diff against).
+  # the PR so the migration is renamed to a current timestamp before merge.
+  # Runs for pull_request (diff against the base branch) AND for push (#476
+  # retrospective: a DIRECT push to develop used to bypass this PR-only gate
+  # entirely — now the push is diffed against its `before` SHA; workflow_call
+  # from develop.yml inherits the caller's push event). workflow_dispatch has
+  # nothing to diff against and still skips the job.
   migration-order:
-    if: github.event_name == 'pull_request'
+    if: github.event_name == 'pull_request' || github.event_name == 'push'
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - name: Checkout (full history for the base-branch diff)
+      - name: Checkout (full history for the base diff)
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - name: Added migrations must sort after the newest on the base branch
+      - name: Added migrations must sort after the newest on the base
         env:
           TARGET_BRANCH: ${{ github.base_ref }}
+          BEFORE_SHA: ${{ github.event.before }}
         run: |
           set -euo pipefail
           MIG_DIR="apps/server/src/database/migrations"
-          # checkout above already did fetch-depth:0 (full history). Fetch the base
-          # WITHOUT --depth (a shallow graft would truncate the base history and
-          # break the merge-base when the base has moved ahead of the PR merge —
-          # exactly the long-branch-vs-moving-base case this gate guards, #361).
-          git fetch --no-tags origin "$TARGET_BRANCH"
-          newest_on_target=$(git ls-tree -r --name-only "origin/${TARGET_BRANCH}" "$MIG_DIR" | sort | tail -1)
+          if [ "${GITHUB_EVENT_NAME}" = "pull_request" ]; then
+            # checkout above already did fetch-depth:0 (full history). Fetch the base
+            # WITHOUT --depth (a shallow graft would truncate the base history and
+            # break the merge-base when the base has moved ahead of the PR merge —
+            # exactly the long-branch-vs-moving-base case this gate guards, #361).
+            git fetch --no-tags origin "$TARGET_BRANCH"
+            BASE="origin/${TARGET_BRANCH}"
+          else
+            # push event: compare against the pre-push tip of the branch.
+            if [ "$BEFORE_SHA" = "0000000000000000000000000000000000000000" ]; then
+              echo "::notice::branch creation push — nothing to compare"
+              exit 0
+            fi
+            if ! git cat-file -e "${BEFORE_SHA}^{commit}" 2>/dev/null; then
+              # The before-SHA is not in the clone (a force-push rewrote history).
+              # One recovery attempt — refresh every remote head (cheap: the
+              # checkout is already fetch-depth:0); a fetch failure aborts via
+              # `set -e`, which is fail-closed too.
+              git fetch --no-tags origin '+refs/heads/*:refs/remotes/origin/*'
+            fi
+            if ! git cat-file -e "${BEFORE_SHA}^{commit}" 2>/dev/null; then
+              # FAIL-CLOSED: without the before-SHA there is no base to prove the
+              # ordering against, and a gate whose job is to BLOCK must not guess.
+              echo "::error::force-push detected — verify migration order manually, then re-run via workflow_dispatch"
+              exit 1
+            fi
+            BASE="$BEFORE_SHA"
+          fi
+          newest_on_target=$(git ls-tree -r --name-only "$BASE" "$MIG_DIR" | sort | tail -1)
           # NO `|| true`: a diff failure (e.g. an unresolved merge-base) must fail
           # the job CLOSED — a gate whose job is to BLOCK must never pass on error.
           # `set -e` above already aborts on a non-zero diff exit.
-          added=$(git diff --diff-filter=A --name-only "origin/${TARGET_BRANCH}...HEAD" -- "$MIG_DIR")
+          added=$(git diff --diff-filter=A --name-only "${BASE}...HEAD" -- "$MIG_DIR")
           bad=0
           for f in $added; do
             if [[ "$f" < "$newest_on_target" || "$f" == "$newest_on_target" ]]; then
-              echo "::error::Migration $f sorts at or before the newest on ${TARGET_BRANCH} ($newest_on_target) — rename it with a CURRENT timestamp before merge (do not change its contents). See incident #361."
+              echo "::error::Migration $f sorts at or before the newest on the base ($newest_on_target) — rename it with a CURRENT timestamp before merge (do not change its contents). See incident #361."
               bad=1
             fi
           done
@@ -123,6 +159,14 @@ jobs:
       - name: Build prosemirror-markdown
         run: pnpm --filter @docmost/prosemirror-markdown build
 
+      # @docmost/token-estimate is a shared workspace package the client vitest
+      # suite resolves via its dist build (main: ./dist/index.js); dist/ is
+      # gitignored and `pnpm -r test` does NOT honour nx `dependsOn: ^build`, so
+      # build it before the recursive test run or the client suite fails with
+      # "Failed to resolve import '@docmost/token-estimate'" (#490).
+      - name: Build token-estimate
+        run: pnpm --filter @docmost/token-estimate build
+
       - name: Run unit tests
         run: pnpm -r test
 
@@ -132,3 +176,53 @@ jobs:
       # isolated `docmost_test` DB and migrates it to latest.
       - name: Run server integration tests
         run: pnpm --filter server test:int
+
+  # Cross-package tool-spec parity gate (issue #447). The tool-spec registry lives
+  # in `packages/mcp` but its parity/tier guard tests live in the `apps/server`
+  # jest suite, so a PR touching ONLY one of the two packages must still run BOTH
+  # sides — otherwise an in-app wiring break (e.g. PR #434 drawio) passes the mcp
+  # suite green and only surfaces on develop after merge. The `test` job already
+  # runs everything via `pnpm -r test`; this job is a fast, explicitly-named guard
+  # that runs the mcp `node --test` suite AND the server tool-guard jest specs
+  # together, so the coupling is visible and can never be accidentally split by a
+  # path filter. No Postgres/Redis needed: these specs mock the DB/loader.
+  mcp-server-parity:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      # Shared deps first (build/ dirs are gitignored; see test.yml build order).
+      - name: Build editor-ext
+        run: pnpm --filter @docmost/editor-ext build
+
+      - name: Build prosemirror-markdown
+        run: pnpm --filter @docmost/prosemirror-markdown build
+
+      # Build the mcp package so build/ carries a FRESH REGISTRY_STAMP (#447): the
+      # build runs gen-registry-stamp.mjs before tsc, so a build/ vs src/ skew
+      # cannot slip into the tests that exercise the loader's stale-check.
+      - name: Build mcp (regenerates REGISTRY_STAMP)
+        run: pnpm --filter @docmost/mcp build
+
+      # mcp side: the standalone MCP server's own tool-spec / instructions guards.
+      - name: Run mcp tool-spec suite
+        run: pnpm --filter @docmost/mcp test
+
+      # server side: the parity + tier guards that read packages/mcp/src/tool-specs
+      # and assert the in-app AI-chat wiring matches it.
+      - name: Run server tool-spec guard specs
+        run: pnpm --filter server exec jest shared-tool-specs.contract tool-tiers ai-chat-tools.service --runInBand

.gitignore

@@ -2,6 +2,11 @@
 .env.dev
 .env.prod
 data
+# Exception: the committed draw.io shape catalog (issue #424) lives in a `data/`
+# dir, but the bare `data` ignore above is meant for runtime state, not this
+# bundled build asset. Re-include the directory and its contents.
+!packages/mcp/data/
+!packages/mcp/data/**
 # compiled output
 /dist
 node_modules
@@ -19,6 +24,15 @@ packages/prosemirror-markdown/build/
 # markdown convention; the package is private and rebuilt at deploy.
 packages/mcp/build/
 
+# mcp REGISTRY_STAMP codegen output (issue #447). Regenerated into src/ by
+# scripts/gen-registry-stamp.mjs on every `build`/`pretest` (before tsc), so it
+# is a build artifact like build/ — never committed, always fresh.
+packages/mcp/src/registry-stamp.generated.ts
+
+# token-estimate compiled output (#490; built in CI/Docker via `pnpm build` /
+# the server `pretest`, never committed, so src/ and prod can never diverge).
+packages/token-estimate/dist/
+
 # Logs
 logs
 *.log

AGENTS.md

@@ -5,6 +5,139 @@ repository. It has two layers: **how to run a task end-to-end** (the
 sections below), and **how the codebase is built** (the technical sections
 further down, formerly in `CLAUDE.md`).
 
+## ARCHITECTURAL INVARIANTS — NON-NEGOTIABLE
+
+THE TEN RULES BELOW ARE HARD CONSTRAINTS. Each one was paid for with a real
+production incident or a multi-PR bug chain in THIS repository (cited inline).
+They override convenience, deadlines and "it's just a small feature". A PR that
+violates any of them MUST be rejected in review regardless of how good the rest
+of it is. If a task genuinely seems to require breaking one — STOP and raise it
+with the owner; do not code around it.
+
+### 1. EVERY BUFFER, CACHE, HISTORY AND PAYLOAD HAS AN EXPLICIT SIZE BUDGET
+
+Nothing accumulates unboundedly. A row/item cap is NOT a byte cap. Anything
+replayed to a model, buffered in memory, persisted per step, or refetched by a
+poll must state its budget in bytes/tokens and enforce it. Rewriting a growing
+structure in full on every increment is FORBIDDEN — append or diff instead;
+O(n²) write/serialize patterns do not pass review.
+(Paid for by: full-row rewrite on every agent step — hundreds of MB of Postgres
+writes per 50-step run, with every tool output serialized twice; unbounded
+history replay killing long chats on the provider context window; 32 MB replay
+buffers per active run.)
+
+### 2. EVERYTHING LONG-RUNNING TERMINATES BY CONSTRUCTION
+
+Every run / row / session / lease / subscriber / queue entry must define AT
+DESIGN TIME: its owner; every terminal state; who writes the terminal state on
+EVERY path (success, error, abort, disconnect in each phase, process restart);
+retries for the terminal write; and a periodic sweeper that does not depend on
+a reboot. A best-effort terminal write with no retry and no sweep is FORBIDDEN.
+(Paid for by: assistant rows stuck 'streaming' forever; runs stuck 'running'
+409-locking their chat until a restart — the #183/#184 follow-up chain.)
+
+### 3. EVERY AWAIT IS CANCELLABLE AND DEADLINED; NEVER BLOCK THE EVENT LOOP
+
+Every async step inside a request or agent turn honors the turn's AbortSignal
+AND a wall-clock deadline — including in-app tools, lock queues and pagination
+loops, not just external calls. Synchronous CPU work beyond ~50 ms goes to a
+worker_thread. Promise.race DOES NOT cancel synchronous work — using it as a
+"timeout" for sync computation is forbidden (the timer only fires after the
+event loop is free again, i.e. after the damage is done).
+(Paid for by: in-app tools ignoring abortSignal and writing pages AFTER Stop;
+the synchronous ELK layout freezing every SSE stream in the process; the
+step-0 MCP handshake hang — #397.)
+
+### 4. ONE SOURCE OF TRUTH; EVERYTHING ELSE IS A REBUILDABLE CACHE
+
+Postgres is the authoritative state. Every in-memory structure (registries,
+caches, client stores) must be reconstructible from the DB and treated as
+lossy. The client renders SERVER-DECLARED state — "a run is active" is a server
+fact delivered as data, never inferred from side signals (204 vs 2xx, the
+flavor of a disconnect). A new feature must name the owner of each piece of
+state before implementation starts.
+(Paid for by: the strip/restore resume machinery, silently frozen UIs and
+ghost sends after unmount — the #381→#432→#456 chain.)
+
+### 5. STATE MACHINES ARE EXPLICIT — ONE-SHOT FLAGS ARE FORBIDDEN
+
+A complex lifecycle (chat thread, resume/reconnect, run) lives in a named-state
+automaton (reducer / enum) where every state has an owner and a rendered
+representation — including the failure states. Adding a boolean ref that one
+callback arms and another reads-and-clears is FORBIDDEN in the AI-chat client.
+New behavior = a new named state + explicit transitions, and the interruption
+matrix (disconnect in each phase × restart × stop × supersede) is enumerated at
+design time, not discovered one incident at a time.
+(Paid for by: 26 one-shot useRef flags in chat-thread.tsx and the drip of
+"one more missing transition" across #381→#386/#389→#432→#456.)
+
+### 6. NO NEW MODE FORKS; A FLAG IS FOR ROLLOUT, THEN IT DIES
+
+A behavior flag that forks a code path must ship with a written sunset
+condition; stacking a new flag onto the existing matrix without deleting or
+scheduling an old one is forbidden. While a temporary fork exists, BOTH sides
+must share identical lifecycle handling (abort semantics, error listeners,
+concurrency gates) — asymmetric forks are outlawed.
+(Paid for by: legacy vs autonomous divergence — the one-active-run gate and
+the socket 'error' listener each existing on only ONE side; 2^4 flag
+combinations each with different abort semantics.)
+
+### 7. NO HAND-SYNCED MIRRORS — CODEGEN OR A CI PARITY TEST, NOTHING LESS
+
+Two copies of the same knowledge (schema, tool registry, glyph map, probe
+body, hash/normalize algorithm, label list) require either generation from a
+single source or a CI test that FAILS on drift. A "mirror this change over
+there" comment is NOT a guard and does not pass review.
+(Paid for by: #293 — three drifting converter copies losing data; #447 —
+REGISTRY_STAMP covering only one of the mirrored files; ~10 still-unguarded
+mirrors across the MCP layer.)
+
+### 8. CACHES, HEADERS, BUFFERS AND FSM TRANSITIONS GET AN INTEGRATION TEST OF THE OBSERVABLE PROPERTY
+
+A unit test of a pure helper DOES NOT COUNT for these. Test the real header on
+the real HTTP response, the real cache hit under real token sources, the real
+transition under a really-killed socket. If the observable property cannot be
+tested, the design is wrong — fix the design, not the test.
+(Paid for by: #431→#439 — a cache keyed on a fresh-per-call JWT, so it NEVER
+hit and became prod incident #435 while its unit tests stayed green; and by
+the #352→#455 immutable-cache header silently overwritten by a framework
+default AFTER the unit-tested code ran.)
+
+### 9. CLIENT INPUT IS HOSTILE UNTIL VALIDATED — ALSO BEFORE PERSISTENCE
+
+Anything from the browser (message parts, ids, titles, selections, flags) is
+validated/sanitized BEFORE it is persisted into a row that will later be
+replayed into a prompt, a converter or another subsystem. A poisoned row must
+never be able to permanently brick a chat or a page on every subsequent read.
+(Paid for by: unvalidated UIMessage parts persisted verbatim — one bad row
+500s the chat on every later turn; #159 client-spoofed page titles; #388
+selection re-sanitized server-side for the same reason.)
+
+### 10. FAILURES ARE LOUD AND SPECIFIC; SILENT DEGRADATION IS FORBIDDEN
+
+Extends the error convention below: a fire-and-forget write is allowed ONLY
+with a metric or a greppable ERROR log; a degraded mode (dead cached MCP
+client, stopped poll, exhausted retries, evicted buffer) must be VISIBLE to
+the user or the operator. A feature that can quietly stop working — a frozen
+"streaming…" UI, a poll that silently gives up, a cache serving corpses — does
+not pass review.
+(Paid for by: the degraded poll's silent 10-minute death leaving a forever-
+"streaming" answer; dead MCP clients served from cache while every external
+tool call failed; #435 being caught in minutes ONLY because metrics — #403 —
+existed.)
+
+## Default skill for feature design
+
+For any feature-design request — the user hands over a raw feature idea, asks
+to design or think through a feature, or to draft an issue («спроектируй»,
+«продумай фичу», «составь ишью», "design X", "write an issue for X") — invoke
+the `orchestrator-feature-designer` skill (Skill tool) BEFORE any other work.
+It is the default operating mode for design work in this repository: research
+→ design checklist (R1–R10) → forks resolved with the human → adversarial
+self-attack → filed PR-sized issues. Do not design features or write issues
+ad-hoc while this skill is available. This does not apply to non-design work
+(bug fixes, reviews, retrospectives, refactors already specified by an issue).
+
 ## Task lifecycle
 
 ### 1. Start: sync with develop
@@ -201,7 +334,7 @@ pnpm workspace (`pnpm@10.4.0`) orchestrated by **Nx**. Four workspace packages:
 | `apps/client` | `client` | React 18 + Vite + Mantine 8 + TanStack Query + Jotai | SPA frontend |
 | `packages/editor-ext` | `@docmost/editor-ext` | Tiptap/ProseMirror | Shared Tiptap node/mark extensions, imported by both the client and the server |
 | `packages/mcp` | `@docmost/mcp` | MCP SDK, Tiptap, Yjs | Standalone MCP server, also bundled into the server at `/mcp`. Consumes the shared converter/schema from `@docmost/prosemirror-markdown` (#293) — it no longer carries its own vendored converter/schema copy |
-| `packages/prosemirror-markdown` | `@docmost/prosemirror-markdown` | Tiptap, marked, jsdom | The single, canonical ProseMirror↔Markdown converter + Docmost schema mirror (#293). Consumed by `mcp`, `git-sync`, AND `apps/server` (server-side markdown import/export, #345); there is exactly ONE copy of the converter now |
+| `packages/prosemirror-markdown` | `@docmost/prosemirror-markdown` | Tiptap, marked; jsdom (Node only) | The single, canonical ProseMirror↔Markdown converter + Docmost schema mirror (#293). Consumed by `mcp`, `git-sync`, `apps/server` (server-side markdown import/export, #345), AND `apps/client` (markdown paste/copy + AI-chat render, via the `browser` entry — native `DOMParser`, no jsdom in the client bundle, #347); there is exactly ONE copy of the converter now |
 
 `build` targets are Nx-cached and dependency-ordered (`dependsOn: ["^build"]`), so `editor-ext` builds before the apps. `nx.json` sets `affected.defaultBase: main`.
 
@@ -248,6 +381,22 @@ pnpm collab:dev              # run the collaboration server process standalone (
 > that order). Reach for it whenever you run a consumer package's checks on their
 > own rather than through the full `pnpm build`.
 
+> **Editing an MCP tool spec requires a rebuild (issue #447).** The running
+> server loads the **compiled** `packages/mcp/build/` of `@docmost/mcp` (via the
+> runtime loader in `apps/server/src/core/ai-chat/tools/docmost-client.loader.ts`),
+> but the parity/tier guard tests read `packages/mcp/src/tool-specs.ts`. So if you
+> edit `tool-specs.ts` (any tool name, description, tier, catalog line, or input
+> schema) **without rebuilding**, `build/` and `src/` silently diverge — the tests
+> stay green while the server serves the OLD tools. To close that gap, the build
+> emits a `REGISTRY_STAMP` (a deterministic hash of the tool-specs content, via
+> `scripts/gen-registry-stamp.mjs` before `tsc`); on dev/test startup the loader
+> recomputes it from `src/` and **refuses to start with a "@docmost/mcp build is
+> stale …" error** on a mismatch (a pure no-op in prod, where only `build/` ships).
+> After editing tool specs, rebuild:
+> ```bash
+> pnpm --filter @docmost/mcp build     # or: pnpm --filter @docmost/mcp watch
+> ```
+
 **Lint** (per package — there is no root lint script):
 ```bash
 pnpm --filter server lint    # eslint --fix on server .ts
@@ -306,14 +455,15 @@ The API server is a Fastify app with a global `/api` prefix (`main.ts` excludes
    - `core/ai-chat/tools/` — the agent's ~40 read+write tools. Every tool runs under the **calling user's** CASL permissions via a per-user loopback access token (`docmost-client.loader.ts`), so the agent can never exceed what the user could do. Only **reversible** operations are exposed (page history + trash; no permanent delete). Agent edits get an "AI agent" provenance badge in page history (`20260616T130000-agent-provenance` migration).
    - `core/ai-chat/embedding/` — RAG indexer + a BullMQ consumer on `AI_QUEUE` that embeds pages into `page_embeddings` (vector search), complementing Postgres full-text search. Pages are (re)indexed on edit; `AI_EMBEDDING_TIMEOUT_MS` bounds a hung embeddings endpoint.
    - `core/ai-chat/external-mcp/` — admins can attach external MCP servers (e.g. Tavily) to give the agent web access. **`ssrf-guard.ts` validates outbound MCP URLs against SSRF** — keep that guard in the path when touching external-MCP connection logic.
-   - `core/ai-chat/ai-chat-run.service.ts` + `ai_chat_runs` — **detached/autonomous agent runs** (`#184`), behind the per-workspace `settings.ai.autonomousRuns` flag (off by default). When on, a turn becomes a server-side RUN that survives a browser disconnect; only an explicit `POST /ai-chat/stop` ends it, and a client reconnects/live-follows via `POST /ai-chat/run`. **DEPLOY CONSTRAINT — single-instance only in phase 1:** Stop and the AbortController that backs it are process-local, so a Stop only aborts a run executing on the **same** replica that owns it (cross-instance pub/sub stop is phase 2). Do **not** enable `autonomousRuns` on a horizontally-scaled deployment (multiple replicas behind a load balancer, or Docmost cloud `CLOUD=true`) — run a single instance instead. The server logs a startup WARNING when it detects a multi-instance deployment (`CLOUD=true`) so the constraint is visible. The startup sweep settles any run left dangling by a restart.
+   - `core/ai-chat/ai-chat-run.service.ts` + `ai_chat_runs` — **every agent turn is now a first-class server-side RUN** (`#184`, universalized in `#487`): its lifecycle is tracked in `ai_chat_runs` in **both** modes, and the single-active-run-per-chat concurrency gate is enforced universally (a legacy second tab now gets a clean `409 A_RUN_ALREADY_ACTIVE` instead of a second parallel stream that interleaved history). The per-workspace `settings.ai.autonomousRuns` flag (off by default) **no longer gates whether a turn is a run** — it now controls **only the browser-disconnect semantics**: when ON the run is *detached* (a disconnect leaves it executing server-side; only an explicit `POST /ai-chat/stop` ends it, and a client reconnects/live-follows via `POST /ai-chat/run`); when OFF (legacy) a disconnect ends the turn by stopping its run via the run's stop lever. `#487` also adds a server-side **supersede** CAS ("interrupt and send now") to `POST /ai-chat/stream` (`supersede: { runId }`): it atomically stops the chat's currently-active run and waits for it to settle before the new turn claims the slot, returning `SUPERSEDE_INVALID` / `SUPERSEDE_TARGET_MISMATCH` / `SUPERSEDE_TIMEOUT` on the non-proceed branches. **DEPLOY CONSTRAINT — single-instance only in phase 1:** Stop and the AbortController that backs it are process-local, so a Stop only aborts a run executing on the **same** replica that owns it (cross-instance pub/sub stop is phase 2). Do **not** enable `autonomousRuns` on a horizontally-scaled deployment (multiple replicas behind a load balancer, or Docmost cloud `CLOUD=true`) — run a single instance instead. The server logs a startup WARNING when it detects a multi-instance deployment (`CLOUD=true`) so the constraint is visible. The startup sweep settles any run left dangling by a restart.
 
 ### Client structure
 Vite SPA. Code is organized by feature under `apps/client/src/features/*` (mirrors the server domains: `page`, `space`, `comment`, `ai-chat`, `editor`, …). Conventions:
 - **TanStack Query** for server state (one `queries/` file per feature), **Jotai** atoms for local/shared UI state, **Mantine 8** + CSS modules (`*.module.css`) + `postcss-preset-mantine` for UI.
-- The editor is Tiptap; shared node/mark extensions live in `packages/editor-ext` and are imported by **both the client and the server** (collaboration, schema, `canonicalizeFootnotes`) — editor schema changes often need to be made in `editor-ext`, not just the client. Server-side markdown import/export no longer lives in `editor-ext`: it goes through the canonical converter (#345, see below). The ProseMirror↔Markdown converter and its Docmost schema mirror now live in a SINGLE package, `@docmost/prosemirror-markdown` (#293), consumed by `mcp`, `git-sync`, and `apps/server` (#345) — do NOT reintroduce a per-package copy. `editor-ext` is the upstream source of the Tiptap schema; the package's `docmost-schema.ts` mirrors it and a serializer-contract test (`packages/prosemirror-markdown/test/serializer-contract.test.ts`) guards the boundary (every schema node must have a converter case), so a drift surfaces as a failing test rather than silent divergence. For the converter's property-testing and counterexample→fixture process (P1–P4 invariants, the `PROPERTY_SEED`/`PROPERTY_NUM_RUNS` knobs, and the nightly fuzz workflow), see `packages/prosemirror-markdown/README.md`.
+- The editor is Tiptap; shared node/mark extensions live in `packages/editor-ext` and are imported by **both the client and the server** (collaboration, schema, `canonicalizeFootnotes`) — editor schema changes often need to be made in `editor-ext`, not just the client. Server-side markdown import/export no longer lives in `editor-ext`: it goes through the canonical converter (#345, see below). The ProseMirror↔Markdown converter and its Docmost schema mirror now live in a SINGLE package, `@docmost/prosemirror-markdown` (#293), consumed by `mcp`, `git-sync`, `apps/server` (#345), and `apps/client` (#347) — do NOT reintroduce a per-package copy. The client uses the package's `browser` entry (`@docmost/prosemirror-markdown/browser`): markdown paste (`markdown-clipboard.ts`), copy-as-markdown, and AI-chat rendering now all go through the canonical converter, so the hand-written `marked`/`turndown` markdown layer that used to live in `editor-ext` was deleted (#347). The browser entry runs the HTML→DOM stage on the native `DOMParser`, so jsdom stays out of the client bundle. `editor-ext` is the upstream source of the Tiptap schema; the package's `docmost-schema.ts` mirrors it and a serializer-contract test (`packages/prosemirror-markdown/test/serializer-contract.test.ts`) guards the boundary (every schema node must have a converter case), so a drift surfaces as a failing test rather than silent divergence. For the converter's property-testing and counterexample→fixture process (P1–P4 invariants, the `PROPERTY_SEED`/`PROPERTY_NUM_RUNS` knobs, and the nightly fuzz workflow), see `packages/prosemirror-markdown/README.md`.
 - API access goes through `apps/client/src/lib/api-client.ts` (axios). The `@` alias maps to `apps/client/src`.
 - Runtime config is injected at build time by `vite.config.ts` via `define` (`APP_URL`, `COLLAB_URL`, `APP_VERSION`, …) — these come from the root `.env`, not from `import.meta.env`.
+- The build also emits `client/dist/version.json` (`{"version": …}`) from a small `vite.config.ts` plugin using the **same** `appVersion` that feeds `define.APP_VERSION`, so the file and the baked-in bundle version are identical by construction. The server reads it at startup (`ws.gateway.ts` via `readClientBuildVersion`/`resolveClientDistPath`) and announces it to each socket on connect (`app-version` event) so a tab left open across a redeploy can guard-reload before hitting a stale chunk (version-coherence). No runtime env / Dockerfile change — the file already ships in `client/dist`; missing/empty file ⇒ feature inert.
 
 ## Conventions
 
@@ -321,8 +471,10 @@ Vite SPA. Code is organized by feature under `apps/client/src/features/*` (mirro
 - **Errors must never be swallowed or shown as generic messages.** Every caught error MUST (1) be logged in full to the console/logger — error name, message, stack, `cause`, and (for HTTP/provider failures) the status code and response body — and (2) be surfaced to the user with a *specific, human-readable explanation of what actually went wrong*, never a bare generic string like "Something went wrong" / "Could not start recording" / "Transcription failed". Include the real reason (the underlying error/provider message) in the user-facing text. On the server, wrap third-party/provider failures with `describeProviderError` (or equivalent) and rethrow as a meaningful HTTP status + message — never let them collapse into an opaque 500. On the client, `console.error(<context>, err)` the raw error AND show the extracted reason (e.g. `err.response?.data?.message`, or the error `name: message`) in the notification.
 - The version string shown in the UI comes from `APP_VERSION` (CI/Docker) or `git describe --tags --always` (local), resolved in `vite.config.ts` — not from `package.json`.
 - Server TS config is permissive (`noImplicitAny: false`, `strictNullChecks: false`, `no-explicit-any` lint disabled). Follow the existing relaxed style rather than tightening types broadly.
-- Dependency versions are heavily pinned via `pnpm.overrides` and `pnpm.patchedDependencies` (`scimmy`, `yjs`, `ai`) in the root `package.json`. Don't bump pinned/patched deps casually; the patches and overrides exist for compatibility/security reasons. The `ai@6.0.134` patch disables the SDK's O(n²) cumulative `partialOutput` accumulation when no output strategy is requested (server heap OOM on long agent runs, #184; tripwire test: `apps/server/src/integrations/ai/ai-sdk-partial-output.patch.spec.ts`) — it MUST be re-created via `pnpm patch` when bumping `ai`.
-- **Adding/renaming/removing an MCP tool requires updating `SERVER_INSTRUCTIONS`** in `packages/mcp/src/index.ts` — the intent-routing guide MCP clients receive on initialize. This applies both to inline `server.registerTool(...)` calls in `index.ts` and to specs in `packages/mcp/src/tool-specs.ts`. Enforced by `packages/mcp/test/unit/server-instructions.test.mjs`, which fails when a registered tool is not mentioned in the guide (deliberate opt-outs go into its `EXCEPTIONS` list). `packages/mcp/build/` is gitignored and rebuilt in CI/Docker via `pnpm build` (same convention as `git-sync`/`prosemirror-markdown`) — never commit it; rebuild locally after editing to run the tests.
+- Dependency versions are heavily pinned via `pnpm.overrides` and `pnpm.patchedDependencies` (`scimmy`, `yjs`, `ai`) in the root `package.json`. Don't bump pinned/patched deps casually; the patches and overrides exist for compatibility/security reasons. The `ai@6.0.134` patch carries TWO independent server fixes, each with its own tripwire test: (1) it disables the SDK's O(n²) cumulative `partialOutput` accumulation when no output strategy is requested (server heap OOM on long agent runs, #184; tripwire: `apps/server/src/integrations/ai/ai-sdk-partial-output.patch.spec.ts`); (2) it fixes `writeToServerResponse`'s drain-hang — the loop awaited only `"drain"` under backpressure, so a mid-write client disconnect parked the pipe forever and leaked the reader/buffers until restart; it now races `"drain"` against `"close"`/`"error"`, cancels the reader on disconnect, and swallows the fire-and-forget read rejection (#486; tripwire: `apps/server/src/integrations/ai/ai-sdk-drain-hang.patch.spec.ts`). Both tripwires assert BOTH installed dist builds carry their patch marker. The patch MUST be re-created via `pnpm patch` when bumping `ai`.
+  - **Upstream tracking (report the analysis upstream, don't just carry it):** both `ai` fixes and the hocuspocus one are candidates for upstreaming so we can eventually drop the local patch — the analysis is already written up in each patch's `PATCH(...)` header comments. File (a) an upstream **issue** on `vercel/ai` for the O(n²) cumulative `partialOutput` accumulation (heap OOM), (b) an upstream **issue** on `vercel/ai` for the `writeToServerResponse` drain-hang, and (c) an upstream **PR** on `@hocuspocus/server` for the connect-vs-unload race (local marker `PATCH(gitmost #401)` in `patches/@hocuspocus__server@3.4.4.patch`). Do NOT edit the patch files to add links — the patch bytes feed `patch_hash` in `pnpm-lock.yaml` (`ai@6.0.134` → `e8c599b3…`), so any content change there desyncs the lockfile pin and breaks `pnpm install`; keep upstream references here instead.
+  - **`ai` version is split across the monorepo and MUST be aligned deliberately, NOT casually:** the server pins `ai@6.0.134` (patched, exact — the `patchedDependencies` key forces that version), while the client declares `ai@6.0.207` (unpatched — the server-side `writeToServerResponse`/`partialOutput` fixes are dead code in the browser, so the mismatch is currently benign but is real drift). Alignment is a **planned, install-gated step**, never a bare `package.json` edit: (1) choose the target version; (2) re-create ALL THREE patch hunks (partialOutput publish-each, the `DefaultStreamTextResult` lazy-`output` wiring, and the drain-hang race) against the target dist via `pnpm patch` — the line offsets shift between versions, so the current patch WILL fail to apply as-is; (3) run a full `pnpm install` so the lockfile + new `patch_hash` regenerate together; (4) confirm both tripwire specs still find their markers. `pnpm install` FAILS HARD on an unapplied patch — that failure is the guardrail, so treat the port as a deliberate plan rather than discovering it as a deploy-time surprise.
+- **The MCP tool inventory in `SERVER_INSTRUCTIONS` is GENERATED from the registry** (`packages/mcp/src/server-instructions.ts`: `buildToolInventory()` over `SHARED_TOOL_SPECS`) and spliced into the hand-written routing prose (`ROUTING_PROSE`). So adding/renaming/removing a **shared** spec in `packages/mcp/src/tool-specs.ts` auto-updates the `<tool_inventory>` — no manual `SERVER_INSTRUCTIONS` edit needed. Only an **inline** MCP-only tool (those registered via `server.registerTool(...)` in `index.ts`, not through the registry) needs a one-line entry in `INLINE_MCP_INVENTORY`. Enforced by `packages/mcp/test/unit/tool-inventory.test.mjs`, which fails when a registered tool is missing from the generated inventory (there is no `EXCEPTIONS` opt-out anymore — every tool must appear). Update `ROUTING_PROSE` when a tool's *intent guidance* (when-to-use) changes. `packages/mcp/build/` is gitignored and rebuilt in CI/Docker via `pnpm build` (same convention as `git-sync`/`prosemirror-markdown`) — never commit it; rebuild locally after editing to run the tests.
 
 ## CI / release
 

CHANGELOG.md

@@ -10,8 +10,151 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Breaking Changes
+
+- **External MCP tool names are now camelCase (all renamed).** Every tool on the
+  external `/mcp` surface was renamed from `snake_case` to `camelCase`, so the
+  external MCP name now matches the in-app tool name exactly (one logical tool,
+  one name everywhere). For example `get_node` → `getNode`, `edit_page_text` →
+  `editPageText`, `patch_node` → `patchNode`. The tools' behaviour, inputs and
+  outputs are unchanged — only the names change. The single-word `search`
+  keeps its name.
+
+  *Migration (external MCP clients only — the in-app AI agent already used these
+  names and is unaffected):* update anything that refers to a tool by its
+  string name — permission allowlists (`mcp__gitmost-*__get_node` →
+  `mcp__gitmost-*__getNode`), saved prompts/skills, `.mcp.json` tool filters,
+  and metrics dashboards that group by the `tool` label — and roll it out in
+  lockstep with this deploy, because the old snake_case names stop resolving.
+  Released together with the `import_page_markdown`/`update_page_markdown`
+  change below so external configs break exactly once.
+
+  Full mapping (old → new):
+
+  | Old (snake_case) | New (camelCase) |
+  | --- | --- |
+  | `check_new_comments` | `checkNewComments` |
+  | `copy_page_content` | `copyPageContent` |
+  | `create_comment` | `createComment` |
+  | `create_page` | `createPage` |
+  | `delete_comment` | `deleteComment` |
+  | `delete_node` | `deleteNode` |
+  | `delete_page` | `deletePage` |
+  | `diff_page_versions` | `diffPageVersions` |
+  | `docmost_transform` | `docmostTransform` |
+  | `drawio_create` | `drawioCreate` |
+  | `drawio_get` | `drawioGet` |
+  | `drawio_guide` | `drawioGuide` |
+  | `drawio_shapes` | `drawioShapes` |
+  | `drawio_update` | `drawioUpdate` |
+  | `edit_page_text` | `editPageText` |
+  | `export_page_markdown` | `exportPageMarkdown` |
+  | `get_node` | `getNode` |
+  | `get_outline` | `getOutline` |
+  | `get_page` | `getPage` |
+  | `get_page_json` | `getPageJson` |
+  | `get_workspace` | `getWorkspace` |
+  | `insert_footnote` | `insertFootnote` |
+  | `insert_image` | `insertImage` |
+  | `insert_node` | `insertNode` |
+  | `list_comments` | `listComments` |
+  | `list_page_history` | `listPageHistory` |
+  | `list_pages` | `listPages` |
+  | `list_shares` | `listShares` |
+  | `list_spaces` | `listSpaces` |
+  | `move_page` | `movePage` |
+  | `patch_node` | `patchNode` |
+  | `rename_page` | `renamePage` |
+  | `replace_image` | `replaceImage` |
+  | `resolve_comment` | `resolveComment` |
+  | `restore_page_version` | `restorePageVersion` |
+  | `search` | `search` (unchanged) |
+  | `search_in_page` | `searchInPage` |
+  | `share_page` | `sharePage` |
+  | `stash_page` | `stashPage` |
+  | `table_delete_row` | `tableDeleteRow` |
+  | `table_get` | `tableGet` |
+  | `table_insert_row` | `tableInsertRow` |
+  | `table_update_cell` | `tableUpdateCell` |
+  | `unshare_page` | `unsharePage` |
+  | `update_comment` | `updateComment` |
+  | `update_page_json` | `updatePageJson` |
+  | `update_page_markdown` | `updatePageMarkdown` |
+
+  (#412)
+
+- **External MCP: `import_page_markdown` removed, `update_page_markdown` added.**
+  The external `/mcp` surface no longer exposes `importPageMarkdown` (the
+  round-trip parser for a self-contained *exported* Docmost-Markdown file). In
+  its place it now exposes **`updatePageMarkdown`** — a plain-Markdown
+  full-body replace (`{pageId, content, title?}`) that pairs with
+  `updatePageJson`, re-imports the whole body (block ids regenerate) and
+  parses Docmost-flavoured markdown including `^[...]` inline footnotes.
+  *Migration:* MCP clients that called `importPageMarkdown` to overwrite a
+  page's body from Markdown should call `updatePageMarkdown` instead (pass the
+  markdown as `content`). Round-tripping an exported Docmost-Markdown file with
+  comment anchors/diagrams is no longer available on the external MCP surface;
+  export remains via `exportPageMarkdown`. The in-app AI agent is unaffected —
+  it keeps both `importPageMarkdown` and the renamed `updatePageMarkdown` (was
+  `updatePageContent`). The total MCP tool count is unchanged (−1 / +1). The
+  external names shown here are the post-#412 camelCase names. (#411)
+
+- **`getNode` now returns Markdown by default (was ProseMirror JSON).** The
+  block-level read/write tools default to Markdown so a block round trip is
+  `getNode` (markdown) → edit → `patchNode` (markdown). `getNode` now returns
+  `{ …, format: "markdown", markdown }` unless you pass `format: "json"` (which
+  restores the previous `{ …, node }` ProseMirror subtree); comment anchors —
+  including resolved ones — are preserved in the markdown so a write-back never
+  orphans a thread, and a node that cannot be a document top-level block
+  (`tableRow`/`tableCell`/`tableHeader` addressed via `#<index>`) auto-falls back
+  to JSON with `format: "json"` in the response. `patchNode`/`insertNode` gain a
+  `markdown` input alongside `node` (provide exactly one): the markdown fragment
+  may rewrite/insert several blocks at once and supports `^[...]` footnotes.
+  *Migration (external MCP clients only):* a client that consumed `getNode`'s
+  `node` field must now either read `markdown`, or pass `format: "json"` to keep
+  the old ProseMirror-JSON output. Released together with the `#411`/`#412`
+  breaking window so external configs break exactly once. (#413)
+
+- **The Prometheus `/metrics` listener now binds to `127.0.0.1` (loopback) by
+  default instead of `0.0.0.0` (all interfaces).** This closes an unauthenticated
+  endpoint that was previously reachable on every interface. **DEPLOY MIGRATION —
+  cross-container scraping breaks silently otherwise:** if your scraper runs in a
+  SEPARATE container and reaches the app as `docmost:9464` (the exact topology the
+  old `0.0.0.0` hardcode served), you MUST now set `METRICS_BIND=0.0.0.0` — and,
+  because that re-exposes the endpoint, also set `METRICS_TOKEN=<secret>` and
+  configure the scraper with a matching Bearer token. Without `METRICS_BIND`, the
+  scraper can no longer connect and metrics go dark with no error. See the
+  `METRICS_BIND` / `METRICS_TOKEN` block in `.env.example` for the migration.
+  Same-host (loopback) scrapers need no change. (#486)
+
 ### Added
 
+- **A drifted comment suggestion can be re-synced instead of failing forever
+  with a 409.** A suggestion whose stored anchor no longer matched the live
+  document used to reject every apply attempt with an unrecoverable conflict; a
+  new resync path re-reads the live anchor so the suggestion applies against the
+  current text, and orphaned anchors (whose marked run was deleted) are
+  reconciled rather than left blocking. (#496)
+- **Save intentional page versions.** Press `Cmd/Ctrl+S` (or use the page menu)
+  to save a named version of a page. The history panel now distinguishes
+  intentional versions (a "Saved" / "Agent version" badge) from automatic
+  snapshots, dims autosaves, and offers an "Only versions" filter. Automatic
+  snapshots switched from a fixed interval to a trailing idle-flush with a
+  max-wait ceiling, and a boundary snapshot is pinned whenever the editing source
+  changes (e.g. a person's edits followed by the AI agent). (#370)
+- **Open tabs pick up a new deploy on their own.** After the server is
+  redeployed while a tab is left open for hours, the tab now learns the new
+  build version over the existing WebSocket (announced per-connect, so a natural
+  reconnect delivers it) and shows a "A new version is available" banner with an
+  Update button. To avoid dropping a half-written comment or form, the tab is
+  not reloaded when you merely switch away from it; instead it auto-reloads at
+  the next safe point — the next in-app navigation (or immediately if you click
+  Update) — before it can hit a stale lazy-loaded chunk. At most one automatic
+  reload happens per 5-minute window, shared with the existing chunk-load
+  recovery, so a permanent version skew degrades to the banner rather than a
+  reload loop while a second deploy in the same tab still recovers. When the
+  build carries no version info the feature stays inert. (#481)
+
 - **Place several images side by side in a row.** A new "Inline (side by
   side)" alignment mode in the image bubble menu renders consecutive inline
   images as a row that wraps onto the next line on narrow screens. The row is
@@ -85,6 +228,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   dangling by a restart. Phase 1 is single-instance-only (cross-instance Stop is
   not yet reliable); the server warns at startup on a horizontally-scaled
   deployment. (#184)
+- **Server-side "interrupt and send now" (supersede) for AI chat.** `POST
+  /ai-chat/stream` now accepts a `supersede: { runId }` field: when the user sends
+  a new message while a run is active, the server atomically stops that run and
+  waits for it to settle before the new turn claims the chat's single run slot,
+  instead of the send being rejected as concurrent. The compare-and-set surfaces
+  three codes on its non-proceed branches — `SUPERSEDE_INVALID` (the targeted run
+  is malformed / belongs to another chat), `SUPERSEDE_TARGET_MISMATCH` (a
+  different run is now active; carries the current `activeRunId`), and
+  `SUPERSEDE_TIMEOUT` (the previous run did not stop within the settle window, so
+  nothing was sent and the composer keeps the text). Tunable via
+  `AI_CHAT_SUPERSEDE_TIMEOUT_MS` (default 10s). (#487)
 - **Out-of-band page transfer via an in-RAM blob sandbox (`stash_page`).** A
   new MCP tool serializes a whole page (its full ProseMirror JSON, with every
   internal image/file mirrored) into an ephemeral in-RAM blob and returns only
@@ -146,9 +300,56 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   by physical key position and matched against the commands; genuine Cyrillic
   search terms keep priority over remapped candidates, and short wrong-layout
   prefixes match by command title. (#283, #285, #287)
+- **Opt-in substring "lookup" search mode for agents.** `/api/search` gains an
+  additive, opt-in mode (guarded by a new `substring` flag) that matches literal
+  substrings of page titles and body text — so technical tokens the full-text
+  tokenizer mangles (`backup-srv.local`, `10.0.12.5`, `WB-MGE-30D86B`) are found
+  even when the FTS query is empty. It returns a location `path`, a windowed
+  `snippet` and a per-response relevance `score`, supports `titleOnly` and a
+  `parentPageId` subtree scope, and applies the page-level permission filter
+  before the limit. The web UI never sets `substring`, so its full-text search
+  behaviour is byte-for-byte unchanged. The leading-wildcard `LIKE` predicates
+  are backed by GIN trigram indexes on `LOWER(f_unaccent(title))` and
+  `LOWER(f_unaccent(text_content))` so lookups use a bitmap index scan instead of
+  a sequential scan. (#443)
+- **MCP `search` tool returns richer, agent-oriented results.** The external MCP
+  `search` response shape changes for the agent surface: each hit now carries
+  `pageId` (renamed from `id`), plus `path`, `snippet` and `score`; the
+  UI-oriented `spaceId`, `rank` and `highlight` fields are dropped. (#443)
 
 ### Changed
 
+- **Every AI-chat turn is now a first-class server-side run, and one run per chat
+  is enforced in both modes.** The run machinery from `#184` was universalized: a
+  turn is tracked in `ai_chat_runs` and gated by the single-active-run-per-chat
+  index regardless of the `settings.ai.autonomousRuns` flag. **Behavior change:**
+  a second tab (or a double-submit) that starts a turn while one is already active
+  on the chat is now rejected up front with `409 A_RUN_ALREADY_ACTIVE` (carrying
+  the `activeRunId`); previously, on the legacy path, it opened a second parallel
+  stream on the same chat that interleaved history. The `autonomousRuns` flag no
+  longer controls whether a turn is a run — it now governs **only** the
+  browser-disconnect semantics (ON = detached/survives a disconnect; OFF = a
+  disconnect stops the run). (#487)
+- **Vendor `ai` patch: upstream-tracking + version-alignment plan documented.**
+  The two local `ai@6.0.134` fixes (O(n²) `partialOutput` heap-OOM; the
+  `writeToServerResponse` drain-hang) and the hocuspocus connect-vs-unload race
+  now have explicit upstream-reporting and `ai`-version-alignment steps recorded
+  in `AGENTS.md` (client `ai@6.0.207` vs server `ai@6.0.134`-patched drift). The
+  patch bytes are unchanged — they feed the lockfile `patch_hash`, so the
+  alignment is called out as an install-gated plan rather than a bare version
+  bump. No runtime change.
+- **Client markdown paste/copy and AI-chat rendering now go through the canonical
+  converter.** Pasting markdown into the editor, "Copy as markdown", the AI title
+  generator, and the AI-chat markdown renderer all now use
+  `@docmost/prosemirror-markdown` (via its new `browser` entry — native
+  `DOMParser`, no jsdom in the client bundle) instead of the hand-written
+  `marked`/`turndown` markdown layer in `editor-ext`, which was **deleted**. As a
+  result, pasting canonical markdown (`^[…]` footnotes, `<!--img …-->`,
+  `> [!type]` callouts, `$…$` math, `==…==` highlight, standalone `<!--subpages-->`
+  comments) now produces the SAME nodes the server import produces for the same
+  text. Chat/reasoning markdown now renders through the editor schema (list items
+  are wrapped in `<p>`; CSS keeps them tight). (#347)
+
 - **Enabling a public share no longer auto-shares the whole sub-tree.** Turning
   a page "Shared to web" now defaults to the page alone; descendant pages become
   public only when you explicitly turn on the dedicated "Include sub-pages"
@@ -169,6 +370,98 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- **MCP write tools no longer report a false failure that provokes a duplicate
+  write.** `drawioCreate` used to throw when the diagram landed as a NESTED block
+  (anchored inside a callout or table cell) because there is no `#<index>` handle
+  for it — but the diagram was already written, so a retry-prone agent re-created
+  it and produced a duplicate. It now returns success with `nodeId: null` plus a
+  warning that explains the write landed and how to re-read it (via
+  `getOutline` / `getPageJson` by `attachmentId`). Separately, when the live
+  collaboration-session cache hits its LRU entry cap, evicting a session whose
+  write is still in flight no longer rejects that write as a hard failure — it is
+  reported as INDETERMINATE ("the update may already have persisted; verify
+  before retry") so the agent re-reads instead of blind-retrying, and a
+  still-connecting session is no longer picked as an idle eviction victim by a
+  parallel acquire. (#494)
+- **A long AI chat no longer bricks on the model's context window, and each turn
+  stops re-persisting the whole tool-output history.** Tool outputs are now
+  stored ONCE, in `metadata.parts`; the `tool_calls` trace keeps only per-step
+  outcome flags (a v2 trace shape), ending the O(N²) write amplification that
+  re-wrote every prior output on every step (measured on a live Postgres via the
+  `pg_current_wal_lsn()` delta: the trace column shrank ~3200×, the full
+  assistant row ~51%). The persisted record is unchanged in content — the full
+  history still lives in `metadata.parts`. At REPLAY time only, the history sent
+  to the provider is now bounded by a deterministic, prompt-cache-friendly token
+  budget: `floor(0.7 × chatContextWindow)` when a window is configured (no cap —
+  anti-brick protection, not a cost limiter), a flat 100k fallback for installs
+  with no window set (exactly the ones that hit terminal overflow), or off when
+  the window is explicitly `0`. Trimming truncates old tool outputs first, then
+  mechanically collapses the oldest turns, always keeping the recent turns full
+  and the tool-call/result pairing balanced. A provider context-overflow 400 is
+  now classified and used as a reactive signal: the row is stamped so the NEXT
+  turn re-trims aggressively (0.5×), which un-bricks a chat that just 400'd. The
+  client token badge and the server budgeter now share one estimator (new
+  `@docmost/token-estimate` package) so they can never diverge. Deferred-tool
+  activation is also cached in the chat metadata to avoid re-resolving it each
+  turn. (#490)
+- **Cyrillic (and any non-ASCII) draw.io labels no longer turn into mojibake
+  when a diagram is opened in the draw.io editor.** Agent-created diagrams
+  (`drawioCreate`) and Confluence-imported diagrams stored their model in the
+  SVG's `content=` attribute as base64; the draw.io editor decodes that via
+  Latin-1 `atob` (no UTF-8 step), so every non-ASCII char (e.g. `Старт-бит`,
+  `ё`, `—`) split into garbage and the editor's autosave then persisted the
+  corrupted model, breaking the page preview too. Both write paths
+  (`buildDrawioSvg`, the import service's `createDrawioSvg`) now write `content=`
+  as XML-entity-escaped mxfile XML — draw.io's own native form, decoded by the
+  DOM as UTF-8 — so labels open intact. The decoder reads both the new
+  entity-encoded form and the old base64 form, so existing diagrams still open.
+  *Healing pre-fix diagrams:* only a diagram that still holds its original
+  (correct-UTF-8) base64 — i.e. one not yet opened/autosaved in the draw.io
+  editor — can be repaired in place by `drawioGet` → `drawioUpdate` with the
+  same XML (rewrites the attachment in the new form); no migration script is
+  needed. A diagram that was already opened in the editor persisted the
+  mojibake at rest, so `drawioGet` reads the already-corrupted text and
+  `drawioUpdate` faithfully rewrites it — that text is lost and is not
+  recoverable by a rewrite. (#507)
+- **A chat with one malformed message part no longer 500s on every turn, and a
+  failed send no longer duplicates the user's message.** Incoming client parts
+  are now whitelisted to `text` (a forged tool-result part can no longer reach
+  the persisted history or the model context), and the turn is converted BEFORE
+  the user row is inserted, so a mid-flight failure cannot leave a duplicate
+  user row that a retry then compounds. A single part that still fails to convert
+  degrades to a `[tool context omitted]` marker on that one row instead of
+  bricking the whole chat. (#489)
+- **A transport drop to an external MCP server now heals within the same turn.**
+  On an undici transport error, a read-only MCP tool reconnects its server and
+  retries once within the run; a write is never auto-retried (it may already have
+  applied). One flapping server no longer nulls the shared client cache, so other
+  servers' cached clients are untouched. The SSE transport also gets a raised
+  body-timeout so a legitimate >1-min idle between the model's tool calls no
+  longer breaks a long-lived SSE socket (new `AI_MCP_SSE_BODY_TIMEOUT_MS`, default
+  10 min; see `.env.example`). (#489)
+- **Decisions on comment suggestions now leave a durable audit record.**
+  Applying or dismissing a comment suggestion hard-deletes the (childless)
+  subject comment, so the only surviving trace of who decided what is the audit
+  event — but the audit trail was wired to a Noop service that silently
+  swallowed every event. The trail is now DB-backed, so
+  `comment.suggestion_applied` / `comment.suggestion_dismissed` (and the other
+  comment-decision events) persist to the `audit` table and can be reviewed
+  after the comment is gone. A persistence failure is still swallowed with a
+  warning so it never breaks the originating request. (#496)
+- **Applying a comment suggestion no longer strips the replaced run's inline
+  formatting.** The suggested text was re-inserted carrying only the comment
+  anchor mark, silently dropping bold/italic/code/link on the affected run; the
+  prevailing formatting of the replaced run is now carried onto the applied
+  text. (#496)
+- **Markdown round-trips no longer silently drop a line that opens with a block
+  trigger.** When a document is exported to Markdown and re-imported (git-sync
+  stabilize, agent writes), a paragraph or continuation line (after a hard break)
+  that begins with a block marker — an ATX heading `#`, a blockquote/callout `>`,
+  a list marker (`-`/`*`/`+`/`N.`/`N)`), a code fence, a table `|`, a thematic
+  break (`---`), or a setext underline (`--`, `----`, or a lone `=`) — is now
+  backslash-escaped so it round-trips as text instead of being re-parsed into a
+  heading/list/quote/rule and losing its content. Front-matter stripping is
+  scoped to the import path only. (#493)
 - **The server no longer runs out of heap during long autonomous agent runs.** A
   new pnpm patch on `ai@6.0.134` stops the SDK from building a cumulative
   snapshot of the ENTIRE turn text on every streamed text-delta when no output
@@ -177,6 +470,39 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   `tee()` branch of the stream result — a ~20-step, ~28k-chunk agent run
   retained ~1.7 GB and OOM'd the 2 GB JS heap. Streaming granularity is
   unchanged; the patch must be re-created if `ai` is ever bumped. (#184)
+
+- **The server no longer leaks a hung stream pipe on every mid-run client
+  disconnect.** The same `ai@6.0.134` pnpm patch now also fixes the SDK's
+  `writeToServerResponse`, which awaited only a `"drain"` event under
+  backpressure: when a client disconnected mid-write the socket never drained, so
+  the write loop parked forever, `response.end()` was unreachable, and the stream
+  reader plus buffered chunks were pinned until process restart (every mid-run
+  disconnect in autonomous mode leaked one). The patch races `"drain"` against
+  `"close"`/`"error"`, cancels the reader and ends the response on disconnect, and
+  swallows the fire-and-forget read rejection instead of crashing on an
+  unhandledRejection. (#486)
+
+- **A failed autonomous agent-run start no longer becomes an unstoppable ghost
+  run.** When `beginRun` failed for a transient reason (e.g. a DB-pool blip),
+  the turn previously continued with NO run row — invisible to `/stop`, not
+  aborted on disconnect, and able to slip a second run past the one-run-per-chat
+  gate, leaving an unstoppable run until restart. The turn now fails fast with an
+  honest `503 A_RUN_BEGIN_FAILED` before the first byte (no orphan state), and the
+  client shows a "temporary — please try again" message instead of a misleading
+  "provider not configured". (#486)
+
+- **A pathological draw.io graph can no longer wedge the whole server.** The ELK
+  auto-layout (`layout:"elk"`) ran elkjs synchronously on the main event loop, so
+  a graph at the node/edge cap blocked ALL HTTP/SSE/loopback traffic while it
+  churned — and the old `setTimeout` "timeout" could never fire because the same
+  thread was blocked. Layout now runs in a worker thread with the timeout enforced
+  by `worker.terminate()`; the main loop stays responsive. (#486)
+
+- **The `/health` Redis probe no longer leaks a client on every tick while Redis
+  is down.** It built a new `ioredis` client per probe and disconnected it only on
+  success, so during an outage each health tick added another forever-reconnecting
+  client (an unbounded handle leak). A single long-lived probe client is now
+  reused and closed on shutdown. (#486)
 - **Internal links in exported Markdown no longer lose their visible text.** A
   link whose target page name had no file extension (e.g. a bare title) was
   collapsed to empty text during export, producing an unclickable, label-less
@@ -252,6 +578,37 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   through that exact share (its own share or an ancestor `includeSubPages`
   share); any other value now returns the generic "not found" instead of
   serving the page. (#218)
+- **MCP tool-allowlist semantics flipped: an empty `[]` now means deny-all
+  (previously it was coerced to "no restrictions").** For an external MCP server,
+  a stored `tool_allowlist` of `[]` now denies **every** tool of that server
+  (zero tools reach the agent) instead of being treated as an empty/unset filter
+  that allowed all of them. A corrupt or non-array stored value now **fails
+  closed** to deny-all rather than silently allowing everything. The admin form
+  no longer silently widens an existing deny-all server: leaving its tag field
+  empty preserves `[]` (deny-all) on save instead of NULL-ing the column to
+  allow-all, so a routine rename/toggle can no longer grant the agent every tool.
+  "No restrictions" is still expressible — a genuinely unrestricted server stores
+  NULL, and clearing the field on such a server keeps it NULL. Operationally
+  significant: audit any server that was created or left with a literal `[]`, as
+  it now exposes no tools until an explicit allowlist (or NULL) is set. (#476)
+
+- **Tool and provider error text no longer leaks to anonymous readers in the
+  public-share AI chat.** A failing tool's raw error (which could carry an
+  internal page title or a stack fragment) and a provider error (which bundles the
+  provider `statusCode` and response body — potentially the internal baseUrl or
+  model name) were streamed verbatim to the anonymous reader over SSE. Errors are
+  now sanitized at the source: the share toolset collapses any unclassified tool
+  error to a safe generic string (safe, classified tool messages still pass
+  through for the model's self-correction), and the anonymous stream `onError`
+  maps provider failures to a fixed set of neutral strings — the full detail goes
+  only to the server log. A UI render gate is layered on top. (closes #394)
+
+- **The Prometheus `/metrics` endpoint can now require Bearer authentication and
+  is loopback-bound by default.** Previously it listened on all interfaces with no
+  auth. Setting `METRICS_TOKEN` requires every scrape to present
+  `Authorization: Bearer <token>` (compared in constant time), and the listener
+  defaults to `127.0.0.1` (see the Breaking Changes entry for the cross-container
+  migration). (#486)
 
 ## [0.94.0] - 2026-06-26
 

Dockerfile

@@ -45,6 +45,11 @@ COPY --from=builder /app/packages/editor-ext/dist /app/packages/editor-ext/dist
 COPY --from=builder /app/packages/editor-ext/package.json /app/packages/editor-ext/package.json
 COPY --from=builder /app/packages/mcp/build /app/packages/mcp/build
 COPY --from=builder /app/packages/mcp/package.json /app/packages/mcp/package.json
+# The mcp package reads its data files (drawio-presets.json, drawio-shape-index.json.gz)
+# at runtime via `new URL("../../data/…", import.meta.url)` relative to build/lib/*.js,
+# i.e. from packages/mcp/data/. tsc emits only build/, so ship data/ explicitly or
+# drawioFromGraph and the shape catalog die with ENOENT on packages/mcp/data/*.
+COPY --from=builder /app/packages/mcp/data /app/packages/mcp/data
 # mcp now depends on @docmost/prosemirror-markdown (workspace:*) and eager-imports
 # it at runtime (the in-app ai-chat DocmostClient loads build/index.js -> lib/
 # markdown-converter.js). Ship the built package + its manifest, or the prod
@@ -54,6 +59,14 @@ COPY --from=builder /app/packages/mcp/package.json /app/packages/mcp/package.jso
 COPY --from=builder /app/packages/prosemirror-markdown/build /app/packages/prosemirror-markdown/build
 COPY --from=builder /app/packages/prosemirror-markdown/package.json /app/packages/prosemirror-markdown/package.json
 
+# apps/server imports @docmost/token-estimate (workspace:*) at runtime
+# (history-budget.ts, #490). tsc emits only dist/ and dist/ is gitignored, so the
+# prod install would resolve a broken workspace symlink and the server would die
+# with ERR_MODULE_NOT_FOUND on the first history-budget call. Ship the built
+# package + its manifest, mirroring prosemirror-markdown above.
+COPY --from=builder /app/packages/token-estimate/dist /app/packages/token-estimate/dist
+COPY --from=builder /app/packages/token-estimate/package.json /app/packages/token-estimate/package.json
+
 # Copy root package files
 COPY --from=builder /app/package.json /app/package.json
 COPY --from=builder /app/pnpm*.yaml /app/
@@ -81,4 +94,14 @@ VOLUME ["/app/data/storage"]
 
 EXPOSE 3000
 
+# DEPLOY REQUIREMENT — SINGLE INSTANCE or STICKY SESSIONS (#449).
+# MCP content writes are serialized per page by an IN-PROCESS mutex, and the
+# stash_page blob store + cached collab sessions are RAM-only and process-local.
+# Running MULTIPLE replicas of this image behind a load balancer WITHOUT sticky
+# sessions silently breaks per-page write serialization (two replicas can lock
+# the same page at once) and makes stash_page blobs unreachable across replicas.
+# Run a SINGLE instance, or pin each page's traffic to one replica (sticky
+# sessions / consistent hashing on page id). There is deliberately no
+# cross-process lock yet — a conscious constraint. See .env.example (the "MCP
+# collaboration write path" block) and packages/mcp/README.md for details.
 CMD ["pnpm", "start"]

README.md

@@ -206,6 +206,137 @@ start the new migrations apply on top of your existing schema (`CREATE EXTENSION
   existing pages are indexed on their next edit. pgvector is still required for the migration to
   apply at all.
 
+## Local embeddings server
+
+The AI agent's semantic (RAG) search needs an **embeddings model**. Instead of paying a cloud
+provider (e.g. OpenAI `text-embedding-3-*`) to embed every page, you can run a small open-weights
+model yourself with Hugging Face
+[Text Embeddings Inference](https://github.com/huggingface/text-embeddings-inference) (TEI), which
+serves an OpenAI-compatible `/v1/embeddings` endpoint. `intfloat/multilingual-e5-small` is a good
+default: multilingual, 384-dim, and comfortable on CPU (~1–2 GB RAM, 1–2 vCPU). Point Gitmost at it
+under **Workspace settings → AI → Embeddings**.
+
+### Option A — local (same Docker network as Gitmost)
+
+Run TEI as a container on the network Gitmost is already on. The port is never published, so the
+endpoint stays internal and needs no authentication.
+
+```yaml
+services:
+  embeddings:
+    image: ghcr.io/huggingface/text-embeddings-inference:cpu-1.9   # pin version; use a cuda-* tag for GPU
+    container_name: embeddings
+    restart: unless-stopped
+    networks:
+      - gitmost_net          # same network Gitmost is on
+    command:
+      - "--model-id"
+      - "intfloat/multilingual-e5-small"
+      - "--auto-truncate"    # clamp over-long inputs instead of returning 413
+    volumes:
+      - tei-models:/data     # weights are downloaded once and cached here
+
+networks:
+  gitmost_net:
+    external: true           # the network Gitmost already uses
+
+volumes:
+  tei-models:
+```
+
+Gitmost settings (**Workspace settings → AI → Embeddings**):
+
+| Field             | Value                             |
+|-------------------|-----------------------------------|
+| Model             | `intfloat/multilingual-e5-small`  |
+| Base URL          | `http://embeddings:80/v1/`        |
+| Embedding API key | — (leave empty)                   |
+
+> `embeddings` is the container name — Gitmost resolves it over DNS inside the Docker network.
+> The port is not published, so the endpoint is reachable only by containers on that network and
+> no authorization is required.
+
+### Option B — separate host (public via Traefik + Let's Encrypt)
+
+This assumes the host already runs Traefik with an ACME resolver (the example below uses
+`letsEncrypt`, the `websecure` entrypoint and a shared `docker_main_net` network). Replace the
+domain / network / resolver with your own.
+
+**DNS:** add an A record `embeddings.example.com` → the IP of your Traefik host (same
+challenge / port 80 as the rest of your sites).
+
+```yaml
+services:
+  embeddings:
+    image: ghcr.io/huggingface/text-embeddings-inference:cpu-1.9   # pin version; cuda-* tag for GPU
+    container_name: embeddings
+    restart: unless-stopped
+    networks:
+      - docker_main_net      # the network Traefik is attached to
+    command:
+      - "--model-id"
+      - "intfloat/multilingual-e5-small"
+      - "--auto-truncate"
+      - "--api-key"
+      - "sk-emb-REPLACE_WITH_YOUR_KEY"
+    volumes:
+      - tei-models:/data
+    labels:
+      traefik.enable: "true"
+      traefik.http.routers.embeddings.rule: "Host(`embeddings.example.com`)"
+      traefik.http.routers.embeddings.entrypoints: "websecure"
+      traefik.http.routers.embeddings.tls: "true"
+      traefik.http.routers.embeddings.tls.certresolver: "letsEncrypt"
+      traefik.http.routers.embeddings.service: "embeddings"
+      traefik.http.services.embeddings.loadbalancer.server.port: "80"
+      # TEI enforces the Bearer key itself; Traefik only rate-limits to protect the CPU
+      traefik.http.routers.embeddings.middlewares: "embeddings-rl"
+      traefik.http.middlewares.embeddings-rl.ratelimit.average: "20"
+      traefik.http.middlewares.embeddings-rl.ratelimit.burst: "40"
+      traefik.http.middlewares.embeddings-rl.ratelimit.period: "1s"
+
+networks:
+  docker_main_net:
+    external: true
+
+volumes:
+  tei-models:
+```
+
+Gitmost settings (**Workspace settings → AI → Embeddings**):
+
+| Field             | Value                                 |
+|-------------------|---------------------------------------|
+| Model             | `intfloat/multilingual-e5-small`      |
+| Base URL          | `https://embeddings.example.com/v1/`  |
+| Embedding API key | your `sk-emb-…`                       |
+
+Check it from outside:
+
+```bash
+curl -s https://embeddings.example.com/v1/embeddings \
+  -H "Authorization: Bearer sk-emb-REPLACE_WITH_YOUR_KEY" \
+  -H "Content-Type: application/json" \
+  -d '{"model":"intfloat/multilingual-e5-small","input":"query: hello"}' \
+  | python3 -c 'import sys,json;print("dims:",len(json.load(sys.stdin)["data"][0]["embedding"]))'
+# -> dims: 384
+```
+
+### Embeddings server notes
+
+- **Vector dimension is 384.** If this Gitmost was previously embedded with a different model
+  (e.g. `text-embedding-3-large` = 3072-dim), the old pgvector rows won't match the new dimension —
+  clear the existing embeddings / re-index before switching. Gitmost only compares vectors of the
+  same dimension, so mixed-dimension rows are silently ignored rather than searched.
+- **First start downloads the weights** (hundreds of MB) from `huggingface.co` into the
+  `tei-models` volume; every start after that reads from the volume.
+- **Pin the version.** Pin the image, and optionally the model: add `--revision <commit-sha>` to
+  `command` (the sha is on the model's page on Hugging Face).
+- **Air-gapped / no egress:** seed the `tei-models` volume ahead of time and add
+  `environment: [HF_HUB_OFFLINE=1]`.
+- **GPU:** use the cuda tag of the same release (e.g.
+  `ghcr.io/huggingface/text-embeddings-inference:cuda-1.9`) and start the container with `gpus: all`.
+
 ## Features
 
 - Real-time collaboration

README.ru.md

@@ -193,6 +193,137 @@ dump/restore, существующий каталог данных переис
 > неизменным и бэкапьте вместе с базой данных.
 
 
+## Локальный сервер эмбеддингов
+
+Семантическому (RAG) поиску AI-агента нужна **модель эмбеддингов**. Вместо оплаты облачного
+провайдера (например, OpenAI `text-embedding-3-*`) за эмбеддинг каждой страницы можно запустить
+небольшую open-weights модель у себя через Hugging Face
+[Text Embeddings Inference](https://github.com/huggingface/text-embeddings-inference) (TEI) — он
+отдаёт OpenAI-совместимый эндпоинт `/v1/embeddings`. Хороший дефолт — `intfloat/multilingual-e5-small`:
+многоязычная, 384-мерная, комфортно работает на CPU (~1–2 ГБ RAM, 1–2 vCPU). Пропишите её в
+**Настройки воркспейса → AI → Эмбеддинги**.
+
+### Вариант A — локально (та же Docker-сеть, что и Gitmost)
+
+Запустите TEI контейнером в той же сети, где уже работает Gitmost. Порт наружу не публикуется,
+поэтому эндпоинт остаётся внутренним и не требует авторизации.
+
+```yaml
+services:
+  embeddings:
+    image: ghcr.io/huggingface/text-embeddings-inference:cpu-1.9   # pin version; use a cuda-* tag for GPU
+    container_name: embeddings
+    restart: unless-stopped
+    networks:
+      - gitmost_net          # same network Gitmost is on
+    command:
+      - "--model-id"
+      - "intfloat/multilingual-e5-small"
+      - "--auto-truncate"    # clamp over-long inputs instead of returning 413
+    volumes:
+      - tei-models:/data     # weights are downloaded once and cached here
+
+networks:
+  gitmost_net:
+    external: true           # the network Gitmost already uses
+
+volumes:
+  tei-models:
+```
+
+Настройки Gitmost (**Настройки воркспейса → AI → Эмбеддинги**):
+
+| Поле              | Значение                          |
+|-------------------|-----------------------------------|
+| Model             | `intfloat/multilingual-e5-small`  |
+| Base URL          | `http://embeddings:80/v1/`        |
+| Embedding API key | — (оставить пустым)               |
+
+> `embeddings` — имя контейнера, Gitmost резолвит его по DNS внутри Docker-сети.
+> Наружу порт не публикуется, эндпоинт доступен только контейнерам этой сети, поэтому
+> авторизация не нужна.
+
+### Вариант B — на отдельном хосте (наружу через Traefik + Let's Encrypt)
+
+Предполагается, что на хосте уже есть Traefik с ACME-резолвером (в примере ниже — `letsEncrypt`,
+entrypoint `websecure`, общая сеть `docker_main_net`). Замените домен / сеть / резолвер на свои.
+
+**DNS:** заведите A-запись `embeddings.example.com` → IP хоста с Traefik (тот же challenge / порт 80,
+что и у остальных сайтов).
+
+```yaml
+services:
+  embeddings:
+    image: ghcr.io/huggingface/text-embeddings-inference:cpu-1.9   # pin version; cuda-* tag for GPU
+    container_name: embeddings
+    restart: unless-stopped
+    networks:
+      - docker_main_net      # the network Traefik is attached to
+    command:
+      - "--model-id"
+      - "intfloat/multilingual-e5-small"
+      - "--auto-truncate"
+      - "--api-key"
+      - "sk-emb-REPLACE_WITH_YOUR_KEY"
+    volumes:
+      - tei-models:/data
+    labels:
+      traefik.enable: "true"
+      traefik.http.routers.embeddings.rule: "Host(`embeddings.example.com`)"
+      traefik.http.routers.embeddings.entrypoints: "websecure"
+      traefik.http.routers.embeddings.tls: "true"
+      traefik.http.routers.embeddings.tls.certresolver: "letsEncrypt"
+      traefik.http.routers.embeddings.service: "embeddings"
+      traefik.http.services.embeddings.loadbalancer.server.port: "80"
+      # TEI enforces the Bearer key itself; Traefik only rate-limits to protect the CPU
+      traefik.http.routers.embeddings.middlewares: "embeddings-rl"
+      traefik.http.middlewares.embeddings-rl.ratelimit.average: "20"
+      traefik.http.middlewares.embeddings-rl.ratelimit.burst: "40"
+      traefik.http.middlewares.embeddings-rl.ratelimit.period: "1s"
+
+networks:
+  docker_main_net:
+    external: true
+
+volumes:
+  tei-models:
+```
+
+Настройки Gitmost (**Настройки воркспейса → AI → Эмбеддинги**):
+
+| Поле              | Значение                              |
+|-------------------|---------------------------------------|
+| Model             | `intfloat/multilingual-e5-small`      |
+| Base URL          | `https://embeddings.example.com/v1/`  |
+| Embedding API key | ваш `sk-emb-…`                        |
+
+Проверка снаружи:
+
+```bash
+curl -s https://embeddings.example.com/v1/embeddings \
+  -H "Authorization: Bearer sk-emb-REPLACE_WITH_YOUR_KEY" \
+  -H "Content-Type: application/json" \
+  -d '{"model":"intfloat/multilingual-e5-small","input":"query: hello"}' \
+  | python3 -c 'import sys,json;print("dims:",len(json.load(sys.stdin)["data"][0]["embedding"]))'
+# -> dims: 384
+```
+
+### Заметки про сервер эмбеддингов
+
+- **Размерность вектора — 384.** Если раньше этот Gitmost эмбеддился другой моделью
+  (например, `text-embedding-3-large` = 3072-dim), старые строки в pgvector не совпадут по
+  размерности — очистите существующие эмбеддинги / переиндексируйте перед переключением. Gitmost
+  сравнивает только вектора одной размерности, поэтому строки другой размерности не участвуют в
+  поиске, а не ломают его.
+- **Первый старт тянет веса** (сотни МБ) с `huggingface.co` в том `tei-models`; дальше — из тома.
+- **Пин версии.** Пиньте образ, а при желании и модель: добавьте в `command` `--revision <commit-sha>`
+  (sha берётся со страницы модели на Hugging Face).
+- **Без egress (air-gapped):** засейте том `tei-models` заранее и добавьте
+  `environment: [HF_HUB_OFFLINE=1]`.
+- **GPU:** возьмите cuda-тег того же релиза (например,
+  `ghcr.io/huggingface/text-embeddings-inference:cuda-1.9`) и запустите контейнер с `gpus: all`.
+
+
 ## Возможности
 
 - Совместная работа в реальном времени

apps/client/package.json

@@ -21,6 +21,8 @@
     "@atlaskit/pragmatic-drag-and-drop-live-region": "1.3.4",
     "@casl/react": "5.0.1",
     "@docmost/editor-ext": "workspace:*",
+    "@docmost/prosemirror-markdown": "workspace:*",
+    "@docmost/token-estimate": "workspace:*",
     "@excalidraw/excalidraw": "0.18.0-3a5ef40",
     "@mantine/core": "8.3.18",
     "@mantine/dates": "8.3.18",

apps/client/public/locales/en-US/translation.json

@@ -1,4 +1,5 @@
 {
+  "A new version is available": "A new version is available",
   "Account": "Account",
   "Active": "Active",
   "Add": "Add",
@@ -239,6 +240,8 @@
   "Comment re-opened successfully": "Comment re-opened successfully",
   "Comment unresolved successfully": "Comment unresolved successfully",
   "Failed to resolve comment": "Failed to resolve comment",
+  "Failed to re-open comment": "Failed to re-open comment",
+  "Comment no longer exists": "Comment no longer exists",
   "Resolve comment": "Resolve comment",
   "Unresolve comment": "Unresolve comment",
   "Resolve Comment Thread": "Resolve Comment Thread",
@@ -1418,5 +1421,29 @@
   "The commented text changed since this suggestion was made; it was not applied.": "The commented text changed since this suggestion was made; it was not applied.",
   "Dismiss": "Dismiss",
   "Suggestion dismissed": "Suggestion dismissed",
-  "Failed to dismiss suggestion": "Failed to dismiss suggestion"
+  "Failed to dismiss suggestion": "Failed to dismiss suggestion",
+  "Save version": "Save version",
+  "Ctrl+S": "Ctrl+S",
+  "Version saved": "Version saved",
+  "Already saved as the latest version": "Already saved as the latest version",
+  "Agent version": "Agent version",
+  "Boundary": "Boundary",
+  "Autosave": "Autosave",
+  "Only versions": "Only versions",
+  "No saved versions yet.": "No saved versions yet.",
+  "Time worked on this article": "Time worked on this article",
+  "Show time worked on this page": "Show time worked on this page",
+  "Estimated time worked (inactivity gap {{gap}} min)": "Estimated time worked (inactivity gap {{gap}} min)",
+  "Estimate · timezone {{tz}} · inactivity gap {{gap}} min": "Estimate · timezone {{tz}} · inactivity gap {{gap}} min",
+  "No editing activity recorded yet.": "No editing activity recorded yet.",
+  "× {{count}} days without edits": "× {{count}} days without edits",
+  "agent: {{value}}": "agent: {{value}}",
+  "Work": "Work",
+  "Agent": "Agent",
+  "≈ {{hours}}h {{minutes}}m": "≈ {{hours}}h {{minutes}}m",
+  "≈ {{hours}}h": "≈ {{hours}}h",
+  "≈ {{minutes}}m": "≈ {{minutes}}m",
+  "{{hours}}h {{minutes}}m": "{{hours}}h {{minutes}}m",
+  "{{hours}}h": "{{hours}}h",
+  "{{minutes}}m": "{{minutes}}m"
 }

apps/client/public/locales/ru-RU/translation.json

@@ -1,4 +1,5 @@
 {
+  "A new version is available": "Доступна новая версия",
   "Account": "Аккаунт",
   "Active": "Активный",
   "Add": "Добавить",
@@ -239,6 +240,8 @@
   "Comment re-opened successfully": "Комментарий успешно открыт повторно",
   "Comment unresolved successfully": "Комментарий успешно переведён в нерешённые",
   "Failed to resolve comment": "Не удалось разрешить комментарий",
+  "Failed to re-open comment": "Не удалось переоткрыть комментарий",
+  "Comment no longer exists": "Комментарий больше не существует",
   "Resolve comment": "Решить комментарий",
   "Unresolve comment": "Снять статус решённого с комментария",
   "Resolve Comment Thread": "Решить ветку комментариев",
@@ -256,6 +259,9 @@
   "Invite link": "Ссылка для приглашения",
   "Copy": "Копировать",
   "Copy to space": "Копировать в пространство",
+  "Copy chat": "Копировать чат",
+  "Dock to sidebar": "Закрепить в боковой панели",
+  "Undock": "Открепить",
   "Copied": "Скопировано",
   "Failed to export chat": "Не удалось экспортировать чат",
   "Duplicate": "Дублировать",
@@ -285,6 +291,9 @@
   "Alt text": "Альтернативный текст",
   "Describe this for accessibility.": "Опишите это для специальных возможностей.",
   "Add a description": "Добавить описание",
+  "Caption": "Подпись",
+  "Add a caption": "Добавить подпись",
+  "Shown below the image.": "Отображается под изображением.",
   "Justify": "По ширине",
   "Merge cells": "Объединить ячейки",
   "Split cell": "Разделить ячейку",
@@ -388,22 +397,6 @@
   "Quote": "Цитата",
   "Image": "Изображение",
   "Audio": "Аудио",
-  "Transcribe": "Транскрибировать",
-  "Transcribing…": "Транскрибация…",
-  "No speech detected": "Речь не распознана",
-  "Transcription failed": "Не удалось распознать речь",
-  "Voice dictation is not configured": "Голосовой ввод не настроен",
-  "Start dictation": "Начать диктовку",
-  "Stop recording": "Остановить запись",
-  "Microphone access denied": "Доступ к микрофону запрещён",
-  "No microphone found": "Микрофон не найден",
-  "Microphone is unavailable or already in use": "Микрофон недоступен или уже используется",
-  "Could not start recording": "Не удалось начать запись",
-  "Audio recording is not available in this browser/context": "Запись аудио недоступна в этом браузере/контексте",
-  "Dictation": "Диктовка",
-  "Dictation becomes available once the page finishes connecting": "Диктовка станет доступна после подключения к документу",
-  "No connection to the collaboration server — dictation unavailable": "Нет связи с сервером совместного редактирования — диктовка недоступна",
-  "This page is read-only": "Страница открыта только для чтения",
   "Embed PDF": "Встроить PDF",
   "Upload and embed a PDF file.": "Загрузите и встроите PDF-файл.",
   "Embed as PDF": "Встроить как PDF",
@@ -419,9 +412,6 @@
   "Footnote {{number}}": "Сноска {{number}}",
   "Go to footnote": "Перейти к сноске",
   "Back to reference": "Вернуться к ссылке",
-  "Back to references": "Вернуться к ссылкам",
-  "Back to reference {{label}}": "Вернуться к ссылке {{label}}",
-  "Empty footnote": "Пустая сноска",
   "Math inline": "Строчная формула",
   "Insert inline math equation.": "Вставить математическое выражение в строку.",
   "Math block": "Блок формулы",
@@ -447,6 +437,9 @@
   "{{count}} command available_other": "Доступно {{count}} команд",
   "{{count}} result available_one": "Доступен 1 результат",
   "{{count}} result available_other": "Доступно {{count}} результатов",
+  "{{count}} result found_one": "Найден {{count}} результат",
+  "{{count}} result found_few": "Найдено {{count}} результата",
+  "{{count}} result found_other": "Найдено {{count}} результатов",
   "Equal columns": "Равные столбцы",
   "Left sidebar": "Левая боковая панель",
   "Right sidebar": "Правая боковая панель",
@@ -456,6 +449,7 @@
   "Names do not match": "Названия не совпадают",
   "Today, {{time}}": "Сегодня, {{time}}",
   "Yesterday, {{time}}": "Вчера, {{time}}",
+  "now": "сейчас",
   "Space created successfully": "Пространство успешно создано",
   "Space updated successfully": "Пространство успешно обновлено",
   "Space deleted successfully": "Пространство успешно удалено",
@@ -559,6 +553,7 @@
   "Add 2FA method": "Добавить метод 2FA",
   "Backup codes": "Резервные коды",
   "Disable": "Отключить",
+  "disabled": "отключено",
   "Invalid verification code": "Недействительный код подтверждения",
   "New backup codes have been generated": "Новые резервные коды сгенерированы",
   "Failed to regenerate backup codes": "Не удалось заново сгенерировать резервные коды",
@@ -702,62 +697,6 @@
   "AI search": "Поиск ИИ",
   "AI Answer": "Ответ ИИ",
   "Ask AI": "Спросить ИИ",
-  "AI agent": "AI-агент",
-  "Take a look at the current document": "Посмотри текущий документ",
-  "Start automatically": "Запускать автоматически",
-  "When on, picking this role sends a launch message and starts the chat. When off, the role is selected and you type the first message yourself.": "Когда включено, выбор этой роли отправляет стартовое сообщение и начинает чат. Когда выключено, роль выбирается, а первое сообщение вы вводите сами.",
-  "Launch message": "Стартовое сообщение",
-  "Sent automatically when this role is picked. Leave empty to use the default text. Ignored when “Start automatically” is off.": "Отправляется автоматически при выборе этой роли. Оставьте пустым, чтобы использовать текст по умолчанию. Игнорируется, когда «Запускать автоматически» выключено.",
-  "AI agent is typing…": "AI-агент печатает…",
-  "{{name}} is typing…": "{{name}} печатает…",
-  "Thinking…": "Думаю…",
-  "Thinking… · {{count}} tokens": "Думаю… · {{count}} токенов",
-  "Thinking… · {{count}} tokens_one": "Думаю… · {{count}} токен",
-  "Thinking… · {{count}} tokens_few": "Думаю… · {{count}} токена",
-  "Thinking… · {{count}} tokens_many": "Думаю… · {{count}} токенов",
-  "Thinking · {{count}} tokens": "Размышления · {{count}} токенов",
-  "Thinking · {{count}} tokens_one": "Размышления · {{count}} токен",
-  "Thinking · {{count}} tokens_few": "Размышления · {{count}} токена",
-  "Thinking · {{count}} tokens_many": "Размышления · {{count}} токенов",
-  "Agent role": "Роль агента",
-  "AI chat": "AI-чат",
-  "AI chat is disabled for this workspace.": "AI-чат отключён для этого рабочего пространства.",
-  "Ask a question about this documentation.": "Задайте вопрос об этой документации.",
-  "Ask a question…": "Задайте вопрос…",
-  "Ask the AI agent anything about your workspace.": "Спросите AI-агента о чём угодно по вашему рабочему пространству.",
-  "Ask the AI agent…": "Спросите AI-агента…",
-  "Copy chat": "Копировать чат",
-  "Dock to sidebar": "Закрепить в боковой панели",
-  "Undock": "Открепить",
-  "Created successfully": "Успешно создано",
-  "Context size / model limit": "Размер контекста / лимит модели",
-  "Context window (tokens)": "Окно контекста (токены)",
-  "Shown as used / total in the chat header. Leave empty to hide the limit.": "Показывается в шапке чата как использовано / всего. Пусто — лимит скрыт.",
-  "Delete this chat?": "Удалить этот чат?",
-  "Deleted successfully": "Успешно удалено",
-  "AI agent «{{role}}» on behalf of {{person}}": "AI-агент «{{role}}» от имени {{person}}",
-  "AI agent {{name}}": "AI-агент {{name}}",
-  "Failed to delete chat": "Не удалось удалить чат",
-  "Failed to rename chat": "Не удалось переименовать чат",
-  "Failed": "Ошибка",
-  "OK · {{n}}": "OK · {{n}}",
-  "Test": "Тест",
-  "No tools available": "Инструменты недоступны",
-  "Available tools": "Доступные инструменты",
-  "Minimize": "Свернуть",
-  "No chats yet.": "Чатов пока нет.",
-  "Send": "Отправить",
-  "Send when the agent finishes": "Отправить, когда агент закончит",
-  "Queue message": "Поставить в очередь",
-  "Remove queued message": "Убрать из очереди",
-  "Send now": "Отправить сейчас",
-  "Interrupt and send now": "Прервать и отправить сейчас",
-  "Something went wrong": "Что-то пошло не так",
-  "Stop": "Стоп",
-  "The AI agent could not respond. Please try again.": "AI-агент не смог ответить. Попробуйте ещё раз.",
-  "The AI provider is not configured. Ask an administrator to set it up.": "AI-провайдер не настроен. Попросите администратора настроить его.",
-  "Universal assistant": "Универсальный ассистент",
-  "You": "Вы",
   "AI is thinking...": "ИИ обрабатывает запрос...",
   "Thinking": "Думаю",
   "Ask a question...": "Задайте вопрос...",
@@ -784,8 +723,40 @@
   "Manage API keys for all users in the workspace. View the <anchor>API documentation</anchor> for usage details.": "Управляйте API-ключами для всех пользователей в рабочем пространстве. Смотрите <anchor>документацию по API</anchor> для получения информации об использовании.",
   "View the <anchor>API documentation</anchor> for usage details.": "Смотрите <anchor>документацию по API</anchor> для получения информации об использовании.",
   "View the <anchor>MCP documentation</anchor>.": "Смотрите <anchor>документацию по MCP</anchor>.",
-  "Instructions": "Инструкции",
+  "AI / Models": "ИИ / Модели",
+  "AI / External tools (MCP)": "ИИ / Внешние инструменты (MCP)",
+  "Add server": "Добавить сервер",
+  "Edit server": "Изменить сервер",
+  "Delete server": "Удалить сервер",
+  "Are you sure you want to delete this MCP server?": "Вы уверены, что хотите удалить этот MCP-сервер?",
+  "No external servers configured": "Внешние серверы не настроены",
+  "Server name": "Имя сервера",
+  "Transport": "Транспорт",
+  "URL": "URL",
+  "Authorization header": "Заголовок авторизации",
+  "Tool allowlist": "Список разрешённых инструментов",
+  "Optional. Leave empty to allow all tools the server exposes.": "Необязательно. Оставьте пустым, чтобы разрешить все инструменты, которые предоставляет сервер.",
   "Optional guidance for the agent on how and when to use this server's tools. Injected into the system prompt. The server's tools are namespaced as \"<server name>_*\".": "Необязательное указание агенту, как и когда использовать инструменты этого сервера. Добавляется в системный промпт. Инструменты сервера именуются с префиксом «<имя сервера>_*».",
+  "Test": "Тест",
+  "Available tools": "Доступные инструменты",
+  "No tools available": "Инструменты недоступны",
+  "Failed": "Ошибка",
+  "OK · {{n}}": "OK · {{n}}",
+  "Created successfully": "Успешно создано",
+  "Deleted successfully": "Успешно удалено",
+  "Clear": "Очистить",
+  "Provider": "Провайдер",
+  "•••• set": "•••• задан",
+  "Clear key": "Очистить ключ",
+  "Base URL": "Базовый URL",
+  "Chat model": "Модель чата",
+  "Embedding model": "Модель эмбеддингов",
+  "System message": "Системное сообщение",
+  "A built-in safety framework is always appended.": "Встроенный набор правил безопасности всегда добавляется автоматически.",
+  "Test connection": "Проверить соединение",
+  "Connection successful": "Соединение установлено",
+  "Connection failed": "Не удалось установить соединение",
+  "Only workspace admins can manage AI provider settings.": "Управлять настройками провайдера ИИ могут только администраторы рабочего пространства.",
   "Sources": "Источники",
   "AI Answers not available for attachments": "Ответы ИИ недоступны для вложений",
   "No answer available": "Ответ недоступен",
@@ -1013,6 +984,7 @@
   "Try again": "Попробовать снова",
   "Untitled chat": "Чат без названия",
   "No document": "Без документа",
+  "You": "Вы",
   "What can I help you with?": "Чем я могу вам помочь?",
   "Are you sure you want to revoke this {{credential}}": "Вы уверены, что хотите отозвать этот {{credential}}",
   "Automatically provision users and groups from your identity provider via SCIM.": "Автоматически предоставляйте доступ пользователям и группам из вашего провайдера удостоверений через SCIM.",
@@ -1041,6 +1013,9 @@
   "Page menu": "Меню страницы",
   "Expand": "Развернуть",
   "Collapse": "Свернуть",
+  "Expand all": "Развернуть все",
+  "Collapse all": "Свернуть все",
+  "Couldn't expand the tree: {{reason}}": "Не удалось развернуть дерево: {{reason}}",
   "Comment menu": "Меню комментария",
   "Group menu": "Меню группы",
   "Show hidden breadcrumbs": "Показать скрытые хлебные крошки",
@@ -1077,7 +1052,7 @@
   "Search pages and spaces...": "Поиск страниц и пространств...",
   "No results found": "Результаты не найдены",
   "You don't have permission to create pages here": "У вас нет прав на создание страниц здесь",
-  "Chat menu": "Меню чата",
+  "Chat menu for {{title}}": "Меню чата для {{title}}",
   "API key menu": "Меню API-ключа",
   "Jump to comment selection": "Перейти к выбору комментария",
   "Slash commands": "Команды со слешем",
@@ -1131,6 +1106,9 @@
   "Undo": "Отменить",
   "Redo": "Повторить",
   "Backlinks": "Обратные ссылки",
+  "Back to references": "Вернуться к ссылкам",
+  "Back to reference {{label}}": "Вернуться к ссылке {{label}}",
+  "Empty footnote": "Пустая сноска",
   "Last updated by": "Последний изменивший",
   "Last updated": "Последнее обновление",
   "Stats": "Статистика",
@@ -1164,6 +1142,7 @@
   "Page title": "Заголовок страницы",
   "Page content": "Содержимое страницы",
   "Member actions": "Действия с участником",
+  "Member actions for {{name}}": "Действия с участником {{name}}",
   "Toggle password visibility": "Переключить видимость пароля",
   "Send comment": "Отправить комментарий",
   "Token actions": "Действия с токеном",
@@ -1183,11 +1162,187 @@
   "Removed from favorites": "Удалено из избранного",
   "Added {{name}} to favorites": "{{name}} добавлено в избранное",
   "Removed {{name}} from favorites": "{{name}} удалено из избранного",
+  "Label added": "Метка добавлена",
+  "Label removed": "Метка удалена",
+  "Image updated": "Изображение обновлено",
+  "Unsupported image type": "Неподдерживаемый тип изображения",
+  "Member deactivated": "Участник деактивирован",
+  "Member activated": "Участник активирован",
+  "Name is required": "Укажите имя",
+  "Name must be 40 characters or fewer": "Имя должно содержать не более 40 символов",
+  "Group name must be at least 2 characters": "Название группы должно содержать не менее 2 символов",
+  "Group name must be 100 characters or fewer": "Название группы должно содержать не более 100 символов",
+  "Description must be 500 characters or fewer": "Описание должно содержать не более 500 символов",
+  "Invalid invitation link": "Недействительная ссылка-приглашение",
   "Page menu for {{name}}": "Меню страницы для {{name}}",
   "Create subpage of {{name}}": "Создать подстраницу для {{name}}",
+  "AI chat": "AI-чат",
+  "Ask a question about this documentation.": "Задайте вопрос об этой документации.",
+  "Ask a question…": "Задайте вопрос…",
+  "Thinking…": "Думаю…",
+  "Thinking… · {{count}} tokens": "Думаю… · {{count}} токенов",
+  "Thinking… · {{count}} tokens_one": "Думаю… · {{count}} токен",
+  "Thinking… · {{count}} tokens_few": "Думаю… · {{count}} токена",
+  "Thinking… · {{count}} tokens_many": "Думаю… · {{count}} токенов",
+  "Thinking… · {{count}} tokens_other": "Думаю… · {{count}} токенов",
+  "Thinking · {{count}} tokens": "Размышления · {{count}} токенов",
+  "Thinking · {{count}} tokens_one": "Размышления · {{count}} токен",
+  "Thinking · {{count}} tokens_few": "Размышления · {{count}} токена",
+  "Thinking · {{count}} tokens_many": "Размышления · {{count}} токенов",
+  "Thinking · {{count}} tokens_other": "Размышления · {{count}} токенов",
+  "The assistant is unavailable right now. Please try again.": "Ассистент сейчас недоступен. Попробуйте ещё раз.",
+  "Public share assistant": "Ассистент публичного доступа",
+  "Let anonymous visitors of public shares ask an AI assistant scoped to that share's pages. You pay for the tokens.": "Позвольте анонимным посетителям публичных ссылок обращаться к ИИ-ассистенту в рамках страниц этой публикации. Токены оплачиваете вы.",
+  "Public assistant model": "Модель публичного ассистента",
+  "Defaults to the chat model": "По умолчанию используется модель чата",
+  "Optional cheaper model id for the public assistant. Empty uses the chat model above.": "Необязательный более дешёвый идентификатор модели для публичного ассистента. Если пусто, используется модель чата выше.",
+  "Assistant identity": "Личность ассистента",
+  "Pick an agent role whose persona the public assistant adopts. The safety rules always still apply.": "Выберите роль агента, чью личность примет публичный ассистент. Правила безопасности всегда остаются в силе.",
+  "Built-in assistant persona": "Встроенная личность ассистента",
+  "Minimize": "Свернуть",
+  "Context size / model limit": "Размер контекста / лимит модели",
+  "Context window (tokens)": "Окно контекста (токены)",
+  "Shown as used / total in the chat header. Leave empty to hide the limit.": "Показывается в шапке чата как использовано / всего. Пусто — лимит скрыт.",
+  "AI agent": "AI-агент",
+  "Take a look at the current document": "Посмотри текущий документ",
+  "AI agent is typing…": "AI-агент печатает…",
+  "{{name}} is typing…": "{{name}} печатает…",
+  "Send": "Отправить",
+  "Send when the agent finishes": "Отправить, когда агент закончит",
+  "Queue message": "Поставить в очередь",
+  "Remove queued message": "Убрать из очереди",
+  "Send now": "Отправить сейчас",
+  "Interrupt and send now": "Прервать и отправить сейчас",
+  "Stop": "Стоп",
+  "Response stopped.": "Ответ остановлен.",
+  "Connection lost — the answer was interrupted.": "Соединение потеряно — ответ был прерван.",
+  "Response stopped (manually or the connection dropped).": "Ответ остановлен (вручную или из-за разрыва соединения).",
+  "Chat menu": "Меню чата",
+  "No chats yet.": "Чатов пока нет.",
+  "Delete this chat?": "Удалить этот чат?",
+  "Ask the AI agent…": "Спросите AI-агента…",
+  "Ask the AI agent anything about your workspace.": "Спросите AI-агента о чём угодно по вашему рабочему пространству.",
+  "Failed to rename chat": "Не удалось переименовать чат",
+  "Failed to delete chat": "Не удалось удалить чат",
+  "Something went wrong": "Что-то пошло не так",
+  "AI chat is disabled for this workspace.": "AI-чат отключён для этого рабочего пространства.",
+  "The AI provider is not configured. Ask an administrator to set it up.": "AI-провайдер не настроен. Попросите администратора настроить его.",
+  "The AI agent could not respond. Please try again.": "AI-агент не смог ответить. Попробуйте ещё раз.",
+  "Searched pages": "Поиск по страницам",
+  "Read page": "Прочитана страница",
+  "Created page": "Создана страница",
+  "Updated page": "Обновлена страница",
+  "Renamed page": "Переименована страница",
+  "Moved page": "Перемещена страница",
+  "Deleted page (to trash)": "Удалена страница (в корзину)",
+  "Commented": "Добавлен комментарий",
+  "Resolved comment": "Комментарий решён",
+  "Ran tool {{name}}": "Выполнен инструмент {{name}}",
+  "AI agent «{{role}}» on behalf of {{person}}": "AI-агент «{{role}}» от имени {{person}}",
+  "AI agent {{name}}": "AI-агент {{name}}",
+  "Endpoints": "Эндпоинты",
+  "where we fetch models": "откуда мы получаем модели",
+  "All endpoints are OpenAI-compatible. Point the Base URL at OpenAI, OpenRouter, a local Ollama, or any self-hosted server.": "Все эндпоинты совместимы с OpenAI. Укажите в базовом URL адрес OpenAI, OpenRouter, локального Ollama или любого self-hosted сервера.",
+  "Chat / LLM": "Чат / LLM",
+  "root": "корневой",
+  "Semantic search": "Семантический поиск",
+  "Voice / STT": "Голос / STT",
+  "Voice dictation": "Голосовой ввод",
+  "Streaming dictation": "Потоковый голосовой ввод",
+  "Transcribe as you speak, cutting on pauses": "Транскрибирование по мере речи, с разбивкой на паузах",
+  "Voice dictation is not available yet.": "Голосовой ввод пока недоступен.",
+  "Test endpoint": "Проверить эндпоинт",
+  "Save and test": "Сохранить и проверить",
+  "Save endpoints": "Сохранить эндпоинты",
+  "Configured and enabled": "Настроено и включено",
+  "Configured but disabled": "Настроено, но отключено",
+  "Enabled but not configured": "Включено, но не настроено",
+  "Not configured": "Не настроено",
+  "External tools": "Внешние инструменты",
+  "Gitmost as MCP client": "Gitmost как MCP-клиент",
+  "Servers the agent calls out to.": "Серверы, к которым обращается агент.",
+  "MCP server": "MCP-сервер",
+  "expose the workspace": "открыть доступ к рабочему пространству",
+  "Enable MCP server": "Включить MCP-сервер",
+  "Exposes the workspace as an MCP server at /mcp — this provides a capability, it doesn't consume a model.": "Открывает рабочее пространство как MCP-сервер по адресу /mcp — это предоставляет возможность, а не потребляет модель.",
+  "Resolves to {{url}}": "Разрешается в {{url}}",
+  "Model": "Модель",
+  "Done": "Готово",
+  "shared prompt · safety framework appended automatically": "общий промпт · правила безопасности добавляются автоматически",
+  "/v1/chat/completions · root endpoint — Embeddings and Voice inherit its URL and key": "/v1/chat/completions · корневой эндпоинт — Эмбеддинги и Голос наследуют его URL и ключ",
+  "/v1/embeddings · embeds pages so semantic search can find them": "/v1/embeddings · создаёт эмбеддинги страниц, чтобы их находил семантический поиск",
+  "/v1/audio/transcriptions · works with local whisper (speaches / faster-whisper-server)": "/v1/audio/transcriptions · работает с локальным whisper (speaches / faster-whisper-server)",
+  "Vector search · requires pgvector": "Векторный поиск · требуется pgvector",
+  "Embedding API key": "API-ключ для эмбеддингов",
+  "Embeddings": "Эмбеддинги",
+  "Leave empty to use the chat API key": "Оставьте пустым, чтобы использовать API-ключ чата",
+  "Leave empty to use the chat base URL": "Оставьте пустым, чтобы использовать базовый URL чата",
+  "Reindex now": "Переиндексировать сейчас",
+  "Start dictation": "Начать диктовку",
+  "Stop recording": "Остановить запись",
+  "Transcribing…": "Транскрибация…",
+  "Microphone access denied": "Доступ к микрофону запрещён",
+  "No microphone found": "Микрофон не найден",
+  "Could not start recording": "Не удалось начать запись",
+  "Transcription failed": "Не удалось распознать речь",
+  "Transcribe": "Транскрибировать",
+  "No speech detected": "Речь не распознана",
+  "Voice dictation is not configured": "Голосовой ввод не настроен",
+  "Microphone is unavailable or already in use": "Микрофон недоступен или уже используется",
+  "Audio recording is not available in this browser/context": "Запись аудио недоступна в этом браузере/контексте",
+  "Dictation": "Диктовка",
+  "Dictation becomes available once the page finishes connecting": "Диктовка станет доступна после подключения к документу",
+  "No connection to the collaboration server — dictation unavailable": "Нет связи с сервером совместного редактирования — диктовка недоступна",
+  "This page is read-only": "Страница открыта только для чтения",
+  "Request format": "Формат запроса",
+  "How transcription requests are sent to the endpoint": "Как запросы на транскрибирование отправляются на эндпоинт",
+  "OpenAI-compatible (multipart/form-data)": "Совместимо с OpenAI (multipart/form-data)",
+  "OpenRouter (JSON, base64 audio)": "OpenRouter (JSON, аудио в base64)",
   "Dictation language": "Язык диктовки",
   "Auto-detect": "Автоопределение",
   "Spoken language hint sent to the transcription model. Auto-detect lets the model decide.": "Подсказка языка речи для модели транскрипции. «Автоопределение» оставляет выбор за моделью.",
+  "Agent role": "Роль агента",
+  "Universal assistant": "Универсальный ассистент",
+  "Add role": "Добавить роль",
+  "Edit role": "Изменить роль",
+  "Role name": "Название роли",
+  "e.g. Proofreader": "напр. Корректор",
+  "Optional. Shown as the chat badge.": "Необязательно. Отображается как значок чата.",
+  "Optional. A short note about what this role does.": "Необязательно. Краткое описание того, что делает эта роль.",
+  "Instructions": "Инструкции",
+  "The built-in safety framework is always added automatically.": "Встроенный набор правил безопасности всегда добавляется автоматически.",
+  "Model provider override": "Переопределение провайдера модели",
+  "Optional. Defaults to the workspace provider.": "Необязательно. По умолчанию используется провайдер рабочего пространства.",
+  "Model override": "Переопределение модели",
+  "Optional. Defaults to the workspace model.": "Необязательно. По умолчанию используется модель рабочего пространства.",
+  "e.g. gpt-4o-mini": "напр. gpt-4o-mini",
+  "If you choose a different provider, it must already be configured in AI settings.": "Если вы выбираете другого провайдера, он уже должен быть настроен в настройках ИИ.",
+  "Start automatically": "Запускать автоматически",
+  "When on, picking this role sends a launch message and starts the chat. When off, the role is selected and you type the first message yourself.": "Когда включено, выбор этой роли отправляет стартовое сообщение и начинает чат. Когда выключено, роль выбирается, а первое сообщение вы вводите сами.",
+  "Launch message": "Стартовое сообщение",
+  "Sent automatically when this role is picked. Leave empty to use the default text. Ignored when “Start automatically” is off.": "Отправляется автоматически при выборе этой роли. Оставьте пустым, чтобы использовать текст по умолчанию. Игнорируется, когда «Запускать автоматически» выключено.",
+  "Agent roles": "Роли агента",
+  "Reusable presets that shape the agent's behavior (and optionally its model). Picked when starting a new chat.": "Многоразовые пресеты, определяющие поведение агента (и, при желании, его модель). Выбираются при запуске нового чата.",
+  "No roles configured": "Роли не настроены",
+  "Delete role": "Удалить роль",
+  "Are you sure you want to delete this role?": "Вы уверены, что хотите удалить эту роль?",
+  "HTML embed": "HTML-вставка",
+  "Edit HTML embed": "Изменить HTML-вставку",
+  "HTML embed is disabled in this workspace": "HTML-вставки отключены в этом рабочем пространстве",
+  "Click to add HTML / CSS / JS": "Нажмите, чтобы добавить HTML / CSS / JS",
+  "This HTML/CSS/JS runs in a sandboxed frame and cannot access the viewer's session, cookies, or API.": "Этот HTML/CSS/JS выполняется в изолированном фрейме и не имеет доступа к сессии, cookie или API просматривающего.",
+  "<script>...</script>": "<script>...</script>",
+  "Height (px, blank = auto)": "Высота (px, пусто = авто)",
+  "advanced": "дополнительно",
+  "Enable HTML embed": "Включить HTML-вставки",
+  "Allow members to insert raw HTML/CSS/JavaScript blocks. The block renders in a sandboxed frame and cannot access the viewer's session, cookies, or API. Off by default.": "Разрешить участникам вставлять блоки с необработанным HTML/CSS/JavaScript. Блок отображается в изолированном фрейме и не имеет доступа к сессии, cookie или API просматривающего. По умолчанию выключено.",
+  "When enabled, any member can insert an HTML embed block. The toggle just enables or disables the block type workspace-wide.": "Когда включено, любой участник может вставить блок HTML-вставки. Переключатель просто включает или отключает этот тип блока во всём рабочем пространстве.",
+  "Embeds run inside a sandboxed iframe with a separate origin, so they cannot read or modify the page they are embedded in.": "Вставки выполняются в изолированном iframe с отдельным источником, поэтому они не могут читать или изменять страницу, в которую встроены.",
+  "Turning this off hides existing embeds (they render as a disabled placeholder) and stops serving them on public share pages.": "Отключение этой опции скрывает существующие вставки (они отображаются как отключённая заглушка) и прекращает их показ на публичных страницах.",
+  "Analytics / tracker": "Аналитика / трекер",
+  "Injected verbatim into the <head> of PUBLIC SHARE pages only (same-origin). For analytics snippets (Google Analytics, Yandex.Metrika, etc.). Admin only.": "Вставляется дословно в <head> только ПУБЛИЧНЫХ страниц (тот же источник). Для сниппетов аналитики (Google Analytics, Яндекс.Метрика и т. п.). Только для администраторов.",
+  "Go to login page": "Перейти на страницу входа",
+  "Move to space": "Переместить в пространство",
   "Float left (wrap text)": "Обтекание слева",
   "Float right (wrap text)": "Обтекание справа",
   "Inline (side by side)": "В ряд",
@@ -1199,6 +1354,7 @@
   "Showing {{count}} subpages_one": "Показано {{count}} подстраница",
   "Showing {{count}} subpages_few": "Показано {{count}} подстраницы",
   "Showing {{count}} subpages_many": "Показано {{count}} подстраниц",
+  "Showing {{count}} subpages_other": "Показано {{count}} подстраниц",
   "Protocol": "Протокол",
   "How chat requests are sent and how reasoning is surfaced": "Как отправляются запросы чата и как показывается reasoning",
   "OpenAI-compatible (surfaces reasoning)": "OpenAI-совместимый (показывает reasoning)",
@@ -1268,7 +1424,6 @@
   "Retry": "Повторить",
   "The catalog is empty": "Каталог пуст",
   "No role bundles are published for this language yet. Try switching the content language.": "Для этого языка ещё не опубликовано ни одного набора ролей. Попробуйте сменить язык контента.",
-  "No roles configured": "Роли не настроены",
   "Already up to date": "Уже актуальна",
   "Updated to the latest version": "Обновлено до последней версии",
   "This role is no longer in the catalog": "Эта роль больше не представлена в каталоге",
@@ -1281,5 +1436,29 @@
   "The commented text changed since this suggestion was made; it was not applied.": "Прокомментированный текст изменился после создания предложения; оно не было применено.",
   "Dismiss": "Не применять",
   "Suggestion dismissed": "Предложение отклонено",
-  "Failed to dismiss suggestion": "Не удалось отклонить предложение"
+  "Failed to dismiss suggestion": "Не удалось отклонить предложение",
+  "Save version": "Сохранить версию",
+  "Ctrl+S": "Ctrl+S",
+  "Version saved": "Версия сохранена",
+  "Already saved as the latest version": "Уже сохранено как последняя версия",
+  "Agent version": "Версия агента",
+  "Boundary": "Граница",
+  "Autosave": "Автосейв",
+  "Only versions": "Только версии",
+  "No saved versions yet.": "Пока нет сохранённых версий.",
+  "Time worked on this article": "Время работы над статьёй",
+  "Show time worked on this page": "Показать время работы над страницей",
+  "Estimated time worked (inactivity gap {{gap}} min)": "Оценка времени работы (порог паузы {{gap}} мин)",
+  "Estimate · timezone {{tz}} · inactivity gap {{gap}} min": "Оценка · таймзона {{tz}} · порог паузы {{gap}} мин",
+  "No editing activity recorded yet.": "Правок пока нет.",
+  "× {{count}} days without edits": "× {{count}} дн. без правок",
+  "agent: {{value}}": "агент: {{value}}",
+  "Work": "Работа",
+  "Agent": "Агент",
+  "≈ {{hours}}h {{minutes}}m": "≈ {{hours}} ч {{minutes}} мин",
+  "≈ {{hours}}h": "≈ {{hours}} ч",
+  "≈ {{minutes}}m": "≈ {{minutes}} мин",
+  "{{hours}}h {{minutes}}m": "{{hours}} ч {{minutes}} м",
+  "{{hours}}h": "{{hours}} ч",
+  "{{minutes}}m": "{{minutes}} м"
 }

apps/client/src/components/chunk-load-error-boundary.tsx

@@ -1,8 +1,11 @@
 import { ReactNode } from "react";
 import { ErrorBoundary } from "react-error-boundary";
 import { Button, Center, Stack, Text } from "@mantine/core";
-
-const RELOAD_FLAG = "chunk-reload-attempted";
+import {
+  hasAutoReloaded,
+  markAutoReloaded,
+  recordReloadBreadcrumb,
+} from "@/lib/reload-guard";
 
 // Heuristic detection of a failed dynamic import. Since the code-splitting work,
 // every route (plus Aside / AiChatWindow) is React.lazy: when a new deploy
@@ -21,20 +24,26 @@ export function isChunkLoadError(error: unknown): boolean {
   );
 }
 
-function handleError(error: unknown) {
+// Exported for tests: the reactive chunk-load reload decision, so the shared
+// window budget (invariant: ≤1 auto-reload per window across this path AND the
+// proactive version-coherence path) can be exercised against the real guard.
+export function handleError(error: unknown) {
   if (!isChunkLoadError(error)) return;
   // A stale-chunk 404 is cured by a full reload that re-fetches index.html and
-  // the new chunk manifest. Auto-reload once, guarding against a reload loop
-  // (e.g. a genuinely missing chunk) with a one-shot sessionStorage flag. If the
-  // flag is already set we fall through to the manual recovery UI below.
-  try {
-    if (sessionStorage.getItem(RELOAD_FLAG)) return;
-    sessionStorage.setItem(RELOAD_FLAG, "1");
-  } catch {
-    // sessionStorage unavailable (private mode / disabled): skip the automatic
-    // reload rather than risk an unguarded loop; the fallback UI still recovers.
-    return;
-  }
+  // the new chunk manifest. Auto-reload at most once per window via the SHARED
+  // window-based reload guard (see @/lib/reload-guard — the same budget the
+  // proactive version-coherence path consumes, so a mismatch that arrives on
+  // both paths reloads at most once per window across BOTH). This recovers
+  // across multiple deploys in a single tab's lifetime, yet a permanently-broken
+  // lazy chunk (which would loop) is stopped after the first reload and falls
+  // through to the manual recovery UI below. If the shared budget is already
+  // spent this window, or the stamp write fails (storage unavailable), we return
+  // without reloading rather than risk a loop.
+  if (hasAutoReloaded()) return;
+  if (!markAutoReloaded()) return;
+  // Trace before the reload clears the console (same diagnostic breadcrumb the
+  // proactive version-coherence path writes, tagged with this path).
+  recordReloadBreadcrumb({ path: "chunk-boundary" });
   window.location.reload();
 }
 

apps/client/src/features/ai-chat/components/ai-chat-window.tsx

@@ -58,8 +58,11 @@ import ConversationList from "@/features/ai-chat/components/conversation-list.ts
 import ChatThread from "@/features/ai-chat/components/chat-thread.tsx";
 import {
   exportAiChat,
+  getAiChatMessagesDelta,
   stopRun,
 } from "@/features/ai-chat/services/ai-chat-service.ts";
+import { mergeDeltaRowsIntoPages } from "@/features/ai-chat/utils/resume-helpers.ts";
+import type { IAiChatMessageRow } from "@/features/ai-chat/types/ai-chat.types.ts";
 import { useChatSession } from "@/features/ai-chat/hooks/use-chat-session.ts";
 import {
   shouldCollapseOnOutsidePointer,
@@ -86,19 +89,11 @@ const MIN_HEIGHT = 400;
 // Margin kept between the window and the viewport edges while dragging.
 const EDGE_MARGIN = 8;
 
-// #184 phase 1.5 / #430: backstop for the degraded-poll fallback. The poll is
-// armed when a resume attempt could not attach to the live run and disarmed by the
-// thread on settle / local stream; this cap is the ONLY backstop against an endless
-// tick (a stuck 'streaming' row before the boot-sweep, or a user-tail 204 with no
-// run).
-//
-// #430: measured from RUN ACTIVITY, not from arm-time. A real autonomous run takes
-// 11-25 min — longer than a fixed 10-min-from-start cap, which used to cut the poll
-// off mid-run. Instead we cap on INACTIVITY: keep polling as long as the run is
-// still making progress (its persisted rows keep changing), and only give up after
-// this long with NO new activity. A genuinely stuck run produces no row changes, so
-// the idle cap still bounds it; a long-but-progressing run polls to completion.
-const DEGRADED_POLL_IDLE_MAX_MS = 10 * 60_000;
+// #184 phase 1.5 / #430 / #488: the degraded-poll fallback. The window owns only
+// a DUMB 2.5s timer, gated by an armed flag; the THREAD's run-lifecycle FSM owns
+// arm/disarm AND the inactivity cap that turns a stuck run into a `stalled` banner
+// (#488 commit 4a — the cap moved into the thread so polling->stalled is a single
+// FSM transition; the window no longer silently stops polling at the cap).
 
 /** Compact token formatter: 1.2M / 3.4k / 950. */
 function formatTokens(n: number): string {
@@ -259,17 +254,13 @@ export default function AiChatWindow() {
     [roles],
   );
 
-  // #184 phase 1.5: degraded-poll fallback (replaces the F4/F5/F7 latches). When
-  // ChatThread could not attach to a still-running run it arms this via
-  // onResumeFallback(true); the thread disarms it on settle / local stream. The
-  // window only OWNS the timer (armedAtRef stamps when it was armed for the cap).
+  // #184 phase 1.5 / #488: degraded-poll fallback. ChatThread's FSM arms this via
+  // onResumeFallback(true) when it enters a poll-bearing recovery (attach 204 /
+  // starved finish / stop) and disarms it on settle / local stream / stalled. The
+  // window owns ONLY the dumb 2.5s timer; the THREAD owns arm/disarm AND the
+  // inactivity cap (a stuck run -> the thread's `stalled` banner disarms this).
   const [degradedPoll, setDegradedPoll] = useState(false);
-  // #430: timestamp of the LAST run activity while the poll is armed — stamped on
-  // arm and re-stamped whenever the polled rows change (see the effect below). The
-  // idle cap is measured from this, so a long-but-progressing run keeps polling.
-  const lastActivityAtRef = useRef(0);
   const onResumeFallback = useCallback((active: boolean): void => {
-    if (active) lastActivityAtRef.current = Date.now();
     setDegradedPoll(active);
   }, []);
   // Reset the degraded poll whenever the open chat changes: it is scoped to the
@@ -281,32 +272,63 @@ export default function AiChatWindow() {
   const { data: messageRows, isLoading: messagesLoading } =
     useAiChatMessagesQuery(
       activeChatId ?? undefined,
-      // DELIBERATELY DUMB (invariant 8 / task 2.4): poll every 2.5s while armed
-      // and while the run is still active (#430: under the INACTIVITY cap, not a
-      // fixed-from-start cap); otherwise off. NO error checks (TanStack v5 resets
-      // fetchFailureCount each fetch, so consecutive errors are not expressible —
-      // and the poll must survive a server restart) and NO tail checks (the
-      // settled/local-stream semantics live in ChatThread, which disarms via
-      // onResumeFallback(false)). The idle cap is the only backstop.
-      () =>
-        degradedPoll === true &&
-        Date.now() - lastActivityAtRef.current < DEGRADED_POLL_IDLE_MAX_MS
-          ? 2500
-          : false,
-      // #344: gate on windowOpen too — no message history is fetched (and no
-      // degraded poll runs) while the window is closed; it loads when the window
-      // opens with an active chat.
+      // #491: the full infinite-query no longer POLLS. It seeds the thread ONCE; the
+      // degraded fallback now runs a DELTA poller (below) that augments THIS cache
+      // idempotently, instead of refetching every page (with full parts) every 2.5s.
+      false,
+      // #344: gate on windowOpen too — no message history is fetched while the window
+      // is closed; it loads when the window opens with an active chat.
       windowOpen,
     );
 
-  // #430: re-stamp the activity clock whenever the polled rows change while the
-  // poll is armed. TanStack keeps the same `messageRows` reference across refetches
-  // that return deep-equal data (structural sharing), so a new reference means the
-  // run genuinely progressed — which extends the inactivity cap above. A stuck run
-  // yields no reference change, so the cap eventually fires and stops the poll.
+  // #491 degraded DELTA poll. While armed (degradedPoll) and the window is open on a
+  // chat, poll POST /ai-chat/messages/delta every 2.5s: it returns only the rows
+  // CHANGED since the previous cursor (+ the run fact) in ONE round-trip. We merge
+  // those rows into the SAME infinite-query cache the thread reads (idempotently by
+  // id — the delta's overlap window re-delivers rows), so the thread's reconcile
+  // effect follows the detached run to its terminal row from a fraction of the wire
+  // cost. The run-fact settle stays the thread FSM's job (row-status reconcile), so
+  // we do NOT double-poll /run here. Cursor resets when the chat changes / disarms.
+  const deltaCursorRef = useRef<string | undefined>(undefined);
   useEffect(() => {
-    if (degradedPoll) lastActivityAtRef.current = Date.now();
-  }, [degradedPoll, messageRows]);
+    deltaCursorRef.current = undefined;
+  }, [activeChatId, degradedPoll]);
+  useEffect(() => {
+    if (!degradedPoll || !windowOpen || !activeChatId) return;
+    const chatId = activeChatId;
+    let cancelled = false;
+    const tick = async (): Promise<void> => {
+      try {
+        const res = await getAiChatMessagesDelta(chatId, deltaCursorRef.current);
+        if (cancelled) return;
+        deltaCursorRef.current = res.cursor;
+        if (res.rows.length > 0) {
+          queryClient.setQueryData(
+            AI_CHAT_MESSAGES_RQ_KEY(chatId),
+            (
+              old:
+                | {
+                    pages: { items: IAiChatMessageRow[]; meta: unknown }[];
+                    pageParams: unknown[];
+                  }
+                | undefined,
+            ) =>
+              old
+                ? { ...old, pages: mergeDeltaRowsIntoPages(old.pages, res.rows) }
+                : old,
+          );
+        }
+      } catch {
+        // Transient failure (e.g. a server restart mid-run): swallow and retry on
+        // the next tick — the poll must survive a bounce, like the old dumb refetch.
+      }
+    };
+    const id = setInterval(() => void tick(), 2500);
+    return () => {
+      cancelled = true;
+      clearInterval(id);
+    };
+  }, [degradedPoll, windowOpen, activeChatId, queryClient]);
 
   // #184 reconnect-and-live-follow. Whether detached agent runs are enabled for
   // this workspace. When the feature is off no runs are ever created, so the

apps/client/src/features/ai-chat/components/ai-chat.module.css

@@ -55,6 +55,15 @@
     padding-inline-start: 1.4em;
 }
 
+/* The canonical converter renders list items through the editor schema, which
+   wraps each item's content in a <p> (listItem content is `paragraph+`). Drop
+   that paragraph's block margin so list items render TIGHT (no extra vertical
+   gap), matching the previous marked output — same rule already applied to
+   table cells above (issue #347). */
+.markdown li p {
+    margin: 0;
+}
+
 /* GFM tables in assistant markdown. The chat lives in a NARROW side panel, so a
    wide LLM table must scroll horizontally instead of collapsing its columns:
    `.markdown` sets `word-break: break-word`, which (with the default table
@@ -172,6 +181,14 @@
     margin: 0 0 4px;
 }
 
+/* Same as `.markdown li p` above: the canonical converter wraps every list
+   item's content in a <p>, so without this each reasoning-panel list item would
+   pick up `.reasoningText p`'s 4px bottom margin and render too loose. Drop it
+   so Reasoning-panel lists stay tight, mirroring the pre-#347 marked output. */
+.reasoningText li p {
+    margin: 0;
+}
+
 .inputWrapper {
     flex: 0 0 auto;
     padding-top: var(--mantine-spacing-xs);

apps/client/src/features/ai-chat/components/message-item-memo.test.tsx

@@ -27,6 +27,7 @@ vi.mock("@/features/ai-chat/utils/markdown.ts", async () => {
 
 import MessageItem from "./message-item";
 import { messageSignature } from "@/features/ai-chat/utils/message-signature.ts";
+import { splitPlainChunks } from "./streaming-plain-text";
 
 // matchMedia (read by MantineProvider) is stubbed globally in vitest.setup.ts.
 
@@ -114,3 +115,89 @@ describe("MessageItem markdown memoization", () => {
     expect(queryByText("streamed answer")).not.toBeNull();
   });
 });
+
+// PERF SMOKE (#492): the whole point of the incremental streaming render is that
+// the ANSWER path costs O(number of markdown blocks), NOT O(number of throttled
+// ~20Hz ticks). Pre-#492 the finalized MarkdownPart re-parsed the WHOLE growing
+// answer on every delta — a synthetic ~100 KB stream measured 394 renderChatMarkdown
+// calls (one per tick). With the incremental render each STABILIZED block is parsed
+// exactly once (memoized in MarkdownChunk) and the live tail is cheap plain text, so
+// the call count collapses to ~= the block count regardless of tick granularity.
+describe("MessageItem streaming answer render is O(blocks), not O(ticks)", () => {
+  // ~100 KB answer. Each section is a heading + a paragraph — TWO blank-line
+  // delimited markdown blocks — so the safe-cut block count is ~2× the section
+  // count. The perf claim is about the BLOCK count (the memoization granularity),
+  // measured directly with splitPlainChunks below, not the section count.
+  const buildAnswer = () => {
+    const SECTIONS = 100;
+    const paragraphs: string[] = [];
+    for (let i = 0; i < SECTIONS; i++) {
+      paragraphs.push(`## Section ${i}\n\n` + "lorem ipsum dolor ".repeat(55));
+    }
+    const full = paragraphs.join("\n\n");
+    // The number of memoized markdown blocks the incremental render splits into
+    // (all but the live tail are parsed once each).
+    return { full, blocks: splitPlainChunks(full).length };
+  };
+
+  const streamMsg = (text: string, state: "streaming" | "done"): UIMessage =>
+    ({
+      id: "m1",
+      role: "assistant",
+      parts: [{ type: "text", text, state }],
+    }) as UIMessage;
+
+  it("parses each block ~once over a 100KB stream (≈blocks, ≪ ticks)", () => {
+    renderChatMarkdownSpy.mockClear();
+    const { full, blocks } = buildAnswer();
+    const CHUNK = 128; // a realistic ~20Hz throttled delta size
+    const ticks = Math.ceil(full.length / CHUNK);
+
+    let msg = streamMsg(full.slice(0, CHUNK), "streaming");
+    const { rerender } = render(
+      <MantineProvider>
+        <MessageItem
+          message={msg}
+          signature={messageSignature(msg)}
+          turnStreaming
+        />
+      </MantineProvider>,
+    );
+    for (let end = 2 * CHUNK; end < full.length; end += CHUNK) {
+      msg = streamMsg(full.slice(0, end), "streaming");
+      rerender(
+        <MantineProvider>
+          <MessageItem
+            message={msg}
+            signature={messageSignature(msg)}
+            turnStreaming
+          />
+        </MantineProvider>,
+      );
+    }
+    // Finalize: the streaming→done flip renders the whole answer through ONE
+    // canonical pass (visual parity), so the finished DOM matches the pre-#492
+    // output. This is the single extra parse on top of the per-block ones.
+    const done = streamMsg(full, "done");
+    rerender(
+      <MantineProvider>
+        <MessageItem message={done} signature={messageSignature(done)} />
+      </MantineProvider>,
+    );
+
+    const calls = renderChatMarkdownSpy.mock.calls.length;
+    // Sanity: the stream really had far more ticks than blocks (else the test is
+    // vacuous — the point is that calls scale with blocks, not ticks).
+    expect(ticks).toBeGreaterThan(blocks * 3);
+    // O(blocks): each stabilized block parsed once + the single final whole-text
+    // parse. A small constant absorbs the finalize render and the live-tail block;
+    // the load-bearing claim is the bound below.
+    expect(calls).toBeLessThanOrEqual(blocks + 2);
+    // ≪ ticks — and, non-vacuously, the blocks WERE parsed (not skipped entirely).
+    expect(calls).toBeLessThan(ticks / 3);
+    expect(calls).toBeGreaterThan(blocks / 2);
+    // MUTATION-VERIFY (documented, not run here): dropping the `memo()` wrapper on
+    // MarkdownChunk (so every stable block re-parses each tick) drives `calls`
+    // toward `ticks` (~394), reddening both upper-bound assertions above.
+  });
+});

apps/client/src/features/ai-chat/components/message-item.render.test.tsx

@@ -0,0 +1,112 @@
+import { describe, expect, it, vi } from "vitest";
+import { render } from "@testing-library/react";
+import { MantineProvider } from "@mantine/core";
+import type { UIMessage } from "@ai-sdk/react";
+
+// Stub react-i18next (the component reads `useTranslation`). Mirrors the other
+// message-item specs.
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (key: string) => key }),
+}));
+
+import MessageItem from "./message-item";
+import { messageSignature } from "@/features/ai-chat/utils/message-signature.ts";
+// The REAL canonical renderer (NOT the spy the memo test installs): this file
+// exercises the actual markdown output so the visual-regression assertions below
+// compare against genuine HTML (incl. the schema's `<li><p>` wrappers).
+import { renderChatMarkdown } from "@/features/ai-chat/utils/markdown.ts";
+import classes from "./ai-chat.module.css";
+
+const msg = (
+  parts: UIMessage["parts"],
+  extra?: Partial<UIMessage>,
+): UIMessage =>
+  ({ id: "m1", role: "assistant", parts, ...extra }) as UIMessage;
+
+const renderRow = (message: UIMessage, turnStreaming = false) =>
+  render(
+    <MantineProvider>
+      <MessageItem
+        message={message}
+        signature={messageSignature(message)}
+        turnStreaming={turnStreaming}
+      />
+    </MantineProvider>,
+  );
+
+// A rich multi-block answer that exercises headings, a list (the `<li><p>` case
+// the scoped CSS tightens), inline emphasis, and multiple paragraphs.
+const ANSWER = [
+  "# Заголовок",
+  "",
+  "Первый абзац с **жирным** и `кодом`.",
+  "",
+  "- пункт один",
+  "- пункт два",
+  "",
+  "Второй абзац.",
+].join("\n");
+
+describe("MessageItem final render — visual parity with the canonical pipeline", () => {
+  it("a finalized text part renders exactly renderChatMarkdown(text)", () => {
+    const { container } = renderRow(
+      msg([{ type: "text", text: ANSWER, state: "done" }]),
+    );
+    const block = container.querySelector(`.${classes.markdown}`);
+    expect(block).not.toBeNull();
+    // Byte-for-byte the canonical output (the SAME whole-text pass the pre-#492
+    // MarkdownPart produced), including `<li><p>…</p></li>` wrappers.
+    expect(block!.innerHTML).toBe(renderChatMarkdown(ANSWER, {}));
+    // The list wrapper is really present (guards against a vacuous empty render).
+    expect(container.querySelectorAll("li p").length).toBe(2);
+  });
+
+  it("the streaming incremental view CONVERGES to the canonical render on finish", () => {
+    // Mount mid-stream (live tail) — the DOM here is the incremental view.
+    const { container, rerender } = render(
+      <MantineProvider>
+        <MessageItem
+          message={msg([{ type: "text", text: ANSWER, state: "streaming" }])}
+          signature={messageSignature(
+            msg([{ type: "text", text: ANSWER, state: "streaming" }]),
+          )}
+          turnStreaming
+        />
+      </MantineProvider>,
+    );
+    // Finish the turn: state flips to done AND the turn is no longer streaming.
+    const done = msg([{ type: "text", text: ANSWER, state: "done" }]);
+    rerender(
+      <MantineProvider>
+        <MessageItem message={done} signature={messageSignature(done)} />
+      </MantineProvider>,
+    );
+    // After finish there is exactly ONE canonical markdown container whose HTML is
+    // the whole-text render — identical to the non-streaming path above.
+    const blocks = container.querySelectorAll(`.${classes.markdown}`);
+    expect(blocks.length).toBe(1);
+    expect(blocks[0].innerHTML).toBe(renderChatMarkdown(ANSWER, {}));
+  });
+
+  it("neutralizeInternalLinks is honored on the finalized render", () => {
+    const linkAnswer = "См. [страницу](/p/abc).";
+    const { container } = render(
+      <MantineProvider>
+        <MessageItem
+          message={msg([{ type: "text", text: linkAnswer, state: "done" }])}
+          signature={messageSignature(
+            msg([{ type: "text", text: linkAnswer, state: "done" }]),
+          )}
+          neutralizeInternalLinks
+        />
+      </MantineProvider>,
+    );
+    const block = container.querySelector(`.${classes.markdown}`);
+    expect(block!.innerHTML).toBe(
+      renderChatMarkdown(linkAnswer, { neutralizeInternalLinks: true }),
+    );
+    // The internal link was made inert (no href) by the neutralization flag.
+    const a = container.querySelector("a");
+    expect(a?.hasAttribute("href")).toBe(false);
+  });
+});

apps/client/src/features/ai-chat/components/message-item.tsx

@@ -4,6 +4,7 @@ import { useTranslation } from "react-i18next";
 import type { UIMessage } from "@ai-sdk/react";
 import ToolCallCard from "@/features/ai-chat/components/tool-call-card.tsx";
 import ReasoningBlock from "@/features/ai-chat/components/reasoning-block.tsx";
+import { StreamingMarkdownText } from "@/features/ai-chat/components/streaming-markdown-text.tsx";
 import ChatErrorAlert from "@/features/ai-chat/components/chat-error-alert.tsx";
 import ChatStoppedNotice from "@/features/ai-chat/components/chat-stopped-notice.tsx";
 import { ToolUiPart, isToolPart } from "@/features/ai-chat/utils/tool-parts.tsx";
@@ -47,6 +48,13 @@ interface MessageItemProps {
    * agent's raw query/argument text.
    */
   showInput?: boolean;
+  /**
+   * Forwarded to ToolCallCard: whether a failed tool card renders its raw
+   * errorText. Defaults to true (internal chat). The public share passes false so
+   * internal detail in a tool error is never painted (belt to the server-side
+   * byte sanitization).
+   */
+  showErrors?: boolean;
   /**
    * Neutralize internal/relative markdown links in the rendered answer (drop
    * their href so they become inert text). Defaults to false (internal chat,
@@ -79,17 +87,39 @@ interface MessageItemProps {
  * One assistant text part rendered as sanitized markdown. Memoized on its inputs
  * so a finalized text part is NOT re-parsed on every streamed delta: during a
  * turn only the actively-growing tail part changes its `text`, so every earlier
- * part hits the memo and skips the expensive marked + DOMPurify pass. Props are
- * primitives, so React.memo's default shallow compare is exactly right (the
- * `text` string is compared by value).
+ * part hits the memo and skips the expensive canonical parse + DOMPurify pass.
+ * Props are primitives, so React.memo's default shallow compare is exactly right
+ * (the `text` string is compared by value).
+ *
+ * Streaming gate (#492) — mirrors ReasoningBlock:
+ *  - `streaming` (this is the live, actively-growing tail part of an in-flight
+ *    turn): render incrementally via StreamingMarkdownText — the stabilized blocks
+ *    go through the canonical pipeline (each parsed ONCE, memoized) and only the
+ *    live tail is cheap plain text. This makes the per-tick cost O(new blocks),
+ *    not the pre-#492 O(ticks) whole-answer re-parse on every ~20Hz delta.
+ *  - finalized (the common case, and the turn-end flip): render the WHOLE text
+ *    through ONE canonical pass — byte-identical to the pre-#492 output (visual
+ *    parity). The row re-renders on the streaming→done flip because
+ *    `messageSignature` tracks each part's `state` (and `turnStreaming` flips at
+ *    turn end), so the incremental view always converges to this single render.
  */
 const MarkdownPart = memo(function MarkdownPart({
   text,
   neutralizeInternalLinks,
+  streaming,
 }: {
   text: string;
   neutralizeInternalLinks: boolean;
+  streaming: boolean;
 }) {
+  if (streaming) {
+    return (
+      <StreamingMarkdownText
+        text={text}
+        neutralizeInternalLinks={neutralizeInternalLinks}
+      />
+    );
+  }
   const html = renderChatMarkdown(text, { neutralizeInternalLinks });
   if (html) {
     return (
@@ -125,6 +155,7 @@ function MessageItem({
   message,
   showCitations = true,
   showInput = true,
+  showErrors = true,
   neutralizeInternalLinks = false,
   assistantName,
   turnStreaming = false,
@@ -171,47 +202,10 @@ function MessageItem({
         {resolveAssistantName(assistantName) ?? t("AI agent")}
       </Text>
       {message.parts.map((part, index) => {
-        if (part.type === "reasoning") {
-          // Reasoning ("thinking") -> a collapsible block with its own token
-          // count. Empty/whitespace reasoning with no authoritative count carries
-          // nothing to show, so skip it (avoids an empty 0-token block).
-          const text = (part as { text?: string }).text ?? "";
-          if (!text.trim() && !(reasoningTokens && reasoningTokens > 0))
-            return null;
-          // Absent state (persisted rows) and "done" both mean finalized.
-          // `messageSignature` already includes each part's `state`, so the
-          // streaming→done flip changes the row signature and re-renders this
-          // row — which is what lets ReasoningBlock switch from chunked plain
-          // text to its one-time markdown parse (see reasoning-block.tsx).
-          // ALSO require the turn to be live: a part stranded at
-          // `state:"streaming"` after the turn ended (no `reasoning-end` — see
-          // the `turnStreaming` prop doc) must still finalize and parse.
-          const streaming =
-            turnStreaming && (part as { state?: string }).state === "streaming";
-          return (
-            <ReasoningBlock
-              key={index}
-              text={text}
-              tokens={reasoningTokens}
-              streaming={streaming}
-            />
-          );
-        }
-
-        if (part.type === "text") {
-          // Skip empty/whitespace-only text parts (a streaming message often
-          // starts with an empty text part before the first token arrives); the
-          // typing indicator covers that gap until real content streams in.
-          if (!part.text.trim()) return null;
-          return (
-            <MarkdownPart
-              key={index}
-              text={part.text}
-              neutralizeInternalLinks={neutralizeInternalLinks}
-            />
-          );
-        }
-
+        // Tool parts (`tool-*` / `dynamic-tool`) are template-literal kinds, so
+        // they cannot be a `switch` case; the runtime guard handles them, and the
+        // switch below covers every CLOSED (literal-typed) part kind with a
+        // compile-time exhaustiveness check in its default.
         if (isToolPart(part.type)) {
           return (
             <ToolCallCard
@@ -219,11 +213,81 @@ function MessageItem({
               part={part as unknown as ToolUiPart}
               showCitations={showCitations}
               showInput={showInput}
+              showErrors={showErrors}
             />
           );
         }
 
-        return null;
+        switch (part.type) {
+          case "reasoning": {
+            // Reasoning ("thinking") -> a collapsible block with its own token
+            // count. Empty/whitespace reasoning with no authoritative count
+            // carries nothing to show, so skip it (avoids an empty 0-token block).
+            const text = part.text ?? "";
+            if (!text.trim() && !(reasoningTokens && reasoningTokens > 0))
+              return null;
+            // Absent state (persisted rows) and "done" both mean finalized.
+            // `messageSignature` already includes each part's `state`, so the
+            // streaming→done flip changes the row signature and re-renders this
+            // row — which is what lets ReasoningBlock switch from chunked plain
+            // text to its one-time markdown parse (see reasoning-block.tsx).
+            // ALSO require the turn to be live: a part stranded at
+            // `state:"streaming"` after the turn ended (no `reasoning-end` — see
+            // the `turnStreaming` prop doc) must still finalize and parse.
+            const streaming = turnStreaming && part.state === "streaming";
+            return (
+              <ReasoningBlock
+                key={index}
+                text={text}
+                tokens={reasoningTokens}
+                streaming={streaming}
+              />
+            );
+          }
+
+          case "text": {
+            // Skip empty/whitespace-only text parts (a streaming message often
+            // starts with an empty text part before the first token arrives); the
+            // typing indicator covers that gap until real content streams in.
+            if (!part.text.trim()) return null;
+            // The live, actively-growing tail part of the in-flight turn renders
+            // incrementally (see MarkdownPart); a finalized part (persisted, or
+            // the turn-end flip) renders the whole text through one canonical
+            // pass. Same liveness rule as the reasoning branch above.
+            const streaming = turnStreaming && part.state === "streaming";
+            return (
+              <MarkdownPart
+                key={index}
+                text={part.text}
+                neutralizeInternalLinks={neutralizeInternalLinks}
+                streaming={streaming}
+              />
+            );
+          }
+
+          case "source-url":
+          case "source-document":
+          case "file":
+          case "step-start":
+            // Not surfaced in the chat bubble (v1) — same as the pre-#492 default.
+            return null;
+
+          default: {
+            // Compile-time exhaustiveness over the CLOSED union members: every
+            // literal-typed part kind is handled above, so the only kinds that
+            // can reach here are the OPEN template-literal ones (`tool-*` — caught
+            // by the guard at runtime — and `data-*`) plus `dynamic-tool`. Adding
+            // a NEW closed part kind to UIMessagePart makes this assignment fail
+            // to compile, forcing it to be handled instead of silently ignored
+            // (this replaces the pre-#492 fall-through `return null` + WARNING).
+            const _exhaustive:
+              | `tool-${string}`
+              | "dynamic-tool"
+              | `data-${string}` = part.type;
+            void _exhaustive;
+            return null;
+          }
+        }
       })}
       {/* A persisted turn error (server stored it in metadata.error). Rendered
           here so it survives a thread remount and shows in reopened history. */}
@@ -284,6 +348,7 @@ export function arePropsEqual(
     prev.signature === next.signature &&
     prev.showCitations === next.showCitations &&
     prev.showInput === next.showInput &&
+    prev.showErrors === next.showErrors &&
     prev.neutralizeInternalLinks === next.neutralizeInternalLinks &&
     prev.assistantName === next.assistantName &&
     // The turn-end flip re-renders every row once (cheap, terminal event) —

apps/client/src/features/ai-chat/components/message-list.tsx

@@ -32,6 +32,12 @@ interface MessageListProps {
    * doesn't see the agent's raw query/argument text.
    */
   showInput?: boolean;
+  /**
+   * Forwarded to MessageItem -> ToolCallCard: whether a failed tool card renders
+   * its raw errorText. Defaults to true (internal chat). The public share passes
+   * false so internal detail in a tool error is never painted.
+   */
+  showErrors?: boolean;
   /**
    * Forwarded to MessageItem: neutralize internal/relative markdown links in
    * the rendered answers (drop their href so they render as inert text).
@@ -127,6 +133,7 @@ export default function MessageList({
   emptyState,
   showCitations = true,
   showInput = true,
+  showErrors = true,
   neutralizeInternalLinks = false,
   assistantName,
 }: MessageListProps) {
@@ -217,6 +224,7 @@ export default function MessageList({
             signature={messageSignature(message)}
             showCitations={showCitations}
             showInput={showInput}
+            showErrors={showErrors}
             neutralizeInternalLinks={neutralizeInternalLinks}
             assistantName={assistantName}
             // Turn-level liveness, gated to the TAIL row: only the tail message

apps/client/src/features/ai-chat/components/streaming-markdown-text.tsx

@@ -0,0 +1,96 @@
+import { memo, useMemo } from "react";
+import { splitPlainChunks } from "@/features/ai-chat/components/streaming-plain-text.tsx";
+import { renderChatMarkdown } from "@/features/ai-chat/utils/markdown.ts";
+import classes from "@/features/ai-chat/components/ai-chat.module.css";
+
+/**
+ * One STABILIZED markdown block, rendered through the canonical pipeline and
+ * memoized on its string prop. During streaming only the TAIL chunk grows (the
+ * `splitPlainChunks` append-only invariant guarantees every earlier chunk is
+ * byte-identical across deltas), so React skips every stable block and each one
+ * is parsed by `renderChatMarkdown` EXACTLY ONCE — turning the pre-#492
+ * "re-parse the whole accumulated answer on every ~20Hz tick" (O(ticks)) into
+ * O(number of blocks). The markup is DOMPurify-sanitized inside renderChatMarkdown
+ * before it reaches `dangerouslySetInnerHTML`.
+ *
+ * NOTE (transient streaming-only artifact): a safe cut is a blank-line boundary,
+ * so a construct that legitimately contains a blank line (e.g. a fenced code block
+ * with an empty line) can be split across chunks and render oddly WHILE it is still
+ * streaming. This is cosmetic and self-heals: the moment the part finalizes,
+ * MarkdownPart renders the WHOLE text through one canonical pass (visual parity
+ * with the pre-#492 output). The reasoning path makes the same trade (plain text
+ * while streaming, one markdown parse at the end).
+ */
+const MarkdownChunk = memo(function MarkdownChunk({
+  text,
+  neutralizeInternalLinks,
+}: {
+  text: string;
+  neutralizeInternalLinks: boolean;
+}) {
+  const html = renderChatMarkdown(text, { neutralizeInternalLinks });
+  if (html) {
+    return (
+      <div
+        className={classes.markdown}
+        // Sanitized by renderChatMarkdown (DOMPurify) before insertion.
+        dangerouslySetInnerHTML={{ __html: html }}
+      />
+    );
+  }
+  // Malformed/unsupported markdown could not render synchronously: raw text.
+  return (
+    <div className={classes.markdown} style={{ whiteSpace: "pre-wrap" }}>
+      {text}
+    </div>
+  );
+});
+
+/**
+ * The cheap streaming-time stand-in for the finalized answer's one-time markdown
+ * parse (see MarkdownPart in message-item.tsx). Mirrors StreamingPlainText's
+ * chunked-memo pattern but renders the STABILIZED prefix as real markdown (each
+ * block parsed once, memoized) and only the LIVE tail as flat plain text — so the
+ * user sees formatted output for everything up to the last safe cut, and the not-
+ * yet-stable tail (which markdown-parsing every tick would make O(ticks)) stays a
+ * single cheap escaped text node until it stabilizes into a new block.
+ *
+ * `splitPlainChunks` yields chunks where, under append-only growth, every chunk
+ * except the LAST is immutable; the last chunk is the live tail. Index keys are
+ * therefore stable (a given index never changes to a different chunk's content).
+ */
+export function StreamingMarkdownText({
+  text,
+  neutralizeInternalLinks,
+}: {
+  text: string;
+  neutralizeInternalLinks: boolean;
+}) {
+  const chunks = useMemo(() => splitPlainChunks(text), [text]);
+  return (
+    <>
+      {chunks.map((chunk, index) =>
+        index < chunks.length - 1 ? (
+          <MarkdownChunk
+            key={index}
+            text={chunk}
+            neutralizeInternalLinks={neutralizeInternalLinks}
+          />
+        ) : (
+          // The live tail: flat, React-escaped plain text (no markdown parse, no
+          // sanitizer, no innerHTML). `pre-wrap` preserves its newlines; trailing
+          // separator newlines are dropped at display time so the block gap comes
+          // from the markdown margins, not a doubled empty line (mirrors
+          // PlainChunk in streaming-plain-text.tsx).
+          <div
+            key={index}
+            className={classes.markdown}
+            style={{ whiteSpace: "pre-wrap" }}
+          >
+            {chunk.replace(/\n+$/, "")}
+          </div>
+        ),
+      )}
+    </>
+  );
+}

apps/client/src/features/ai-chat/components/tool-call-card.tsx

@@ -30,6 +30,16 @@ interface ToolCallCardProps {
    * the extra summary line, leaving the card (the action log) intact.
    */
   showInput?: boolean;
+  /**
+   * Whether to render the tool's raw errorText on a failed call. Defaults to true
+   * (the internal chat, where the operator may debug). The public share passes
+   * false: a tool error string can carry internal detail (an internal page title,
+   * a stack fragment, a provider message). This is the RENDER gate only — the
+   * authoritative fix also sanitizes the bytes server-side (see
+   * PublicShareChatToolsService.forShare), so a share reader never receives raw
+   * error text over the wire, not just never sees it painted (#394).
+   */
+  showErrors?: boolean;
 }
 
 /**
@@ -41,6 +51,7 @@ export default function ToolCallCard({
   part,
   showCitations = true,
   showInput = true,
+  showErrors = true,
 }: ToolCallCardProps) {
   const { t } = useTranslation();
   const toolName = getToolName(part);
@@ -74,7 +85,7 @@ export default function ToolCallCard({
         </Text>
       )}
 
-      {state === "error" && part.errorText && (
+      {state === "error" && showErrors && part.errorText && (
         <Text size="xs" c="red" mt={2}>
           {part.errorText}
         </Text>

apps/client/src/features/ai-chat/services/ai-chat-service.ts

@@ -57,6 +57,50 @@ export async function stopRun(
   return req.data;
 }
 
+/**
+ * Delta poll (#491): the chat's message rows changed since `cursor` (a DB-clock
+ * timestamp echoed from the previous poll) plus the current run fact, in ONE
+ * round-trip — the degraded-poll fallback's payload, replacing the old "refetch
+ * ALL infinite-query pages every 2.5s with full parts" poll. Omit `cursor` on the
+ * first poll (returns just a fresh cursor, no rows, to start the chain). The
+ * overlap window guarantees occasional REPEATS, so the caller MUST merge rows
+ * idempotently by id (mergeById). Owner-gated server-side.
+ */
+export async function getAiChatMessagesDelta(
+  chatId: string,
+  cursor?: string,
+): Promise<{
+  rows: IAiChatMessageRow[];
+  cursor: string;
+  run: { id: string; status: string } | null;
+}> {
+  const req = await api.post<{
+    rows: IAiChatMessageRow[];
+    cursor: string;
+    run: { id: string; status: string } | null;
+  }>("/ai-chat/messages/delta", { chatId, cursor });
+  return req.data;
+}
+
+/**
+ * #488: the run-fact — "is a run active on this chat?" — first-class from the
+ * server (POST /ai-chat/run). Called on mount to seed the client FSM's run-fact
+ * and to VERIFY after a supersede mismatch (an observer following a superseded
+ * run asks for the latest run and follows it). Returns the latest run row (with
+ * its `id` and `status`) and its projected assistant message, or `run: null` when
+ * the chat has never had a run. Owner-gated server-side.
+ */
+export async function getRun(chatId: string): Promise<{
+  run: { id: string; status: string } | null;
+  message: IAiChatMessageRow | null;
+}> {
+  const req = await api.post<{
+    run: { id: string; status: string } | null;
+    message: IAiChatMessageRow | null;
+  }>("/ai-chat/run", { chatId });
+  return req.data;
+}
+
 /**
  * Resolve the chat bound to a document (the current user's most-recent chat
  * created on that page), or null when there is none. Drives auto-open-on-page.

apps/client/src/features/ai-chat/state/run-fsm.spec.md

@@ -0,0 +1,190 @@
+# AI-chat run-lifecycle FSM — design spec (#488)
+
+This is the written design that `run-fsm.ts` implements. It ships in the PR (issue
+#488 commit 1: "the spec is written FIRST and enters the PR"). It has four parts:
+(1) the event × state transition table, (2) the map of every `chat-thread.tsx` ref
+to {FSM state | FSM context | stays data}, (3) the run-fact protocol, (4) the
+invariants.
+
+The reducer is a **pure function** `reduce(machine, event) → machine`. The returned
+machine carries the **command effects** for that transition; a thin runtime in
+`chat-thread.tsx` dispatches events and executes effects. Because it is pure, the
+whole machine is enumerable and unit-tested directly (event × state → next state is
+the observable property) — see `run-fsm.test.ts`.
+
+---
+
+## 1. Event × state transition table
+
+Phases: `idle | sending | streaming | attaching | reconnecting(attempt,failed) |
+polling(reason) | stalled | stopping | superseding | error(kind)`.
+Context (orthogonal): `epoch`, `ownership: local|observer`, `runFact: {runId}|null`,
+`liveFollow` (are we following a live run we locally streamed — the reconnect
+ladder — vs a one-shot mount-attach resume? both are `observer`, but a live-follow
+drop RE-ENTERS the ladder (#488 commit 3) while a mount-resume drop polls).
+
+Legend: **†** = command-transition (bumps `epoch`, I1). Effects in `[…]`.
+
+| Event (source) | From phase(s) | → To phase | Effects / ctx |
+|---|---|---|---|
+| `SEND_LOCAL` (user send) | idle, error, polling, stalled, reconnecting | sending **†** | `[cancelReconnect, disarmPoll]`, ownership=local |
+| `STREAM_START{runId}` (SDK `start` metadata) | sending, attaching, reconnecting, superseding | streaming | `[cancelReconnect, disarmPoll]`, runFact←runId |
+| `FINISH_CLEAN` (onFinish clean) | streaming, … | idle | `[disarmPoll, cancelReconnect]`, runFact←null |
+| `FINISH_ABORT` (onFinish isAbort) | streaming, stopping | idle | `[disarmPoll, cancelReconnect]`, runFact←null (I4 exits stopping by this DATA) |
+| `FINISH_DISCONNECT` (observer, NOT liveFollow) | streaming(observer) | polling(disconnect-visible) | `[armPoll]` (a mount-resume drop polls) |
+| `FINISH_DISCONNECT{hasVisibleContent}` (local drop OR liveFollow) | streaming | reconnecting(1) **†** *iff runFact\|liveFollow* | `[scheduleReconnect(1)]` (+`armPoll` if visible), ownership=observer, liveFollow=true (commit 3: repeatable) |
+| `FINISH_DISCONNECT` (no runFact, not liveFollow) | streaming | idle | runFact←null (plain terminal "connection lost") |
+| `STREAM_INCOMPLETE{reason}` (observer starved/torn clean finish) | streaming(observer) | polling(reason) | `[armPoll(reason)]` |
+| `FINISH_ERROR{kind}` (onFinish isError) | any | error(kind) | `[disarmPoll, cancelReconnect]`, runFact←null |
+| `STREAM_START{runId}` (first assistant frame of a local turn) | sending | streaming | runFact←runId, `[cancelReconnect, disarmPoll]` |
+| `ATTACH_START{runId}` (mount resume) | **idle only** (F2) | attaching **†** | `[resumeStream]`, ownership=observer, runFact←runId; ignored from any non-idle phase |
+| `ATTACH_LIVE` (attach GET 2xx) | attaching | streaming | — |
+| `ATTACH_NONE` (attach GET 204/err/throw) | attaching | polling(attach-none) | `[armPoll(attach-none)]` |
+| `RECONNECT_ATTEMPT{n}` (backoff timer) | reconnecting | reconnecting(n) **†** | `[resumeStream]` |
+| `RECONNECT_ATTACHED` (reconnect GET 2xx) | reconnecting | streaming | `[cancelReconnect, disarmPoll]` — **counter reset** (commit 3) |
+| `RECONNECT_NONE` (reconnect GET 204/err), attempt<MAX | reconnecting | reconnecting(n+1) **†** | `[armPoll(attach-none), scheduleReconnect(n+1)]` |
+| `RECONNECT_NONE`, attempt=MAX | reconnecting | reconnecting(MAX, failed) | `[armPoll(reconnect-exhausted)]` |
+| `RETRY` (manual, failed banner) | reconnecting(failed) | reconnecting(1) **†** | `[resumeStream]` |
+| `RETRY` (manual, stalled banner) | stalled | polling(attach-none) **†** | `[armPoll]` |
+| `POLL_TERMINAL` (settled tail merged) | polling, reconnecting, stopping | idle | `[disarmPoll, cancelReconnect]`, runFact←null (I4) |
+| `POLL_IDLE_CAP` (inactivity cap) | polling, reconnecting | stalled | `[disarmPoll, cancelReconnect]` (commit 4a — no more silent) |
+| `POLL_IDLE_CAP` (inactivity cap) | stopping | idle | `[disarmPoll, cancelReconnect]`, runFact←null (Review #4: a Stop-armed poll with no SDK/terminal backstop gets a bounded exit — NOT `stalled`, Stop was already pressed so nothing to retry) |
+| `RUN_FACT{null}` (POST /run → null/terminal, 204) | reconnecting/attaching/polling/stopping | idle | `[cancelReconnect, disarmPoll]`, runFact←null (I3 fresh-negative gate) |
+| `RUN_FACT{runId}` | any | (same) | runFact←runId (pessimism toward an attempt) |
+| `STOP_REQUESTED` (user Stop) | streaming, reconnecting, polling | stopping **†** | `[stopRun, abortAttach, cancelReconnect, armPoll]` (poll drives the terminal — I4 exit by data) |
+| `SUPERSEDE_REQUESTED{targetRunId}` (interrupt+send) | streaming, reconnecting, polling, error | superseding **†** | `[supersede(target), cancelReconnect, disarmPoll]` |
+| `SUPERSEDE_READY{runId}` (CAS ok) | superseding | streaming | ownership=local, runFact←runId |
+| `SUPERSEDE_MISMATCH{currentRunId}` (409 SUPERSEDE_TARGET_MISMATCH) | superseding | error(supersede-mismatch) | `[postRun(verify)]`, runFact←currentRunId |
+| `SUPERSEDE_TIMEOUT` (409 SUPERSEDE_TIMEOUT) | superseding | error(supersede-timeout) | — (composer keeps text; no auto-retry) |
+| `SUPERSEDE_INVALID` (409 SUPERSEDE_INVALID) | superseding | error(supersede-invalid) | — |
+| `RUN_ALREADY_ACTIVE{activeRunId}` (409 A_RUN_ALREADY_ACTIVE, plain POST) | sending | error(run-already-active) | runFact←activeRunId (composer offers supersede; NO auto-retry) |
+| `DISPOSE` (unmount) | any | idle **†** | `[abortAttach, cancelReconnect, disarmPoll]` (I1/I5 — epoch++ kills late callbacks) |
+
+**`stopping` honors any finish (re-review MEDIUM):** BEFORE the epoch filter, a
+stream finish (`FINISH_*`/`STREAM_INCOMPLETE`) arriving in phase `stopping` exits
+`stopping -> idle` regardless of generation. A plain Stop has no successor stream,
+so the aborted stream's finish IS the expected end (I4 exit by data) — and it
+carries the PRE-stop generation (STOP_REQUESTED bumped the epoch), so the filter
+would otherwise strand the machine in `stopping` (no idle-cap covers it). The filter
+stays in force for `superseding` (that is the F1 supersede drop).
+
+**Epoch filter (I1):** the reducer then drops any event carrying an `epoch` that
+does not equal the current `ctx.epoch`. Outcome events (`STREAM_START`, `ATTACH_*`,
+`RECONNECT_*`, `SUPERSEDE_*`, **`FINISH_*`/`STREAM_INCOMPLETE`**, `RUN_FACT`) are
+stamped with the generation the corresponding STREAM started under (the runtime
+holds a per-owned-stream `turnEpoch`); trigger events (user actions, fresh
+disconnects) carry no epoch. **F1:** this is what makes a SUPERSEDED stream's late
+`onFinish` (a dead stream A closing after the CAS started stream B) get dropped, so
+A cannot drive the live new run into a false reconnect or reset its run-fact. The
+supersede path additionally ABORTS A and starts B only from A's onFinish (a
+microtask), because ai@6 `AbstractChat.makeRequest` corrupts overlapping streams
+(A's `finally` reads then nulls the shared `activeResponse`).
+
+**Removed events (scope-cut, internal review):** `RUN_SUPERSEDED` (a ghost feature —
+never dispatched; the observer-superseded case is handled by the degraded poll,
+which follows the latest rows regardless of runId), `RECONNECT_BEGIN` (reconnect is
+entered by `FINISH_DISCONNECT`), and `POLL_ACTIVITY` (the window's activity clock was
+removed when the idle-cap moved into the thread). The reducer and this table now
+share exactly the dispatched event set.
+
+### 409-code → event map (the real #487 contract consumed here)
+
+| Server response | Event dispatched | error kind → banner |
+|---|---|---|
+| 409 `A_RUN_ALREADY_ACTIVE` (+ body.activeRunId) | `RUN_ALREADY_ACTIVE{activeRunId}` | run-already-active → "already answering / interrupt & send" |
+| 409 `SUPERSEDE_TARGET_MISMATCH` (+ body.activeRunId) | `SUPERSEDE_MISMATCH{currentRunId}` | supersede-mismatch → verify via /run |
+| 409 `SUPERSEDE_TIMEOUT` | `SUPERSEDE_TIMEOUT` | supersede-timeout → "couldn't interrupt in time, resend" |
+| 409 `SUPERSEDE_INVALID` | `SUPERSEDE_INVALID` | supersede-invalid → "couldn't interrupt this run" |
+| 503 `A_RUN_BEGIN_FAILED` | `FINISH_ERROR{begin-failed}` | begin-failed → "could not start, temporary" |
+
+---
+
+## 2. Ref-map — every `chat-thread.tsx` ref → its new home  (MIGRATION RESOLVED)
+
+The migration is COMPLETE: the 13 run-lifecycle FLAGS below are GONE from
+`chat-thread.tsx` (collapsed into FSM phase/ctx/effects, or deleted). What remains
+are identity/data mirrors, effect-owned controllers/timers, and ONE React-liveness
+bit — none of which is a run-lifecycle flag, so the post-merge "no new flags" rule
+holds. **Pending column: empty.**
+
+| # | Old ref | Resolved to | Where now |
+|---|---|---|---|
+| 1 | `reconcileTailRef` | **FSM phase** | reconcile-merge gated on `phase ∈ {polling, reconnecting, stopping}` |
+| 2 | `noStreamHandledRef` | **FSM epoch (I1)** | the attach outcome's epoch guard drops the stale/second outcome |
+| 3 | `onNoActiveStreamRef` | **FSM event** | transport → `handleAttachOutcome` dispatches `ATTACH_NONE`/`RECONNECT_NONE` |
+| 4 | `onReconnectAttachedRef` | **FSM event** | transport dispatches `ATTACH_LIVE` / `RECONNECT_ATTACHED` |
+| 5 | `resumedTurnRef` + `resumedTurn` state | **FSM ctx `ownership`** | `ownership==='observer'` ⇒ never flush; hides "Send now" |
+| 6 | `reconnectStateRef` + `reconnectState` state | **FSM phase** | `reconnecting(attempt,failed)` renders the banner |
+| 7 | `reconnectTimerRef` | **effect-owned timer** | owned by `scheduleReconnect`/`cancelReconnect` effects (not a flag) |
+| 8 | `flushOnAbortRef` | **DELETED** | the stop→flush dance is replaced by the CAS supersede (commit 5) |
+| 9 | `interruptNextSendRef` | **DELETED** | the server injects the interrupt note from the supersede itself |
+| 10 | `supersedeRetryRef` | **DELETED** (commit 5) | the client 409 retry ladder is gone; CAS supersede replaces it |
+| 11 | `stopPendingRef` | **FSM phase `stopping`** | the deferred stop fires from the chat-id adoption effect while `stopping` |
+| 12 | `mountedRef` | **retained (React liveness)** | orthogonal to run-lifecycle; gates imperative onFinish side-effects post-unmount. Epoch (I1) handles stale COMMAND-outcomes; DISPOSE bumps it |
+| 13 | `attemptResumeRef` | **FSM `ATTACH_START` + run-fact** | mount arms attach ONLY on a confirmed active run (commit 4b: streaming-tail status, or POST /run for a user tail) |
+| 14–15 | `anchorRef {id, stepsPersisted}` | **data** (attachStrategy) | #491 tail-only: replaced `stripRef`/`strippedRowRef`. The PERSISTED assistant row that pins the run (server invariant 6) + its step frontier N; feeds `?anchor=<id>&n=<stepsPersisted>`. No strip — the seed keeps every row; entering reconnecting re-seeds from persist |
+| 16 | `attachAbortRef` | **effect-owned controller** | aborted by the `abortAttach` effect in cleanup (I5) |
+| 17–25 | `chatIdRef`, `openPageRef`, `getEditorSelectionRef`, `roleIdRef`, `stableIdRef`, `queuedRef`, `sendMessageRef`, `statusRef`, `lastForwardedChatIdRef` | **data** (identity/send mirrors) | unchanged — not lifecycle flags |
+| NEW | `pendingSupersedeRef` | **data** (send-plumbing) | the runId injected into the next `POST /stream {supersede}`; the single replacement for the 3 DELETED one-shots (#8/#9/#10) — net −2 refs |
+| NEW | `idleCapTimerRef` | **effect-owned timer** | the stalled inactivity cap → `POLL_IDLE_CAP` (commit 4a); not a flag |
+
+Net: the 13 lifecycle flags (#1–#13) are eliminated: **8** → FSM phase/ctx/epoch/event
+(#1–#6, #11, #13), **3** deleted (#8/#9/#10), **`reconnectTimerRef` (#7)** becomes an
+effect-owned controller, and **`mountedRef` (#12)** is retained as React liveness
+(8 + 3 + 1 + 1 = 13). (`attachAbortRef` (#16) is outside the #1–#13 set — it was
+already an effect-owned controller.) Two effect-owned timers + one send-plumbing data
+ref are added — none is a boolean lifecycle latch.
+
+---
+
+## 3. Run-fact protocol (`runFact: {runId} | null`) — I3
+
+"A run is active" is first-class from the SERVER, not inferred from an assistant
+message. Sources, in the order they update `ctx.runFact`:
+
+1. **Init (mount):** `POST /ai-chat/run { chatId }` → `{ run, message }`. A `run`
+   with a non-terminal `status` seeds `runFact = { runId: run.id }`; a null/terminal
+   run seeds `null`. This is what arms the resume attempt (`ATTACH_START`) — the
+   attempt is armed ONLY on a positive fact (commit 4b: a user-tail with no active
+   run no longer arms a pointless poll on every open).
+2. **Live update:** the `start` stream metadata carries `runId` → `STREAM_START{runId}`.
+3. **Attach outcomes:** `ATTACH_LIVE` (2xx) confirms active; a 204 on a non-stripped
+   path is an authoritative NEGATIVE fact → the runtime dispatches `RUN_FACT{null}`,
+   which cancels recovery (I3 fresh-negative gate).
+4. **Poll (#491, implemented):** the degraded poll now hits the delta endpoint
+   (`POST /ai-chat/messages/delta`), which ALREADY carries the run fact
+   (`run: {id, status} | null`) alongside the changed rows. The client does NOT yet
+   consume that run field — it still drives to a terminal ROW (merged by id),
+   dispatched as `POLL_TERMINAL` — so the run field rides the wire for a future
+   client that settles straight off it.
+
+Pessimism rule: a stale-but-positive fact PERMITS entering recovery (attach); the
+204 then cuts it. A fresh negative fact gates recovery OUT immediately.
+
+---
+
+## 4. Invariants
+
+- **I1 — Epoch (generation counter).** Every command-emitting transition bumps
+  `ctx.epoch`; every async outcome event carries its issuing epoch; the reducer
+  drops stale-epoch outcomes. Replaces the one-shot-ref zoo (`noStreamHandledRef`,
+  the flush/interrupt/supersede one-shots, the `mountedRef` late-callback gate).
+- **I2 — Ownership is context, not state.** `local | observer` is orthogonal to the
+  transport phase. The queue flushes ONLY under local ownership; an observer
+  following a detached run never flushes (was `resumedTurnRef`).
+- **I3 — Run-fact is first-class from the server.** Reconnect is entered by the
+  run-fact, not by an assistant message (commit 2). A fresh negative fact cancels
+  recovery.
+- **I4 — Exit `stopping` by DATA.** A terminal row / negative run-fact / terminal
+  finish exits `stopping`, never the stopRun HTTP response (which returns after the
+  abort but before finalization — keying off it would unlock the composer on a 409).
+- **I5 — Dispose protocol.** Command controllers (attach GET, POST /stream, POST
+  /run) are effect-owned and aborted in cleanup (`abortAttach` on `DISPOSE`), not
+  render-phase refs. A client abort of an already-sent POST does not cancel the
+  server action, so disarming on unmount is safe.
+- **attachStrategy** is behind the `resumeStream` effect; #491 swapped it to
+  tail-only (`?anchor=&n=`, `anchorRef` data) WITHOUT touching the FSM. Entering
+  reconnecting always re-seeds from persist; on a getRun failure the live partial
+  is dropped + replay-from-start so it is never the tail-apply base (no #137/#161
+  duplication).
+- **Queue** stays a data structure; flush/interrupt decisions are transitions.

apps/client/src/features/ai-chat/state/run-fsm.test.ts

@@ -0,0 +1,482 @@
+import { describe, it, expect } from "vitest";
+import {
+  reduce,
+  initialMachine,
+  reconnectDelayMs,
+  RECONNECT_MAX_ATTEMPTS,
+  type Machine,
+  type Effect,
+  type Event,
+} from "./run-fsm";
+
+// Drive a sequence of events through the reducer, returning the final machine.
+function run(m: Machine, ...events: Event[]): Machine {
+  return events.reduce(reduce, m);
+}
+function withRunFact(runId = "run-1"): Machine {
+  return {
+    ...initialMachine(),
+    ctx: { epoch: 0, ownership: "local", runFact: { runId }, liveFollow: false },
+  };
+}
+function effectTypes(m: Machine): string[] {
+  return m.effects.map((e) => e.type);
+}
+function hasEffect(m: Machine, type: Effect["type"]): boolean {
+  return m.effects.some((e) => e.type === type);
+}
+
+describe("run-fsm — epoch invariant (I1)", () => {
+  it("drops an outcome carrying a stale epoch", () => {
+    // A command bumps the epoch; an outcome stamped with the OLD epoch is dropped.
+    const m0 = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" }); // epoch 0->1, attaching
+    expect(m0.ctx.epoch).toBe(1);
+    expect(m0.phase.name).toBe("attaching");
+    // A late ATTACH_LIVE from a SUPERSEDED attempt (epoch 0) must NOT drive us.
+    const stale = reduce(m0, { type: "ATTACH_LIVE", epoch: 0 });
+    expect(stale.phase.name).toBe("attaching");
+    expect(stale.effects).toEqual([]);
+  });
+
+  it("applies an outcome carrying the current epoch", () => {
+    const m0 = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    const live = reduce(m0, { type: "ATTACH_LIVE", epoch: m0.ctx.epoch });
+    expect(live.phase.name).toBe("streaming");
+  });
+
+  it("an outcome with no epoch is never dropped (trigger events)", () => {
+    const m0 = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    const disposed = reduce(m0, { type: "DISPOSE" });
+    expect(disposed.phase.name).toBe("idle");
+    expect(hasEffect(disposed, "abortAttach")).toBe(true);
+  });
+
+  it("every command-transition increments the epoch exactly once", () => {
+    let m = initialMachine();
+    const before = m.ctx.epoch;
+    m = reduce(m, { type: "SEND_LOCAL" });
+    expect(m.ctx.epoch).toBe(before + 1);
+    m = reduce(m, { type: "STOP_REQUESTED" });
+    expect(m.ctx.epoch).toBe(before + 2);
+  });
+});
+
+describe("run-fsm — local turn", () => {
+  it("SEND_LOCAL → sending, local ownership, cancels recovery", () => {
+    const m = reduce(withRunFact(), { type: "SEND_LOCAL" });
+    expect(m.phase.name).toBe("sending");
+    expect(m.ctx.ownership).toBe("local");
+    expect(effectTypes(m)).toEqual(
+      expect.arrayContaining(["cancelReconnect", "disarmPoll"]),
+    );
+  });
+
+  it("STREAM_START adopts the runId into the run-fact and goes streaming", () => {
+    const m = run(initialMachine(), { type: "SEND_LOCAL" });
+    const s = reduce(m, { type: "STREAM_START", runId: "run-9", epoch: m.ctx.epoch });
+    expect(s.phase.name).toBe("streaming");
+    expect(s.ctx.runFact).toEqual({ runId: "run-9" });
+  });
+
+  it("FINISH_CLEAN → idle, run-fact cleared, poll/reconnect disarmed", () => {
+    const streaming = run(initialMachine(), { type: "SEND_LOCAL" }, { type: "STREAM_START", runId: "r" });
+    const done = reduce(streaming, { type: "FINISH_CLEAN" });
+    expect(done.phase.name).toBe("idle");
+    expect(done.ctx.runFact).toBeNull();
+  });
+});
+
+// #488 commit 2 — SSE break BEFORE the first assistant frame must still recover.
+describe("run-fsm — commit 2: reconnect by run-fact, not by assistant message", () => {
+  it("FINISH_DISCONNECT with an active run-fact → reconnecting (even with no visible content)", () => {
+    // Setup-phase break: no assistant frame yet, but a run-fact exists.
+    const streaming = withRunFact("run-2");
+    const m = reduce(streaming, {
+      type: "FINISH_DISCONNECT",
+      hasVisibleContent: false,
+      epoch: streaming.ctx.epoch,
+    });
+    expect(m.phase.name).toBe("reconnecting");
+    if (m.phase.name === "reconnecting") expect(m.phase.attempt).toBe(1);
+    expect(m.ctx.ownership).toBe("observer");
+    expect(hasEffect(m, "scheduleReconnect")).toBe(true);
+    // No visible content -> no poll arm yet (the reconnect ladder rebuilds it).
+    expect(hasEffect(m, "armPoll")).toBe(false);
+  });
+
+  it("FINISH_DISCONNECT WITH visible content also arms the poll", () => {
+    const m = reduce(withRunFact("run-2"), {
+      type: "FINISH_DISCONNECT",
+      hasVisibleContent: true,
+      epoch: 0,
+    });
+    expect(m.phase.name).toBe("reconnecting");
+    expect(hasEffect(m, "armPoll")).toBe(true);
+  });
+
+  it("FINISH_DISCONNECT with NO run-fact → idle (plain connection-lost)", () => {
+    const m = reduce(initialMachine(), {
+      type: "FINISH_DISCONNECT",
+      hasVisibleContent: true,
+      epoch: 0,
+    });
+    expect(m.phase.name).toBe("idle");
+  });
+});
+
+// #488 commit 3 — a SECOND break after a successful re-attach starts a NEW ladder.
+describe("run-fsm — commit 3: repeated reconnect cycles", () => {
+  it("two breaks in a row produce two reconnect cycles (counter resets on attach)", () => {
+    let m = withRunFact("run-3");
+    // First break -> reconnecting(1).
+    m = reduce(m, { type: "FINISH_DISCONNECT", hasVisibleContent: false, epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("reconnecting");
+    // Attempt fires, re-attaches live.
+    m = reduce(m, { type: "RECONNECT_ATTEMPT", attempt: 1, epoch: m.ctx.epoch });
+    m = reduce(m, { type: "RECONNECT_ATTACHED", epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("streaming");
+    // SECOND break: the counter was reset, so a fresh ladder starts at attempt 1
+    // (the old one-shot !wasResumed gate would have sent this to silent poll).
+    m = reduce(m, { type: "FINISH_DISCONNECT", hasVisibleContent: false, epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("reconnecting");
+    if (m.phase.name === "reconnecting") expect(m.phase.attempt).toBe(1);
+    expect(hasEffect(m, "scheduleReconnect")).toBe(true);
+  });
+
+  it("a MOUNT-attach observer drop falls to POLL, not the reconnect ladder", () => {
+    // Distinguishes commit 3 from a one-shot resume: an observer that never
+    // live-followed (liveFollow false) polls on a drop.
+    let m = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    m = reduce(m, { type: "ATTACH_LIVE", epoch: m.ctx.epoch });
+    expect(m.ctx.ownership).toBe("observer");
+    expect(m.ctx.liveFollow).toBe(false);
+    m = reduce(m, { type: "FINISH_DISCONNECT", hasVisibleContent: true, epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("polling");
+    expect(hasEffect(m, "armPoll")).toBe(true);
+  });
+
+  it("STREAM_INCOMPLETE (observer starved/torn finish) → polling", () => {
+    let m = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    m = reduce(m, { type: "ATTACH_LIVE", epoch: m.ctx.epoch });
+    m = reduce(m, { type: "STREAM_INCOMPLETE", reason: "starved", epoch: m.ctx.epoch });
+    expect(m.phase).toEqual({ name: "polling", reason: "starved" });
+    expect(hasEffect(m, "armPoll")).toBe(true);
+  });
+
+  it("liveFollow is set on the first local drop and kept across a re-attach", () => {
+    let m = withRunFact("run-3");
+    m = reduce(m, { type: "FINISH_DISCONNECT", hasVisibleContent: false, epoch: m.ctx.epoch });
+    expect(m.ctx.liveFollow).toBe(true);
+    m = reduce(m, { type: "RECONNECT_ATTEMPT", attempt: 1, epoch: m.ctx.epoch });
+    m = reduce(m, { type: "RECONNECT_ATTACHED", epoch: m.ctx.epoch });
+    expect(m.ctx.liveFollow).toBe(true); // kept — so a second drop reconnects
+    // A clean finish clears it.
+    m = reduce(m, { type: "FINISH_CLEAN", epoch: m.ctx.epoch });
+    expect(m.ctx.liveFollow).toBe(false);
+  });
+
+  it("RECONNECT_NONE backs off through the ladder, then fails at the cap", () => {
+    let m = withRunFact("run-3");
+    m = reduce(m, { type: "FINISH_DISCONNECT", hasVisibleContent: false, epoch: m.ctx.epoch });
+    for (let n = 1; n < RECONNECT_MAX_ATTEMPTS; n++) {
+      m = reduce(m, { type: "RECONNECT_ATTEMPT", attempt: n, epoch: m.ctx.epoch });
+      m = reduce(m, { type: "RECONNECT_NONE", epoch: m.ctx.epoch });
+      expect(m.phase.name).toBe("reconnecting");
+      if (m.phase.name === "reconnecting") {
+        expect(m.phase.attempt).toBe(n + 1);
+        expect(m.phase.failed).toBe(false);
+      }
+      // The belt-and-suspenders poll is armed each failed attempt.
+      expect(hasEffect(m, "armPoll")).toBe(true);
+    }
+    // Final attempt fails -> failed banner (Retry), poll armed.
+    m = reduce(m, { type: "RECONNECT_ATTEMPT", attempt: RECONNECT_MAX_ATTEMPTS, epoch: m.ctx.epoch });
+    m = reduce(m, { type: "RECONNECT_NONE", epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("reconnecting");
+    if (m.phase.name === "reconnecting") expect(m.phase.failed).toBe(true);
+    // RETRY restarts at attempt 1.
+    m = reduce(m, { type: "RETRY" });
+    expect(m.phase.name).toBe("reconnecting");
+    if (m.phase.name === "reconnecting") {
+      expect(m.phase.attempt).toBe(1);
+      expect(m.phase.failed).toBe(false);
+    }
+    expect(hasEffect(m, "resumeStream")).toBe(true);
+  });
+
+  it("reconnectDelayMs is the exponential backoff 1s,2s,4s,8s,16s", () => {
+    expect([1, 2, 3, 4, 5].map(reconnectDelayMs)).toEqual([1000, 2000, 4000, 8000, 16000]);
+  });
+});
+
+// #488 commit 4 — polling stalled-state + user-tail gating.
+describe("run-fsm — commit 4: stalled + run-fact gating", () => {
+  it("POLL_IDLE_CAP: polling → stalled with a banner (poll disarmed), not silent", () => {
+    let m = reduce(withRunFact(), { type: "ATTACH_START", runId: "r" });
+    m = reduce(m, { type: "ATTACH_NONE", epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("polling");
+    m = reduce(m, { type: "POLL_IDLE_CAP" });
+    expect(m.phase.name).toBe("stalled");
+    expect(hasEffect(m, "disarmPoll")).toBe(true);
+  });
+
+  it("RETRY from stalled re-arms the poll", () => {
+    let m = reduce(withRunFact(), { type: "ATTACH_START", runId: "r" });
+    m = reduce(m, { type: "ATTACH_NONE", epoch: m.ctx.epoch });
+    m = reduce(m, { type: "POLL_IDLE_CAP" });
+    m = reduce(m, { type: "RETRY" });
+    expect(m.phase.name).toBe("polling");
+    expect(hasEffect(m, "armPoll")).toBe(true);
+  });
+
+  it("a fresh NEGATIVE run-fact while attaching cancels recovery (user-tail, no active run)", () => {
+    // The mount POST /run returns no active run: attaching → idle, no poll armed.
+    let m = reduce(withRunFact(), { type: "ATTACH_START", runId: "r" });
+    m = reduce(m, { type: "RUN_FACT", runFact: null, epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("idle");
+    expect(m.ctx.runFact).toBeNull();
+    expect(hasEffect(m, "disarmPoll")).toBe(true);
+  });
+
+  it("a negative run-fact while polling stops the poll", () => {
+    let m = reduce(withRunFact(), { type: "ATTACH_START", runId: "r" });
+    m = reduce(m, { type: "ATTACH_NONE", epoch: m.ctx.epoch });
+    m = reduce(m, { type: "RUN_FACT", runFact: null, epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("idle");
+  });
+
+  it("POLL_TERMINAL settles polling → idle (I4 data-driven exit)", () => {
+    let m = reduce(withRunFact(), { type: "ATTACH_START", runId: "r" });
+    m = reduce(m, { type: "ATTACH_NONE", epoch: m.ctx.epoch });
+    m = reduce(m, { type: "POLL_TERMINAL" });
+    expect(m.phase.name).toBe("idle");
+    expect(m.ctx.runFact).toBeNull();
+  });
+});
+
+// #488 commit 5 — error classification + supersede CAS transitions.
+describe("run-fsm — commit 5: supersede CAS + error classification", () => {
+  it("SUPERSEDE_REQUESTED → superseding, fires the CAS effect, bumps epoch", () => {
+    const streaming = withRunFact("run-old");
+    const m = reduce(streaming, { type: "SUPERSEDE_REQUESTED", targetRunId: "run-old" });
+    expect(m.phase.name).toBe("superseding");
+    expect(m.ctx.epoch).toBe(streaming.ctx.epoch + 1);
+    const sup = m.effects.find((e) => e.type === "supersede");
+    expect(sup).toEqual({ type: "supersede", targetRunId: "run-old" });
+  });
+
+  it("SUPERSEDE_READY → streaming as the new local owner", () => {
+    let m = reduce(withRunFact("run-old"), { type: "SUPERSEDE_REQUESTED", targetRunId: "run-old" });
+    m = reduce(m, { type: "SUPERSEDE_READY", runId: "run-new", epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("streaming");
+    expect(m.ctx.ownership).toBe("local");
+    expect(m.ctx.runFact).toEqual({ runId: "run-new" });
+  });
+
+  it("SUPERSEDE_MISMATCH → error(supersede-mismatch) + verify via /run (no blind banner)", () => {
+    let m = reduce(withRunFact("run-old"), { type: "SUPERSEDE_REQUESTED", targetRunId: "run-old" });
+    m = reduce(m, { type: "SUPERSEDE_MISMATCH", currentRunId: "run-x", epoch: m.ctx.epoch });
+    expect(m.phase).toEqual({ name: "error", kind: "supersede-mismatch" });
+    expect(hasEffect(m, "postRun")).toBe(true);
+    expect(m.ctx.runFact).toEqual({ runId: "run-x" });
+  });
+
+  it("SUPERSEDE_TIMEOUT → error(supersede-timeout), no auto-retry effect", () => {
+    let m = reduce(withRunFact("run-old"), { type: "SUPERSEDE_REQUESTED", targetRunId: "run-old" });
+    m = reduce(m, { type: "SUPERSEDE_TIMEOUT", epoch: m.ctx.epoch });
+    expect(m.phase).toEqual({ name: "error", kind: "supersede-timeout" });
+    expect(m.effects).toEqual([]);
+  });
+
+  it("SUPERSEDE_INVALID → error(supersede-invalid)", () => {
+    let m = reduce(withRunFact("run-old"), { type: "SUPERSEDE_REQUESTED", targetRunId: "run-old" });
+    m = reduce(m, { type: "SUPERSEDE_INVALID", epoch: m.ctx.epoch });
+    expect(m.phase).toEqual({ name: "error", kind: "supersede-invalid" });
+  });
+
+  it("a stale SUPERSEDE outcome from a superseded epoch is dropped", () => {
+    let m = reduce(withRunFact("run-old"), { type: "SUPERSEDE_REQUESTED", targetRunId: "run-old" });
+    const supersedingEpoch = m.ctx.epoch;
+    // The user retriggers, bumping the epoch again.
+    m = reduce(m, { type: "SUPERSEDE_REQUESTED", targetRunId: "run-old" });
+    // The first CAS's late TIMEOUT (old epoch) must NOT knock us out of superseding.
+    const late = reduce(m, { type: "SUPERSEDE_TIMEOUT", epoch: supersedingEpoch });
+    expect(late.phase.name).toBe("superseding");
+  });
+
+  it("RUN_ALREADY_ACTIVE (plain POST gate) → error(run-already-active), no retry effect", () => {
+    const m = reduce(run(initialMachine(), { type: "SEND_LOCAL" }), { type: "RUN_ALREADY_ACTIVE" });
+    expect(m.phase).toEqual({ name: "error", kind: "run-already-active" });
+    expect(m.effects).toEqual([]);
+  });
+
+  it("#497/S4: RUN_ALREADY_ACTIVE{activeRunId} ADOPTS the server's active run as the run-fact", () => {
+    // The server sends `activeRunId` so a later supersede can TARGET that run
+    // instead of a blind promote+abort. Absorb it into runFact.
+    const m = reduce(run(initialMachine(), { type: "SEND_LOCAL" }), {
+      type: "RUN_ALREADY_ACTIVE",
+      activeRunId: "run-foreign",
+    });
+    expect(m.phase).toEqual({ name: "error", kind: "run-already-active" });
+    expect(m.ctx.runFact).toEqual({ runId: "run-foreign" });
+    expect(m.effects).toEqual([]);
+  });
+
+  it("#497/S4: RUN_ALREADY_ACTIVE without an activeRunId keeps the prior run-fact", () => {
+    const seeded = reduce(run(initialMachine(), { type: "SEND_LOCAL" }), {
+      type: "RUN_FACT",
+      runFact: { runId: "run-prior" },
+    });
+    const m = reduce(seeded, { type: "RUN_ALREADY_ACTIVE" });
+    expect(m.ctx.runFact).toEqual({ runId: "run-prior" });
+  });
+});
+
+// #488 F2 — a late mount `getRun → ATTACH_START` must not hijack a local turn.
+describe("run-fsm — F2: ATTACH_START only from idle", () => {
+  it("ATTACH_START from a local `sending` turn is ignored (no observer hijack)", () => {
+    const sending = reduce(initialMachine(), { type: "SEND_LOCAL" }); // idle -> sending, local
+    const m = reduce(sending, { type: "ATTACH_START", runId: "r" });
+    expect(m.phase.name).toBe("sending");
+    expect(m.ctx.ownership).toBe("local"); // NOT flipped to observer
+    expect(m.effects).toEqual([]); // no resumeStream
+  });
+
+  it("ATTACH_START from idle attaches as normal", () => {
+    const m = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    expect(m.phase.name).toBe("attaching");
+    expect(m.ctx.ownership).toBe("observer");
+    expect(hasEffect(m, "resumeStream")).toBe(true);
+  });
+});
+
+describe("run-fsm — stop (I4: exit by data)", () => {
+  it("STOP_REQUESTED → stopping, fires stopRun + abortAttach, no data-independent exit", () => {
+    const m = reduce(withRunFact(), { type: "STOP_REQUESTED" });
+    expect(m.phase.name).toBe("stopping");
+    expect(effectTypes(m)).toEqual(expect.arrayContaining(["stopRun", "abortAttach"]));
+  });
+
+  it("stopping exits on the aborted stream's finish carrying the PRE-STOP epoch", () => {
+    // MEDIUM (#488 re-review): STOP_REQUESTED is a command that BUMPS the epoch, but
+    // the runtime stamps the aborted stream's onFinish with the stream's START (pre-
+    // stop) generation — exactly what the component sends. `stopping` must HONOR
+    // that finish regardless of generation (no idle-cap covers `stopping`).
+    // MUTATION-VERIFY: remove the honor-in-`stopping` branch and this hangs in
+    // `stopping` (the epoch filter drops the pre-stop finish) -> red.
+    const preStopEpoch = withRunFact().ctx.epoch; // E1 (the stream's start epoch)
+    let m = reduce(withRunFact(), { type: "STOP_REQUESTED" }); // E1 -> E2, stopping
+    expect(m.ctx.epoch).toBe(preStopEpoch + 1);
+    m = reduce(m, { type: "FINISH_ABORT", epoch: preStopEpoch }); // NOT the current epoch
+    expect(m.phase.name).toBe("idle");
+    expect(m.ctx.runFact).toBeNull();
+  });
+
+  it("stopping exits on a clean finish carrying the pre-stop epoch too", () => {
+    const preStopEpoch = withRunFact().ctx.epoch;
+    let m = reduce(withRunFact(), { type: "STOP_REQUESTED" });
+    m = reduce(m, { type: "FINISH_CLEAN", epoch: preStopEpoch });
+    expect(m.phase.name).toBe("idle");
+  });
+
+  it("stopping exits on a negative run-fact (data)", () => {
+    let m = reduce(withRunFact(), { type: "STOP_REQUESTED" });
+    m = reduce(m, { type: "RUN_FACT", runFact: null, epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("idle");
+  });
+
+  // Review #4: `stopping` arms the poll but had no inactivity backstop.
+  it("review-4: POLL_IDLE_CAP in `stopping` exits to idle (bounded), NOT stalled", () => {
+    let m = reduce(withRunFact(), { type: "STOP_REQUESTED" });
+    expect(m.phase.name).toBe("stopping");
+    expect(hasEffect(m, "armPoll")).toBe(true);
+    // MUTATION-VERIFY: drop the `stopping` branch in POLL_IDLE_CAP and this hangs
+    // in `stopping` (poll forever) -> red.
+    m = reduce(m, { type: "POLL_IDLE_CAP" });
+    expect(m.phase.name).toBe("idle");
+    expect(hasEffect(m, "disarmPoll")).toBe(true);
+    expect(m.ctx.ownership).toBe("local");
+  });
+});
+
+// Review #1: positive attach outcomes must be guarded by the SOURCE phase — the
+// epoch filter alone is insufficient because POLL_TERMINAL uses to() (no epoch
+// bump) and does not abort the in-flight GET.
+describe("run-fsm — review-1: attach outcomes guarded by source phase", () => {
+  it("a late RECONNECT_ATTACHED after POLL_TERMINAL stays idle (no phantom streaming)", () => {
+    let m = withRunFact("run-1");
+    m = reduce(m, { type: "FINISH_DISCONNECT", hasVisibleContent: true, epoch: m.ctx.epoch });
+    m = reduce(m, { type: "RECONNECT_ATTEMPT", attempt: 1, epoch: m.ctx.epoch }); // attach GET
+    const epoch = m.ctx.epoch;
+    // The armed degraded poll reaches the terminal row FIRST (epoch unchanged).
+    m = reduce(m, { type: "POLL_TERMINAL" });
+    expect(m.phase.name).toBe("idle");
+    expect(m.ctx.epoch).toBe(epoch); // POLL_TERMINAL did NOT bump the epoch
+    // The slow GET returns live 2xx under the SAME epoch — must NOT resurrect.
+    m = reduce(m, { type: "RECONNECT_ATTACHED", epoch });
+    expect(m.phase.name).toBe("idle");
+  });
+
+  it("a late ATTACH_LIVE / ATTACH_NONE after leaving `attaching` is ignored", () => {
+    let m = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    const epoch = m.ctx.epoch;
+    m = reduce(m, { type: "ATTACH_NONE", epoch }); // attaching -> polling
+    m = reduce(m, { type: "POLL_TERMINAL" }); // -> idle (epoch unchanged)
+    expect(m.phase.name).toBe("idle");
+    m = reduce(m, { type: "ATTACH_LIVE", epoch }); // late 2xx, same epoch
+    expect(m.phase.name).toBe("idle");
+    // And a late ATTACH_NONE (not `attaching`) is a no-op too.
+    m = reduce(m, { type: "ATTACH_NONE", epoch });
+    expect(m.phase.name).toBe("idle");
+  });
+});
+
+// Review #2: every terminal transition resets ownership to local.
+describe("run-fsm — review-2: terminal transitions reset ownership to local", () => {
+  const observer = (): Machine => {
+    let m = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    m = reduce(m, { type: "ATTACH_LIVE", epoch: m.ctx.epoch });
+    expect(m.ctx.ownership).toBe("observer");
+    return m;
+  };
+  it("FINISH_CLEAN resets ownership", () => {
+    const m = reduce(observer(), { type: "FINISH_CLEAN", epoch: observer().ctx.epoch });
+    expect(m.ctx.ownership).toBe("local");
+  });
+  it("FINISH_ERROR / POLL_TERMINAL / RUN_FACT(null) reset ownership", () => {
+    let o = observer();
+    expect(reduce(o, { type: "FINISH_ERROR", kind: "stream", epoch: o.ctx.epoch }).ctx.ownership).toBe("local");
+    // POLL_TERMINAL from an observer polling phase
+    let p = reduce(observer(), { type: "STREAM_INCOMPLETE", reason: "starved", epoch: observer().ctx.epoch });
+    expect(reduce(p, { type: "POLL_TERMINAL" }).ctx.ownership).toBe("local");
+    // RUN_FACT(null) from an observer attaching phase
+    let a = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    expect(reduce(a, { type: "RUN_FACT", runFact: null, epoch: a.ctx.epoch }).ctx.ownership).toBe("local");
+  });
+});
+
+describe("run-fsm — ownership (I2) is context, orthogonal to phase", () => {
+  it("attach/reconnect set observer; send/supersede-ready set local", () => {
+    let m = reduce(initialMachine(), { type: "ATTACH_START", runId: "r" });
+    expect(m.ctx.ownership).toBe("observer");
+    m = reduce(m, { type: "ATTACH_LIVE", epoch: m.ctx.epoch });
+    expect(m.phase.name).toBe("streaming");
+    expect(m.ctx.ownership).toBe("observer"); // still observing a detached run
+    // A local send flips ownership back to local.
+    m = reduce(m, { type: "SEND_LOCAL" });
+    expect(m.ctx.ownership).toBe("local");
+  });
+});
+
+describe("run-fsm — dispose (I5)", () => {
+  it("DISPOSE from any phase aborts controllers and bumps epoch", () => {
+    let m = reduce(withRunFact(), { type: "ATTACH_START", runId: "r" });
+    const before = m.ctx.epoch;
+    m = reduce(m, { type: "DISPOSE" });
+    expect(m.phase.name).toBe("idle");
+    expect(m.ctx.epoch).toBe(before + 1);
+    expect(effectTypes(m)).toEqual(
+      expect.arrayContaining(["abortAttach", "cancelReconnect", "disarmPoll"]),
+    );
+  });
+});

apps/client/src/features/ai-chat/state/run-fsm.ts

@@ -0,0 +1,600 @@
+/**
+ * Run-lifecycle finite state machine for a single AI-chat thread (#488).
+ *
+ * ============================================================================
+ * WHY THIS EXISTS
+ * ----------------------------------------------------------------------------
+ * The resume/reconnect/poll/stop/supersede lifecycle used to be spread across
+ * ~26 `useRef` one-shot flags in `chat-thread.tsx`, each disarmed "on every
+ * path". Ownerless flag combinations produced silent UI freezes, and every fix
+ * added another ref (the #381 -> #432 -> #456 spiral). This module replaces that
+ * ref-zoo with ONE pure reducer whose transitions are enumerable and unit-
+ * testable in isolation (event x state -> next state is the observable property).
+ *
+ * The reducer is PURE: it owns no timers, no fetches, no React state. It maps
+ * `(machine, event) -> machine`, where the returned machine carries the list of
+ * COMMAND EFFECTS to run for that transition. A thin runtime in `chat-thread.tsx`
+ * dispatches events (from SDK callbacks / HTTP outcomes) and executes the
+ * effects (attach GET, POST /stream, POST /run, POST /stop, backoff timers,
+ * poll arm/disarm). The runtime lives in a THREAD, not the window, so a late SDK
+ * callback dies with the owner (kills the "event from a dead view" class, #161).
+ *
+ * ============================================================================
+ * INVARIANTS (see run-fsm.spec.md for the full spec + tables)
+ * ----------------------------------------------------------------------------
+ *  I1  EPOCH (generation counter). Commands (`resumeStream`, `postRun`, `stop`,
+ *      `supersede`, `scheduleReconnect`) are async; their outcomes arrive on the
+ *      SAME SDK/HTTP callbacks. Every command-emitting transition increments
+ *      `ctx.epoch`; every OUTCOME event carries the epoch it was issued under;
+ *      the reducer DROPS an outcome whose epoch != the current epoch. This is
+ *      what the one-shot-ref zoo used to approximate by hand.
+ *  I2  OWNERSHIP is a CONTEXT FIELD (`'local' | 'observer'`), not a state —
+ *      orthogonal to the transport phase. The queue is flushed ONLY by a local
+ *      owner (an observer following a detached run never flushes).
+ *  I3  RUN-FACT ("a run is active") is first-class from the server: `runFact`
+ *      holds the server-confirmed active run id (POST /run on mount, the `start`
+ *      metadata runId, attach outcomes). Reconnect is entered by the RUN-FACT,
+ *      not by the presence of an assistant message (#488 commit 2). A fresh
+ *      negative fact (null) cancels reconnect immediately.
+ *  I4  Exit `stopping` by DATA (a terminal row / negative run-fact), NEVER by the
+ *      stopRun HTTP response (which returns after abort, before finalization).
+ *  I5  Command controllers are effect-owned (abort in cleanup), NOT render-phase
+ *      refs — expressed here as the `abortAttach` effect on disposing transitions.
+ * ============================================================================
+ */
+
+// ---------------------------------------------------------------------------
+// Phases (the transport lifecycle). Ownership / runFact are CONTEXT, not here.
+// ---------------------------------------------------------------------------
+
+/** Why the degraded poll is the active recovery. */
+export type PollReason =
+  | "attach-none" // mount attach returned 204 / error — nothing live to attach
+  | "starved" // a resumed finish carried no visible content
+  | "disconnect-visible" // a live disconnect WITH on-screen content — poll to terminal
+  | "reconnect-exhausted"; // the live re-attach ladder gave up
+
+/** The classified error kind (drives the banner text + composer behavior). */
+export type ErrorKind =
+  | "stream" // a generic provider/network stream error (useChat error)
+  | "run-already-active" // 409 A_RUN_ALREADY_ACTIVE (a plain POST hit the gate)
+  | "supersede-mismatch" // 409 SUPERSEDE_TARGET_MISMATCH (CAS target moved)
+  | "supersede-timeout" // 409 SUPERSEDE_TIMEOUT (old run did not settle in W)
+  | "supersede-invalid" // 409 SUPERSEDE_INVALID (bad supersede target)
+  | "begin-failed"; // 503 A_RUN_BEGIN_FAILED (could not start the run)
+
+export type Phase =
+  | { name: "idle" }
+  | { name: "sending" } // local POST in flight, before the first frame
+  | { name: "streaming" } // receiving frames
+  | { name: "attaching" } // mount-time attach GET in flight
+  | { name: "reconnecting"; attempt: number; failed: boolean }
+  | { name: "polling"; reason: PollReason }
+  | { name: "stalled" } // poll hit the inactivity cap — banner + Retry
+  | { name: "stopping" }
+  | { name: "superseding" }
+  | { name: "error"; kind: ErrorKind };
+
+export type Ownership = "local" | "observer";
+
+/** The server-confirmed active run, or null when no run is active. */
+export type RunFact = { runId: string } | null;
+
+export interface Ctx {
+  /** I1: generation counter — every command-transition increments it. */
+  epoch: number;
+  /** I2: does THIS client own the turn's writes (local streamer) or observe? */
+  ownership: Ownership;
+  /** I3: the server-confirmed active run. */
+  runFact: RunFact;
+  /**
+   * Are we FOLLOWING a live run we were locally streaming (the reconnect ladder),
+   * as opposed to a one-shot mount-attach resume? Both are `ownership: 'observer'`,
+   * but they recover DIFFERENTLY on a drop: a live-follow drop RE-ENTERS the
+   * reconnect ladder (#488 commit 3 — the second break after a successful re-attach
+   * must reconnect again, not fall to silent poll), while a mount-resume drop falls
+   * to the degraded poll. This is the ctx bit that separates the two WITHOUT a new
+   * component ref (it is why commit 3 needs the FSM, not a surgical patch).
+   */
+  liveFollow: boolean;
+}
+
+export interface Machine {
+  phase: Phase;
+  ctx: Ctx;
+  /** Command effects to run for the transition that produced THIS machine.
+   *  The runtime executes them and does not read them again. */
+  effects: Effect[];
+}
+
+// ---------------------------------------------------------------------------
+// Command effects (the reducer's only side-channel — executed by the runtime).
+// ---------------------------------------------------------------------------
+
+export type Effect =
+  /** POST /run to (re)establish or verify the run-fact. `reason` is diagnostic. */
+  | { type: "postRun"; reason: "mount" | "verify" }
+  /** Trigger the SDK `resumeStream()` (attach GET via prepareReconnectToStream). */
+  | { type: "resumeStream" }
+  /** Schedule a reconnect attempt after a backoff, then dispatch RECONNECT_ATTEMPT. */
+  | { type: "scheduleReconnect"; attempt: number; delayMs: number }
+  /** Cancel any pending reconnect backoff timer. */
+  | { type: "cancelReconnect" }
+  /** Arm the degraded poll (the window's dumb timer follows the run in the DB). */
+  | { type: "armPoll"; reason: PollReason }
+  /** Disarm the degraded poll. */
+  | { type: "disarmPoll" }
+  /** POST /stop the chat's active run (authoritative detached-run stop). */
+  | { type: "stopRun" }
+  /** POST /stream { supersede: { runId } } — the CAS "interrupt and send now". */
+  | { type: "supersede"; targetRunId: string }
+  /** Abort the in-flight attach/reconnect GET controller (dispose / observer stop). */
+  | { type: "abortAttach" };
+
+// ---------------------------------------------------------------------------
+// Events. An OUTCOME event MAY carry `epoch`; if it does and it does not equal
+// the current epoch, the reducer drops it (I1). Trigger events (user actions,
+// fresh disconnects) carry no epoch and are never dropped.
+// ---------------------------------------------------------------------------
+
+export type Event =
+  // -- local turn --
+  | { type: "SEND_LOCAL" }
+  | { type: "STREAM_START"; runId?: string; epoch?: number }
+  /** An OBSERVER's attached stream ended WITHOUT reaching terminal (a starved
+   *  clean replay, or a torn resume) — fall to the degraded poll to drive the row
+   *  to its real terminal state. (A live-follow drop uses FINISH_DISCONNECT.) */
+  | { type: "STREAM_INCOMPLETE"; reason: PollReason; epoch?: number }
+  | { type: "FINISH_CLEAN"; epoch?: number }
+  | { type: "FINISH_ABORT"; epoch?: number }
+  | { type: "FINISH_DISCONNECT"; hasVisibleContent: boolean; epoch?: number }
+  | { type: "FINISH_ERROR"; kind: ErrorKind; epoch?: number }
+  // -- mount attach (resume) --
+  | { type: "ATTACH_START"; runId?: string }
+  | { type: "ATTACH_LIVE"; epoch?: number }
+  | { type: "ATTACH_NONE"; epoch?: number }
+  // -- reconnect after a live disconnect (entered by FINISH_DISCONNECT, #488 c2) --
+  | { type: "RECONNECT_ATTEMPT"; attempt: number; epoch?: number }
+  | { type: "RECONNECT_ATTACHED"; epoch?: number }
+  | { type: "RECONNECT_NONE"; epoch?: number }
+  | { type: "RETRY" }
+  // -- degraded poll --
+  | { type: "POLL_TERMINAL" }
+  | { type: "POLL_IDLE_CAP" }
+  // -- run-fact (server-confirmed active run) --
+  | { type: "RUN_FACT"; runFact: RunFact; epoch?: number }
+  // -- stop --
+  | { type: "STOP_REQUESTED" }
+  // -- supersede (CAS) --
+  | { type: "SUPERSEDE_REQUESTED"; targetRunId: string }
+  | { type: "SUPERSEDE_READY"; runId?: string; epoch?: number }
+  | { type: "SUPERSEDE_MISMATCH"; currentRunId?: string; epoch?: number }
+  | { type: "SUPERSEDE_TIMEOUT"; epoch?: number }
+  | { type: "SUPERSEDE_INVALID"; epoch?: number }
+  | { type: "RUN_ALREADY_ACTIVE"; activeRunId?: string }
+  // -- lifecycle --
+  | { type: "DISPOSE" };
+
+export const RECONNECT_MAX_ATTEMPTS = 5;
+export const RECONNECT_BASE_DELAY_MS = 1000;
+/** Backoff before attempt N (1-based): 1s, 2s, 4s, 8s, 16s. */
+export function reconnectDelayMs(attempt: number): number {
+  return RECONNECT_BASE_DELAY_MS * 2 ** (attempt - 1);
+}
+
+// ---------------------------------------------------------------------------
+// Constructors / helpers.
+// ---------------------------------------------------------------------------
+
+export function initialMachine(overrides?: Partial<Ctx>): Machine {
+  return {
+    phase: { name: "idle" },
+    ctx: { epoch: 0, ownership: "local", runFact: null, liveFollow: false, ...overrides },
+    effects: [],
+  };
+}
+
+/** Build a machine result: a phase, optional ctx patch, and effects. Empty
+ *  effects by default. Never mutates the input. */
+function to(
+  m: Machine,
+  phase: Phase,
+  opts?: { ctx?: Partial<Ctx>; effects?: Effect[] },
+): Machine {
+  return {
+    phase,
+    ctx: { ...m.ctx, ...(opts?.ctx ?? {}) },
+    effects: opts?.effects ?? [],
+  };
+}
+
+/** No transition: keep the phase, clear effects (so a re-run does not re-fire). */
+function stay(m: Machine): Machine {
+  return { phase: m.phase, ctx: m.ctx, effects: [] };
+}
+
+/** A command-transition: same as `to` but bumps the epoch (I1). Any outcome
+ *  event issued under the old epoch is dropped once this lands. */
+function command(
+  m: Machine,
+  phase: Phase,
+  effects: Effect[],
+  ctx?: Partial<Ctx>,
+): Machine {
+  return {
+    phase,
+    ctx: { ...m.ctx, ...(ctx ?? {}), epoch: m.ctx.epoch + 1 },
+    effects,
+  };
+}
+
+// ---------------------------------------------------------------------------
+// The pure reducer.
+// ---------------------------------------------------------------------------
+
+/** The terminal stream-finish events (one turn's stream ended). */
+function isFinishEvent(event: Event): boolean {
+  return (
+    event.type === "FINISH_ABORT" ||
+    event.type === "FINISH_CLEAN" ||
+    event.type === "FINISH_DISCONNECT" ||
+    event.type === "FINISH_ERROR" ||
+    event.type === "STREAM_INCOMPLETE"
+  );
+}
+
+export function reduce(m: Machine, event: Event): Machine {
+  // MEDIUM (#488 re-review): honor ANY stream finish in `stopping` regardless of
+  // generation. A plain user Stop has NO successor stream — the aborted stream's
+  // finish IS the expected end of the stop, so exit `stopping -> idle` by that DATA
+  // (I4). The epoch filter below must NOT drop it: STOP_REQUESTED bumped the epoch,
+  // but the finish carries the PRE-stop generation (the runtime stamps it with the
+  // stream's start epoch), so I1 would otherwise strand the machine in `stopping`
+  // forever (no idle-cap covers `stopping`). The epoch filter stays in force for
+  // `superseding` (a successor B owns) — that is the F1 supersede drop.
+  if (m.phase.name === "stopping" && isFinishEvent(event)) {
+    return to(m, { name: "idle" }, {
+      // Reset ownership to local on this terminal transition (review #2): otherwise
+      // an observer-stop leaves ownership 'observer' and hides "Send now" forever.
+      ctx: { runFact: null, liveFollow: false, ownership: "local" },
+      effects: [{ type: "disarmPoll" }, { type: "cancelReconnect" }],
+    });
+  }
+
+  // I1: drop a stale outcome (an event issued under a superseded epoch).
+  if ("epoch" in event && event.epoch !== undefined && event.epoch !== m.ctx.epoch) {
+    return stay(m);
+  }
+
+  switch (event.type) {
+    // ---- local turn ----------------------------------------------------
+    case "SEND_LOCAL":
+      // A local send owns the view: leave any recovery, become the local
+      // streamer, disarm poll/reconnect. epoch++ so a late recovery outcome
+      // from the previous phase is dropped.
+      return command(
+        m,
+        { name: "sending" },
+        [{ type: "cancelReconnect" }, { type: "disarmPoll" }],
+        { ownership: "local", liveFollow: false },
+      );
+
+    case "STREAM_INCOMPLETE":
+      // An OBSERVER's attached stream ended incomplete (starved / torn) — follow
+      // the run to terminal via the degraded poll.
+      return to(m, { name: "polling", reason: event.reason }, {
+        effects: [{ type: "armPoll", reason: event.reason }],
+      });
+
+    case "STREAM_START": {
+      // First frame arrived. Adopt the run-fact runId if present. sending ->
+      // streaming; a reconnect/attach that just went live also lands here.
+      const runFact = event.runId ? { runId: event.runId } : m.ctx.runFact;
+      return to(m, { name: "streaming" }, {
+        ctx: { runFact },
+        effects: [{ type: "cancelReconnect" }, { type: "disarmPoll" }],
+      });
+    }
+
+    case "FINISH_CLEAN":
+      // A clean terminal outcome. The run is done — clear the run-fact and go
+      // idle. (The queue flush is a component concern gated by ownership; the
+      // FSM only models the phase.) Review #2: reset ownership to local so a
+      // just-finished observer-attach turn re-exposes "Send now" for the queue.
+      return to(m, { name: "idle" }, {
+        ctx: { runFact: null, liveFollow: false, ownership: "local" },
+        effects: [{ type: "disarmPoll" }, { type: "cancelReconnect" }],
+      });
+
+    case "FINISH_ABORT":
+      // A user Stop / intentional abort finished. If we were stopping, the
+      // terminal data has now arrived (I4) — go idle. The run-fact is cleared.
+      return to(m, { name: "idle" }, {
+        ctx: { runFact: null, liveFollow: false, ownership: "local" },
+        effects: [{ type: "disarmPoll" }, { type: "cancelReconnect" }],
+      });
+
+    case "FINISH_DISCONNECT":
+      // A LIVE SSE drop. Recovery depends on WHO we are (I2 + liveFollow):
+      //  - a mount-attach OBSERVER (a one-shot resume, NOT live-follow) that drops
+      //    -> the degraded poll drives the row to terminal from the DB.
+      if (m.ctx.ownership === "observer" && !m.ctx.liveFollow) {
+        return to(m, { name: "polling", reason: "disconnect-visible" }, {
+          effects: [{ type: "armPoll", reason: "disconnect-visible" }],
+        });
+      }
+      //  - a LOCAL live turn (first drop) OR a live-follow re-attach (a SUBSEQUENT
+      //    drop) -> (re-)enter the reconnect ladder. #488 commit 3: allowed
+      //    REPEATEDLY — `liveFollow` is kept across a successful re-attach, so the
+      //    second break reconnects again instead of falling to silent poll.
+      // #488 commit 2: gated on the RUN-FACT (or an existing live-follow), NOT on
+      // the presence of an assistant message — a setup-phase break still recovers.
+      //  - visible content already on screen -> keep it, ALSO poll to terminal
+      //    (a full replay could clobber the fuller live tail);
+      //  - no visible content -> the reconnect ladder rebuilds it.
+      if (m.ctx.runFact || m.ctx.liveFollow) {
+        const effects: Effect[] = [
+          { type: "scheduleReconnect", attempt: 1, delayMs: reconnectDelayMs(1) },
+        ];
+        if (event.hasVisibleContent) effects.push({ type: "armPoll", reason: "disconnect-visible" });
+        return command(m, { name: "reconnecting", attempt: 1, failed: false }, effects, {
+          ownership: "observer",
+          liveFollow: true,
+        });
+      }
+      // No run to recover: a plain disconnect. Surface the terminal notice.
+      return to(m, { name: "idle" }, {
+        ctx: { runFact: null, liveFollow: false, ownership: "local" },
+      });
+
+    case "FINISH_ERROR":
+      return to(m, { name: "error", kind: event.kind }, {
+        ctx: { runFact: null, liveFollow: false, ownership: "local" },
+        effects: [{ type: "disarmPoll" }, { type: "cancelReconnect" }],
+      });
+
+    // ---- mount attach (resume) ----------------------------------------
+    case "ATTACH_START":
+      // A reopened tab attaches to a still-running run: observer ownership.
+      // #488 F2: ONLY from idle. The mount `getRun` round-trip resolves async, and
+      // a local send may have started meanwhile (phase `sending`, ownership local);
+      // a late ATTACH_START must NOT hijack that local turn into an observer-attach
+      // (queue would stop flushing, "Send now" would hide). Guarding in the reducer
+      // covers every dispatch source.
+      if (m.phase.name !== "idle") return stay(m);
+      return command(m, { name: "attaching" }, [{ type: "resumeStream" }], {
+        ownership: "observer",
+        runFact: event.runId ? { runId: event.runId } : m.ctx.runFact,
+      });
+
+    case "ATTACH_LIVE":
+      // The attach GET returned a live 2xx stream — follow it as an observer.
+      // Review #1: guard by SOURCE phase. The epoch filter alone is not enough — a
+      // POLL_TERMINAL uses to() (no epoch bump) and does not abort the in-flight
+      // GET, so a slow 2xx landing after the machine already left `attaching` (e.g.
+      // the armed poll saw the terminal row -> idle) would resurrect a settled run
+      // into a phantom `streaming`. Only enter streaming FROM `attaching`.
+      if (m.phase.name !== "attaching") return stay(m);
+      return to(m, { name: "streaming" });
+
+    case "ATTACH_NONE":
+      // 204 / non-2xx / throw: nothing live to attach. Arm the degraded poll to
+      // follow the run to terminal from the DB. This is a soft-negative run-fact
+      // (204 on a non-stripped path is authoritative-negative; the runtime may
+      // pass a RUN_FACT null separately). Keep the run-fact as-is here.
+      // Review #1: guard by source phase for consistency (a late outcome after the
+      // machine already left `attaching` must not re-arm a poll).
+      if (m.phase.name !== "attaching") return stay(m);
+      return to(m, { name: "polling", reason: "attach-none" }, {
+        effects: [{ type: "armPoll", reason: "attach-none" }],
+      });
+
+    // ---- reconnect after a live disconnect ----------------------------
+    case "RECONNECT_ATTEMPT":
+      // A scheduled backoff fired — fire the attach GET. epoch++ so the previous
+      // attempt's late outcome cannot drive this one.
+      if (m.phase.name !== "reconnecting") return stay(m);
+      return command(
+        m,
+        { name: "reconnecting", attempt: event.attempt, failed: false },
+        [{ type: "resumeStream" }],
+      );
+
+    case "RECONNECT_ATTACHED":
+      // #488 commit 3: a live re-attach succeeded. Reset to streaming — the
+      // attempt counter is dropped, so a LATER disconnect can start a fresh
+      // ladder from attempt 1 (the old one-shot `!wasResumed` gate forbade a
+      // second cycle, sending the second break to silent poll).
+      // Review #1: guard by SOURCE phase. The armed degraded poll can reach the
+      // terminal row (POLL_TERMINAL -> idle, via to(), NO epoch bump, GET not
+      // aborted) BEFORE a slow reconnect GET returns 2xx; without this guard that
+      // late RECONNECT_ATTACHED (same epoch) would resurrect a settled run into a
+      // phantom `streaming`. Only re-enter streaming FROM `reconnecting`.
+      if (m.phase.name !== "reconnecting") return stay(m);
+      return to(m, { name: "streaming" }, {
+        effects: [{ type: "cancelReconnect" }, { type: "disarmPoll" }],
+      });
+
+    case "RECONNECT_NONE": {
+      // 204 / error during a reconnect attempt. Arm the degraded poll as the
+      // belt-and-suspenders fallback, then either back off to the next attempt
+      // or, at the cap, surface the manual Retry ("failed").
+      if (m.phase.name !== "reconnecting") return stay(m);
+      const attempt = m.phase.attempt;
+      if (attempt < RECONNECT_MAX_ATTEMPTS) {
+        return command(
+          m,
+          { name: "reconnecting", attempt: attempt + 1, failed: false },
+          [
+            { type: "armPoll", reason: "attach-none" },
+            { type: "scheduleReconnect", attempt: attempt + 1, delayMs: reconnectDelayMs(attempt + 1) },
+          ],
+        );
+      }
+      return to(m, { name: "reconnecting", attempt, failed: true }, {
+        effects: [{ type: "armPoll", reason: "reconnect-exhausted" }],
+      });
+    }
+
+    case "RETRY":
+      // Manual Retry from the "failed" reconnect banner OR the stalled banner.
+      if (m.phase.name === "reconnecting" && m.phase.failed) {
+        return command(
+          m,
+          { name: "reconnecting", attempt: 1, failed: false },
+          [{ type: "resumeStream" }],
+        );
+      }
+      if (m.phase.name === "stalled") {
+        // Re-arm the poll to try to catch the run up again.
+        return command(m, { name: "polling", reason: "attach-none" }, [
+          { type: "armPoll", reason: "attach-none" },
+        ]);
+      }
+      return stay(m);
+
+    // ---- degraded poll -------------------------------------------------
+    case "POLL_TERMINAL":
+      // The run reached a terminal row via the poll (or the reconcile merge). Go
+      // idle and disarm everything (I4: this is a DATA-driven exit, incl. exit
+      // from `stopping`). Review #2: reset ownership to local.
+      return to(m, { name: "idle" }, {
+        ctx: { runFact: null, liveFollow: false, ownership: "local" },
+        effects: [{ type: "disarmPoll" }, { type: "cancelReconnect" }],
+      });
+
+    case "POLL_IDLE_CAP":
+      // Review #4: `stopping` also arms the poll (STOP_REQUESTED) but has NO other
+      // backstop — an observer-stop with no SDK stream to fire onFinish, whose
+      // server stop never drives the run terminal, would poll the DB forever. Give
+      // it a bounded exit: cap -> idle + disarm (NOT `stalled`; Stop was already
+      // pressed, so there is nothing for the user to retry).
+      if (m.phase.name === "stopping") {
+        return to(m, { name: "idle" }, {
+          ctx: { runFact: null, liveFollow: false, ownership: "local" },
+          effects: [{ type: "disarmPoll" }, { type: "cancelReconnect" }],
+        });
+      }
+      // #488 commit 4a: the poll hit the inactivity cap. Instead of going SILENT
+      // (the old "forever half-done answer"), surface a stalled banner + Retry.
+      if (m.phase.name !== "polling" && m.phase.name !== "reconnecting") return stay(m);
+      return to(m, { name: "stalled" }, {
+        effects: [{ type: "disarmPoll" }, { type: "cancelReconnect" }],
+      });
+
+    // ---- run-fact ------------------------------------------------------
+    case "RUN_FACT": {
+      const runFact = event.runFact;
+      // A fresh NEGATIVE fact (no active run) cancels recovery immediately (I3):
+      // there is nothing to reconnect to / poll for.
+      if (!runFact) {
+        if (
+          m.phase.name === "reconnecting" ||
+          m.phase.name === "attaching" ||
+          m.phase.name === "polling" ||
+          m.phase.name === "stopping"
+        ) {
+          return to(m, { name: "idle" }, {
+            // Review #2: reset ownership to local on this terminal transition.
+            ctx: { runFact: null, liveFollow: false, ownership: "local" },
+            effects: [{ type: "cancelReconnect" }, { type: "disarmPoll" }],
+          });
+        }
+        return to(m, m.phase, { ctx: { runFact: null } });
+      }
+      // A positive fact just updates the context (pessimism toward an attempt: a
+      // stale-but-positive fact permits entering recovery; a 204 will cut it).
+      return to(m, m.phase, { ctx: { runFact } });
+    }
+
+    // ---- stop ----------------------------------------------------------
+    case "STOP_REQUESTED":
+      // Authoritative stop of a detached run. Enter `stopping` and fire stopRun +
+      // abort the local/attach reader. ALSO arm the poll so the terminal row is
+      // observed — the exit is by DATA (I4: a terminal row / negative run-fact),
+      // never by the stopRun HTTP response (which returns after abort, before
+      // finalization). For a local turn the aborted stream's onFinish (ANY finish)
+      // is HONORED in `stopping` at the top of reduce() — regardless of generation
+      // — and exits to idle; the armed poll is the fallback for an observer stop
+      // with no local onFinish.
+      return command(
+        m,
+        { name: "stopping" },
+        [
+          { type: "stopRun" },
+          { type: "abortAttach" },
+          { type: "cancelReconnect" },
+          { type: "armPoll", reason: "attach-none" },
+        ],
+      );
+
+    // ---- supersede (CAS) ----------------------------------------------
+    case "SUPERSEDE_REQUESTED":
+      // "Interrupt and send now": CAS POST /stream { supersede }. epoch++ so a
+      // late outcome of the interrupted run is dropped.
+      return command(
+        m,
+        { name: "superseding" },
+        [{ type: "supersede", targetRunId: event.targetRunId }, { type: "cancelReconnect" }, { type: "disarmPoll" }],
+      );
+
+    case "SUPERSEDE_READY": {
+      // CAS succeeded (old run stopped/settled, slot taken, new run begun). We
+      // are now the local streamer of the NEW run. Adopt its runId if provided.
+      const runFact = event.runId ? { runId: event.runId } : m.ctx.runFact;
+      return to(m, { name: "streaming" }, {
+        ctx: { ownership: "local", runFact, liveFollow: false },
+      });
+    }
+
+    case "SUPERSEDE_MISMATCH":
+      // The active run moved between the click and the CAS. Per the spec: verify
+      // via /run rather than blindly banner — the mismatch may be our own already-
+      // superseded run. Surface a classified error AND fire a run-fact verify.
+      return to(m, { name: "error", kind: "supersede-mismatch" }, {
+        ctx: { runFact: event.currentRunId ? { runId: event.currentRunId } : m.ctx.runFact },
+        effects: [{ type: "postRun", reason: "verify" }],
+      });
+
+    case "SUPERSEDE_TIMEOUT":
+      // The old run did not settle within W. Nothing persisted; the composer keeps
+      // its text. Classified error, NO auto-retry (the old client retry ladder is
+      // removed in #488 commit 5).
+      return to(m, { name: "error", kind: "supersede-timeout" });
+
+    case "SUPERSEDE_INVALID":
+      return to(m, { name: "error", kind: "supersede-invalid" });
+
+    case "RUN_ALREADY_ACTIVE":
+      // A plain POST hit the one-active-run gate. NO auto-retry — the composer
+      // offers "interrupt and send" (supersede) instead. #497/S4: adopt the
+      // server's activeRunId as the run-fact so that supersede can TARGET the
+      // (possibly foreign-tab) active run via the CAS, rather than a blind
+      // promote+abort that just 409s again. A stale/absent id keeps the prior fact.
+      return to(m, { name: "error", kind: "run-already-active" }, {
+        ctx: { runFact: event.activeRunId ? { runId: event.activeRunId } : m.ctx.runFact },
+      });
+
+    // ---- lifecycle -----------------------------------------------------
+    case "DISPOSE":
+      // Unmount: abort in-flight controllers, drop timers, and bump the epoch so
+      // NO late callback can drive this (now dead) machine (I5).
+      return command(
+        m,
+        { name: "idle" },
+        [
+          { type: "abortAttach" },
+          { type: "cancelReconnect" },
+          { type: "disarmPoll" },
+        ],
+        { liveFollow: false },
+      );
+
+    default: {
+      // Exhaustiveness guard.
+      const _never: never = event;
+      void _never;
+      return stay(m);
+    }
+  }
+}

apps/client/src/features/ai-chat/types/ai-chat.types.ts

@@ -181,6 +181,12 @@ export interface IAiChatMessageRow {
   toolCalls?: unknown;
   metadata?: {
     parts?: UIMessage["parts"];
+    // #491 step-alignment anchor: the count of FINISHED steps whose parts are in
+    // THIS row, written atomically with `parts` server-side (flushAssistant). The
+    // resume client reads it as its persisted step frontier N — the tail-only
+    // attach asks the run-stream registry for the frames of step N onward (the
+    // seed already carries steps 0..N-1). Absent on pre-#491 rows -> read as 0.
+    stepsPersisted?: number;
     // AI SDK v6 `totalUsage` persisted on assistant rows. Legacy cumulative
     // figure (sum of every step's usage for the turn); kept for back-compat and
     // as the fallback for older rows that have no `contextTokens`.

apps/client/src/features/ai-chat/utils/adopt-chat-id.test.ts

@@ -3,6 +3,7 @@ import {
   resolveAdoptedChatId,
   newlyAddedChatIds,
   extractServerChatId,
+  extractRunId,
 } from "./adopt-chat-id";
 
 describe("resolveAdoptedChatId", () => {
@@ -70,3 +71,17 @@ describe("extractServerChatId", () => {
     expect(extractServerChatId(undefined)).toBeUndefined();
   });
 });
+
+describe("extractRunId", () => {
+  it("reads a string runId from the start metadata", () => {
+    expect(extractRunId({ metadata: { runId: "run-1" } })).toBe("run-1");
+  });
+  it("returns undefined when runId is absent", () => {
+    expect(extractRunId({ metadata: { chatId: "c" } })).toBeUndefined();
+    expect(extractRunId({})).toBeUndefined();
+    expect(extractRunId(undefined)).toBeUndefined();
+  });
+  it("returns undefined for a non-string runId", () => {
+    expect(extractRunId({ metadata: { runId: 7 } })).toBeUndefined();
+  });
+});

apps/client/src/features/ai-chat/utils/adopt-chat-id.ts

@@ -56,6 +56,20 @@ export function extractServerChatId(
   return typeof m?.chatId === "string" ? m.chatId : undefined;
 }
 
+/**
+ * #488: read the authoritative RUN id off a streaming assistant message. The
+ * server attaches it as `message.metadata.runId` on the `start` part when a run
+ * wraps the turn (see server `chatStreamMetadata`, #184/#487). This is the live
+ * run-fact update the client FSM adopts (mirrors `extractServerChatId`). Returns
+ * it only when it is a string; undefined otherwise.
+ */
+export function extractRunId(
+  message: { metadata?: unknown } | undefined,
+): string | undefined {
+  const m = message?.metadata as { runId?: string } | undefined;
+  return typeof m?.runId === "string" ? m.runId : undefined;
+}
+
 /**
  * The deduped set of ids present in `afterIds` but not in `beforeIds`. A
  * paginated/flatMapped list can repeat the same id, so dedupe: one genuinely-new

apps/client/src/features/ai-chat/utils/collapse-blank-lines.test.ts

@@ -33,29 +33,44 @@ describe("collapseBlankLines", () => {
   });
 });
 
-describe("collapseBlankLines + renderChatMarkdown (tight reasoning rendering)", () => {
-  it("renders a blank-line-separated list as a TIGHT list (no <li><p>)", () => {
+describe("collapseBlankLines + renderChatMarkdown (canonical converter)", () => {
+  // Chat markdown now renders through @docmost/prosemirror-markdown (issue #347):
+  // the SAME converter the editor/import use. Its list items are schema-shaped —
+  // each <li>'s content is wrapped in a <p> (listItem content is `paragraph+`) —
+  // so the HTML always carries `<li><p>…</p></li>` regardless of blank-line
+  // looseness in the source (the converter has no tight/loose distinction). The
+  // visual tightness that `collapseBlankLines` used to buy is now provided by
+  // CSS (`.markdown li p { margin: 0 }`), not the HTML shape.
+  it("renders a blank-line-separated bullet list as a real <ul> list", () => {
     const loose =
       "Intro paragraph.\n\n- item one\n\n- item two\n\n- item three";
     const html = renderChatMarkdown(collapseBlankLines(loose), {});
-    // Tight list: each <li> holds the text directly, not wrapped in a <p>.
-    expect(html).toContain("<li>item one</li>");
-    expect(html).not.toContain("<li><p>");
-    // The list still parses as a list after the paragraph (not a paragraph+<br>).
+    // Clean, un-namespaced HTML (DOMSerializer, not XMLSerializer) — no xmlns.
     expect(html).toContain("<ul>");
+    expect(html).not.toMatch(/<ul[^>]*xmlns/);
+    // The item text is present (inside the schema's <li><p> wrapper).
+    expect(html).toContain("item one");
+    // The intro paragraph renders as its own paragraph before the list.
     expect(html).toContain("<p>Intro paragraph.</p>");
   });
 
-  it("renders an ordered list (1. 2.) as tight after collapsing", () => {
+  it("renders an ordered list (1. 2.) as a real <ol> list", () => {
     const loose = "Intro.\n\n1. first\n\n2. second";
     const html = renderChatMarkdown(collapseBlankLines(loose), {});
     expect(html).toContain("<ol>");
-    expect(html).toContain("<li>first</li>");
-    expect(html).not.toContain("<li><p>");
+    expect(html).not.toMatch(/<ol[^>]*xmlns/);
+    expect(html).toContain("first");
+    expect(html).toContain("second");
   });
 
-  it("the loose source WOULD render <li><p> without collapsing (control)", () => {
+  it("wraps list-item content in <p> (schema shape; tightness is CSS)", () => {
+    // The canonical converter always wraps a list item's content in a paragraph,
+    // whether or not the source had blank lines between items.
     const loose = "- a\n\n- b";
     expect(renderChatMarkdown(loose, {})).toContain("<li><p>");
+    // And a "tight" source produces the identical wrapping (no distinction).
+    expect(renderChatMarkdown(collapseBlankLines(loose), {})).toContain(
+      "<li><p>",
+    );
   });
 });

apps/client/src/features/ai-chat/utils/count-stream-tokens.test.ts

@@ -6,10 +6,13 @@ describe("estimateTokens", () => {
     expect(estimateTokens("")).toBe(0);
   });
 
-  it("ceils chars/4 so any non-empty text is at least 1 token", () => {
+  // #490: migrated onto the shared @docmost/token-estimate module (chars/2.5, up
+  // from the old client-only chars/4) so the client counter and the server replay
+  // budgeter can never diverge.
+  it("ceils chars/2.5 so any non-empty text is at least 1 token", () => {
     expect(estimateTokens("a")).toBe(1);
-    expect(estimateTokens("abcd")).toBe(1);
-    expect(estimateTokens("abcde")).toBe(2);
-    expect(estimateTokens("12345678")).toBe(2);
+    expect(estimateTokens("ab")).toBe(1);
+    expect(estimateTokens("abcde")).toBe(2); // 5 / 2.5 = 2
+    expect(estimateTokens("x".repeat(10))).toBe(4); // 10 / 2.5 = 4
   });
 });

apps/client/src/features/ai-chat/utils/count-stream-tokens.ts

@@ -2,18 +2,10 @@
  * Rough client-side token estimation for AI-chat UI affordances.
  *
  * No provider streams exact per-token usage mid-stream, so any in-flight figure
- * is a CLIENT ESTIMATE (chars/≈4 heuristic). Pure + unit-testable: it never runs
- * a real BPE tokenizer (that would be O(n²) on the hot path, bloat the bundle,
- * and be wrong for Gemini/Ollama anyway). Used by the in-body reasoning counter
- * ("Thinking · N tokens").
+ * is a CLIENT ESTIMATE. This re-exports the SHARED estimator from
+ * `@docmost/token-estimate` (chars/2.5) so the in-body counter and the server's
+ * replay budgeter use the SAME heuristic — two divergent estimators would mean
+ * "the badge shows 60%" while "the budgeter already trimmed" (#490). Used by the
+ * in-body reasoning counter ("Thinking · N tokens").
  */
-
-/**
- * Rough token estimate for a piece of text using the standard chars/≈4 heuristic.
- * Returns 0 for empty/whitespace-free-of-content input, and ceils so any
- * non-empty text counts as at least one token.
- */
-export function estimateTokens(text: string): number {
-  if (!text) return 0;
-  return Math.ceil(text.length / 4);
-}
+export { estimateTokens } from "@docmost/token-estimate";

apps/client/src/features/ai-chat/utils/error-message.test.ts

@@ -23,6 +23,89 @@ describe("describeChatError", () => {
     });
   });
 
+  it("classifies an A_RUN_BEGIN_FAILED 503 as a temporary run-start failure, NOT provider-not-configured (#486)", () => {
+    // The FULL real body the server writes for a beginRun failure: a
+    // ServiceUnavailableException(object) whose response is serialized verbatim
+    // onto the raw socket, self-describing statusCode 503 + the run-start code.
+    const body =
+      '{"message":"Could not start the agent run. This is usually temporary — please try again.","code":"A_RUN_BEGIN_FAILED","statusCode":503}';
+    expect(describeChatError(body, t)).toEqual({
+      title: "Could not start the run",
+      detail:
+        "The agent run could not be started. This is usually temporary — please try again.",
+    });
+    // ORDER GUARD: even though the body ALSO carries statusCode 503 (which the
+    // generic branch matches), the A_RUN_BEGIN_FAILED branch runs first, so it is
+    // never mislabeled "AI provider not configured".
+    expect(describeChatError(body, t).title).not.toBe(
+      "AI provider not configured",
+    );
+  });
+
+  // #488 commit 5: the #487 concurrency-gate / supersede 409s. FULL real bodies:
+  // a ConflictException(object) whose response is serialized verbatim, carrying a
+  // `code` and statusCode 409. Each must classify to a human text, not raw JSON.
+  it("classifies A_RUN_ALREADY_ACTIVE (409) as already-answering, not raw JSON", () => {
+    const body =
+      '{"message":"A run is already active for this chat","code":"A_RUN_ALREADY_ACTIVE","statusCode":409}';
+    expect(describeChatError(body, t).title).toBe(
+      "The agent is already answering",
+    );
+    // Never leaks the raw code as the detail.
+    expect(describeChatError(body, t).detail).not.toContain("A_RUN_ALREADY_ACTIVE");
+  });
+
+  it("classifies SUPERSEDE_TARGET_MISMATCH (409) as run-changed", () => {
+    // Real server body shape: the current run id is `activeRunId` (NOT `runId`) —
+    // see ai-chat.controller.ts. describeChatError classifies off `code` only.
+    const body =
+      '{"message":"active run does not match the supersede target","code":"SUPERSEDE_TARGET_MISMATCH","activeRunId":"run-x","statusCode":409}';
+    expect(describeChatError(body, t).title).toBe(
+      "Couldn't interrupt — the run changed",
+    );
+  });
+
+  it("classifies SUPERSEDE_TIMEOUT (409) as couldn't-interrupt-in-time", () => {
+    const body =
+      '{"message":"the run did not settle within the supersede window","code":"SUPERSEDE_TIMEOUT","statusCode":409}';
+    expect(describeChatError(body, t).title).toBe("Couldn't interrupt in time");
+  });
+
+  it("classifies SUPERSEDE_INVALID (409) as couldn't-interrupt-that-run", () => {
+    const body =
+      '{"message":"supervise requires chatId","code":"SUPERSEDE_INVALID","statusCode":409}';
+    expect(describeChatError(body, t).title).toBe(
+      "Couldn't interrupt that run",
+    );
+  });
+
+  it("ORDER GUARD: A_RUN_ALREADY_ACTIVE wins over any generic status branch", () => {
+    // Even though the body could superficially look 4xx-ish, the code branch runs
+    // first, so it is never mislabeled by a generic status heading.
+    const body =
+      '{"message":"conflict","code":"A_RUN_ALREADY_ACTIVE","statusCode":409}';
+    const view = describeChatError(body, t);
+    expect(view.title).not.toBe("Something went wrong");
+    expect(view.title).not.toBe("AI provider not configured");
+  });
+
+  it("classifies a token-degeneration abort under the SAME 'Response stopped.' marker the live view shows (#495)", () => {
+    // The exact reason the server persists in metadata.error on a degeneration
+    // abort (ai-chat.service OUTPUT_DEGENERATION_ERROR). Live, this event shows
+    // the neutral "Response stopped." notice; the persisted banner MUST match it
+    // so live and refetch never disagree.
+    const view = describeChatError(
+      "Output degeneration detected (repeated token loop)",
+      t,
+    );
+    expect(view.title).toBe("Response stopped.");
+    expect(view.detail).toBe(
+      "The answer was stopped automatically because the model fell into a repeated output loop.",
+    );
+    // Regression guard: it must NOT fall through to the generic heading.
+    expect(view.title).not.toBe("Something went wrong");
+  });
+
   it("classifies a dropped connection (ECONNRESET) as a lost-connection error", () => {
     expect(
       describeChatError("Cannot connect to API: read ECONNRESET", t).title,

apps/client/src/features/ai-chat/utils/error-message.ts

@@ -24,6 +24,75 @@ export function describeChatError(
 ): ChatErrorView {
   const msg = message ?? "";
 
+  // Our own "could not start the run" gate (A_RUN_BEGIN_FAILED, #486): a 503
+  // whose body carries this code is a TEMPORARY server-side failure while
+  // starting the run (e.g. a DB-pool blip), NOT an unconfigured provider. It MUST
+  // be matched STRICTLY BEFORE the generic 503 branch below, which would
+  // otherwise mislabel it "The AI provider is not configured" and tell the user
+  // to call an admin instead of just retrying.
+  if (/"code"\s*:\s*"A_RUN_BEGIN_FAILED"/.test(msg)) {
+    return {
+      title: t("Could not start the run"),
+      detail: t(
+        "The agent run could not be started. This is usually temporary — please try again.",
+      ),
+    };
+  }
+
+  // #488 commit 5: the #487 concurrency-gate / supersede 409s. These arrive as a
+  // ConflictException(object) body carrying a `code` (and statusCode 409). They
+  // MUST be classified by `code` STRICTLY BEFORE any generic status branch, or the
+  // user sees the raw JSON `{"code":"A_RUN_ALREADY_ACTIVE",…}`. The code strings
+  // are the real #487 server contract (ai-chat.controller.ts) — do not invent.
+  if (/"code"\s*:\s*"A_RUN_ALREADY_ACTIVE"/.test(msg)) {
+    return {
+      title: t("The agent is already answering"),
+      detail: t(
+        "This chat already has a run in progress. Wait for it to finish, or interrupt it and send now.",
+      ),
+    };
+  }
+  if (/"code"\s*:\s*"SUPERSEDE_TARGET_MISMATCH"/.test(msg)) {
+    return {
+      title: t("Couldn't interrupt — the run changed"),
+      detail: t(
+        "The run you tried to interrupt is no longer the active one. Check the latest answer and try again.",
+      ),
+    };
+  }
+  if (/"code"\s*:\s*"SUPERSEDE_TIMEOUT"/.test(msg)) {
+    return {
+      title: t("Couldn't interrupt in time"),
+      detail: t(
+        "The previous run didn't stop in time. Nothing was sent — try sending again.",
+      ),
+    };
+  }
+  if (/"code"\s*:\s*"SUPERSEDE_INVALID"/.test(msg)) {
+    return {
+      title: t("Couldn't interrupt that run"),
+      detail: t(
+        "The run to interrupt doesn't belong to this chat. Reload and try again.",
+      ),
+    };
+  }
+
+  // Our own token-degeneration abort (#444): the server aborts a runaway
+  // repetition loop and persists this exact reason in metadata.error. LIVE, the
+  // same abort surfaces as the neutral "Response stopped." notice (the client
+  // cannot tell it from a manual Stop mid-stream), so the persisted banner must
+  // read the SAME "Response stopped." marker — otherwise the live view and a
+  // later refetch show two different texts for one event. The detail explains the
+  // loop-guard cause without contradicting the shared heading.
+  if (/output degeneration detected|repeated token loop/i.test(msg)) {
+    return {
+      title: t("Response stopped."),
+      detail: t(
+        "The answer was stopped automatically because the model fell into a repeated output loop.",
+      ),
+    };
+  }
+
   if (/"statusCode"\s*:\s*403\b/.test(msg)) {
     return {
       title: t("AI chat is disabled"),

apps/client/src/features/ai-chat/utils/markdown.ts

@@ -1,6 +1,37 @@
-import { markdownToHtml } from "@docmost/editor-ext";
+import {
+  markdownToProseMirrorSync,
+  docmostExtensions,
+} from "@docmost/prosemirror-markdown/browser";
+import { getSchema } from "@tiptap/core";
+import { Node as PMNode, DOMSerializer } from "@tiptap/pm/model";
 import DOMPurify from "dompurify";
 
+// The Docmost editor schema, built once. Chat markdown is rendered through the
+// SAME schema the editor/import use (issue #347), so chat output matches how the
+// page would render the same markdown.
+const chatSchema = getSchema(docmostExtensions);
+
+/**
+ * Markdown -> HTML for chat display, via the canonical converter. We serialize
+ * the ProseMirror doc with `DOMSerializer` into a real element and read its
+ * `innerHTML` (rather than `@tiptap/html`'s `generateHTML`, whose browser path
+ * uses `XMLSerializer` and stamps a `xmlns` on every block) so the markup is
+ * clean HTML. `li > p` wrapping is inherent to the schema (listItem content is
+ * `paragraph+`); the chat CSS zeroes those paragraph margins so lists still
+ * render tight.
+ */
+function markdownToChatHtml(markdown: string): string {
+  const doc = markdownToProseMirrorSync(markdown);
+  const node = PMNode.fromJSON(chatSchema, doc);
+  const div = document.createElement("div");
+  DOMSerializer.fromSchema(chatSchema).serializeFragment(
+    node.content,
+    { document },
+    div,
+  );
+  return div.innerHTML;
+}
+
 export interface RenderChatMarkdownOptions {
   /**
    * Neutralize INTERNAL links so they render as inert text (no `href`/`target`).
@@ -63,22 +94,32 @@ function neutralizeInternalLinksHook(node: Element): void {
 
 /**
  * Render AI markdown to sanitized HTML for read-only display. We reuse the
- * app's `markdownToHtml` (the same `marked` pipeline used for paste/import) so
- * chat output matches the editor's markdown flavor, then sanitize with
- * DOMPurify — LLM output is untrusted, so it must never reach the DOM unsanitized.
+ * canonical converter (issue #347): markdown -> ProseMirror JSON (the SAME
+ * `markdownToProseMirrorSync` the editor paste/import path uses, so chat output
+ * matches the editor's markdown flavor) -> HTML via `markdownToChatHtml`
+ * (DOMSerializer), then sanitize with DOMPurify — LLM output is untrusted, so it
+ * must never reach the DOM unsanitized.
  *
- * `markdownToHtml` can return `string | Promise<string>` (it has async marked
- * extensions registered). In practice plain chat markdown resolves
- * synchronously, but we guard the Promise case by returning a safe empty string
- * for that branch (the caller renders the raw text fallback instead).
+ * Stays SYNCHRONOUS: both callers render inside React (a memo and a useMemo),
+ * so the whole pipeline must resolve without awaiting. The converter's sync
+ * entry makes that possible; on any conversion error we return "" so the caller
+ * falls back to raw text (the same fallback the old Promise-guard produced).
  */
 export function renderChatMarkdown(
   markdown: string,
   options: RenderChatMarkdownOptions = {},
 ): string {
   if (!markdown) return "";
-  const html = markdownToHtml(markdown);
-  if (typeof html !== "string") return "";
+  let html: string;
+  try {
+    // markdown -> canonical PM JSON -> HTML (native DOMParser in the browser;
+    // jsdom is never bundled — see @docmost/prosemirror-markdown/browser).
+    html = markdownToChatHtml(markdown);
+  } catch {
+    // Malformed/unsupported markdown must not crash the chat render; fall back
+    // to raw text (empty return -> caller shows the plain-text branch).
+    return "";
+  }
 
   if (!options.neutralizeInternalLinks) {
     // Internal chat: unchanged behavior, no hook registered.

apps/client/src/features/ai-chat/utils/resume-helpers.test.ts

@@ -4,7 +4,8 @@ import type { IAiChatMessageRow } from "@/features/ai-chat/types/ai-chat.types.t
 import {
   isStreamingTail,
   isSettledAssistantTail,
-  seedRows,
+  stepsPersistedOf,
+  mergeDeltaRowsIntoPages,
   mergeById,
 } from "./resume-helpers.ts";
 
@@ -12,8 +13,18 @@ function row(
   id: string,
   role: string,
   status?: string,
+  stepsPersisted?: number,
 ): IAiChatMessageRow {
-  return { id, role, content: "", status, createdAt: "2026-01-01T00:00:00Z" };
+  return {
+    id,
+    role,
+    content: "",
+    status,
+    createdAt: "2026-01-01T00:00:00Z",
+    ...(stepsPersisted !== undefined
+      ? { metadata: { stepsPersisted } }
+      : {}),
+  };
 }
 
 function makeMsg(id: string, text: string): UIMessage {
@@ -65,23 +76,92 @@ describe("isSettledAssistantTail", () => {
   });
 });
 
-describe("seedRows", () => {
-  const rows = [row("u1", "user"), row("a1", "assistant", "streaming")];
-
-  it("returns the rows unchanged when not stripping", () => {
-    expect(seedRows(rows, false)).toBe(rows);
+describe("stepsPersistedOf", () => {
+  it("reads metadata.stepsPersisted", () => {
+    expect(stepsPersistedOf(row("a1", "assistant", "streaming", 3))).toBe(3);
+    expect(stepsPersistedOf(row("a1", "assistant", "streaming", 0))).toBe(0);
   });
 
-  it("drops the last row when stripping", () => {
-    const seeded = seedRows(rows, true);
-    expect(seeded).toHaveLength(1);
-    expect(seeded[0].id).toBe("u1");
+  it("defaults to 0 for a pre-#491 row (absent), null/undefined, or a bad value", () => {
+    expect(stepsPersistedOf(row("a1", "assistant", "streaming"))).toBe(0);
+    expect(stepsPersistedOf(null)).toBe(0);
+    expect(stepsPersistedOf(undefined)).toBe(0);
+    expect(
+      stepsPersistedOf({
+        id: "a1",
+        role: "assistant",
+        content: "",
+        createdAt: "x",
+        metadata: { stepsPersisted: -2 },
+      }),
+    ).toBe(0);
   });
 
-  it("returns an empty list when stripping a single-row list", () => {
-    expect(seedRows([row("a1", "assistant", "streaming")], true)).toHaveLength(
-      0,
-    );
+  it("floors a non-integer count", () => {
+    expect(
+      stepsPersistedOf({
+        id: "a1",
+        role: "assistant",
+        content: "",
+        createdAt: "x",
+        metadata: { stepsPersisted: 2.9 },
+      }),
+    ).toBe(2);
+  });
+});
+
+describe("mergeDeltaRowsIntoPages", () => {
+  const pages = () => [
+    { items: [row("u1", "user"), row("a1", "assistant", "streaming", 1)], meta: {} },
+  ];
+
+  it("returns the pages unchanged for an empty delta", () => {
+    const p = pages();
+    expect(mergeDeltaRowsIntoPages(p, [])).toBe(p);
+  });
+
+  it("appends a genuinely new row to the last page in chronological order", () => {
+    const merged = mergeDeltaRowsIntoPages(pages(), [row("a2", "assistant", "streaming", 0)]);
+    expect(merged[0].items.map((i) => i.id)).toEqual(["u1", "a1", "a2"]);
+  });
+
+  it("replaces a grown row in place (per-step growth), never appends a duplicate", () => {
+    const merged = mergeDeltaRowsIntoPages(pages(), [
+      row("a1", "assistant", "streaming", 2),
+    ]);
+    expect(merged[0].items.map((i) => i.id)).toEqual(["u1", "a1"]);
+    // the in-place replacement carries the grown step frontier.
+    expect(stepsPersistedOf(merged[0].items[1])).toBe(2);
+  });
+
+  it("does not mutate the input pages", () => {
+    const input = pages();
+    const before = input[0].items.slice();
+    mergeDeltaRowsIntoPages(input, [row("a2", "assistant", "streaming", 0)]);
+    expect(input[0].items).toEqual(before); // untouched
+  });
+
+  // #491 CONTRACT: the delta overlap window re-delivers the same rows, so merging
+  // MUST be idempotent — applying a delta twice equals applying it once (no growth,
+  // no reorder). A regression re-introduces duplicate assistant bubbles per poll.
+  it("is idempotent: applying the same delta twice equals once", () => {
+    const delta = [
+      row("a1", "assistant", "streaming", 2), // grown existing row
+      row("a2", "assistant", "streaming", 0), // new row
+    ];
+    const once = mergeDeltaRowsIntoPages(pages(), delta);
+    const twice = mergeDeltaRowsIntoPages(once, delta);
+    const thrice = mergeDeltaRowsIntoPages(twice, delta);
+    expect(once[0].items.map((i) => i.id)).toEqual(["u1", "a1", "a2"]);
+    expect(twice[0].items.map((i) => i.id)).toEqual(["u1", "a1", "a2"]);
+    expect(twice).toEqual(once);
+    expect(thrice).toEqual(once);
+  });
+
+  it("seeds a first page when the cache is empty", () => {
+    const merged = mergeDeltaRowsIntoPages([], [row("u1", "user")]);
+    expect(merged).toHaveLength(1);
+    expect(merged[0].items.map((i) => i.id)).toEqual(["u1"]);
   });
 });
 
@@ -109,4 +189,37 @@ describe("mergeById", () => {
     expect(mergeById(prev, null)).toBe(prev);
     expect(mergeById(prev, undefined)).toBe(prev);
   });
+
+  // #491 CONTRACT: the delta poll's overlap window GUARANTEES the same row is
+  // re-delivered across close polls, so merging must be IDEMPOTENT by id — merging
+  // the same row (or an equal-length list of rows) twice must not duplicate or
+  // reorder. This is the property the whole delta-poll design leans on; a
+  // regression here would re-introduce duplicate assistant bubbles on every poll.
+  it("is idempotent by id: re-merging the same row does not duplicate or reorder", () => {
+    const seed = [makeMsg("u1", "hi"), makeMsg("a1", "step 1")];
+    const repeat = makeMsg("a1", "step 1"); // the SAME row the overlap re-delivers
+    const once = mergeById(seed, repeat);
+    const twice = mergeById(once, repeat);
+    const thrice = mergeById(twice, repeat);
+    // Length is stable (no growth), order is stable (user then assistant).
+    expect(once.map((m) => m.id)).toEqual(["u1", "a1"]);
+    expect(twice.map((m) => m.id)).toEqual(["u1", "a1"]);
+    expect(thrice.map((m) => m.id)).toEqual(["u1", "a1"]);
+    // The repeated merge converges: the row is replaced in place, never appended.
+    expect(twice[1]).toBe(repeat);
+  });
+
+  it("is idempotent across a batch of repeated + grown rows (delta re-delivery)", () => {
+    // A delta poll re-delivers a1 (unchanged) and a2 (grown one step). Applying the
+    // batch twice must equal applying it once — the poll can re-send either.
+    const start = [makeMsg("u1", "hi"), makeMsg("a1", "done")];
+    const batch = [makeMsg("a1", "done"), makeMsg("a2", "grown step 2")];
+    const apply = (list: typeof start) =>
+      batch.reduce((acc, row) => mergeById(acc, row), list);
+    const once = apply(start);
+    const twice = apply(once);
+    expect(once.map((m) => m.id)).toEqual(["u1", "a1", "a2"]);
+    expect(twice.map((m) => m.id)).toEqual(["u1", "a1", "a2"]);
+    expect(twice).toEqual(once);
+  });
 });

apps/client/src/features/ai-chat/utils/resume-helpers.ts

@@ -11,9 +11,10 @@ import type { IAiChatMessageRow } from "@/features/ai-chat/types/ai-chat.types.t
 
 /**
  * A STREAMING tail: the last persisted row is an assistant row still marked
- * `status === 'streaming'`. Such a tail is stripped from the seed and rebuilt by
- * the replay (`expect=live`), since the SDK's `text-start` always pushes a new
- * part and replaying over a seeded in-progress row would duplicate its text.
+ * `status === 'streaming'`. #491 (tail-only): such a tail is seeded UNCHANGED —
+ * it carries the persisted steps 0..N-1 — and the run-stream registry's tail
+ * (frames for steps >= N) is APPENDED to it by the SDK's `readUIMessageStream`
+ * continuation. Only the presence of this tail decides WHETHER to attach.
  */
 export function isStreamingTail(rows: IAiChatMessageRow[]): boolean {
   const tail = rows[rows.length - 1];
@@ -32,15 +33,61 @@ export function isSettledAssistantTail(rows: IAiChatMessageRow[]): boolean {
 }
 
 /**
- * Seed rows for `useChat`: return the rows unchanged, or without the last row when
- * `strip` is set (the streaming tail is stripped so the live replay rebuilds it
- * without duplicating parts).
+ * #491 tail-only anchor: the count of FINISHED steps whose parts are persisted in
+ * THIS assistant row (`metadata.stepsPersisted`), written atomically with `parts`
+ * server-side. The resume client reads it as its persisted step frontier N — the
+ * tail-only attach asks the run-stream registry for the frames of step N onward
+ * (the seed already carries steps 0..N-1). Absent on pre-#491 rows => 0.
  */
-export function seedRows(
+export function stepsPersistedOf(
+  row: IAiChatMessageRow | null | undefined,
+): number {
+  const n = row?.metadata?.stepsPersisted;
+  return typeof n === "number" && n >= 0 ? Math.floor(n) : 0;
+}
+
+/** One page of the messages infinite-query cache (`{ items, meta }`). */
+export interface IMessagePage {
+  items: IAiChatMessageRow[];
+  meta: unknown;
+}
+
+/**
+ * #491 delta-poll merge: upsert the delta poll's `rows` into the messages
+ * infinite-query page structure IDEMPOTENTLY by id. The delta endpoint's overlap
+ * window GUARANTEES occasional REPEATS, so this MUST converge: a row already
+ * present is REPLACED IN PLACE (per-step growth of an in-progress row), a new row
+ * is APPENDED to the last page in chronological order (the server returns delta
+ * rows oldest-first). Applying the same delta twice equals applying it once. Never
+ * mutates the input pages (returns fresh page objects with cloned item arrays).
+ */
+export function mergeDeltaRowsIntoPages(
+  pages: IMessagePage[],
   rows: IAiChatMessageRow[],
-  strip: boolean,
-): IAiChatMessageRow[] {
-  return strip ? rows.slice(0, -1) : rows;
+): IMessagePage[] {
+  if (rows.length === 0) return pages;
+  const next: IMessagePage[] = pages.map((p) => ({
+    ...p,
+    items: p.items.slice(),
+  }));
+  const locate = (id: string): [number, number] | null => {
+    for (let pi = 0; pi < next.length; pi++) {
+      const ii = next[pi].items.findIndex((it) => it.id === id);
+      if (ii !== -1) return [pi, ii];
+    }
+    return null;
+  };
+  for (const row of rows) {
+    const at = locate(row.id);
+    if (at) {
+      next[at[0]].items[at[1]] = row; // replace in place — idempotent by id
+    } else if (next.length > 0) {
+      next[next.length - 1].items.push(row); // append chronologically
+    } else {
+      next.push({ items: [row], meta: undefined });
+    }
+  }
+  return next;
 }
 
 /**

apps/client/src/features/ai-chat/utils/sdk-continuation-tripwire.test.ts

@@ -0,0 +1,83 @@
+import { describe, it, expect } from "vitest";
+import { readUIMessageStream, type UIMessage } from "ai";
+import pkg from "../../../../package.json";
+
+/**
+ * PIN-SPEC TRIP-WIRE (#491). The tail-only attach continuation relies on THREE
+ * behaviors of `ai@6.0.207`, verified line-by-line in the issue. Without this
+ * test, an `ai` bump could silently break attach (the client would append the
+ * live tail to the wrong message, or duplicate a step):
+ *
+ *   1. `readUIMessageStream({ message })` CONTINUES the passed message — it does
+ *      not start a fresh one — so the tail streamed after a re-seed is appended to
+ *      the seeded assistant row (the same DB id).
+ *   2. A `start` frame does NOT reset the existing message's parts (so the seeded
+ *      steps 0..N-1 survive; the synthetic `start` the registry prepends only
+ *      carries the run-fact metadata).
+ *   3. Text parts do NOT cross a `finish-step` boundary — a new `text-start` after
+ *      `finish-step` is a NEW part — so the reconstructed steps stay separated and
+ *      the step frontier stays meaningful.
+ *
+ * If an `ai` upgrade changes any of these, this test fails LOUD instead of the
+ * resume path silently corrupting.
+ */
+describe("ai SDK continuation trip-wire (#491, tail-only attach)", () => {
+  it("is pinned to the exact ai version the continuation was verified against", () => {
+    // A caret/range bump is exactly what would silently break attach — require an
+    // exact pin. Bumping ai MUST re-verify the behavior asserted below, then this.
+    expect((pkg as { dependencies: Record<string, string> }).dependencies.ai).toBe(
+      "6.0.207",
+    );
+  });
+
+  it("continues the seeded message: start does not reset parts, the tail appends as new parts", async () => {
+    // A seeded assistant row with ONE finished step already reconstructed.
+    const seeded: UIMessage = {
+      id: "assistant-1",
+      role: "assistant",
+      parts: [
+        { type: "step-start" },
+        { type: "text", text: "STEP0", state: "done" },
+      ],
+    } as UIMessage;
+
+    // The tail the registry delivers on re-attach: a synthetic start (run-fact),
+    // then step 1's frames, then finish. As UI-message chunks (what the SSE frames
+    // decode to).
+    const chunks = [
+      { type: "start", messageMetadata: { runId: "r1", chatId: "c1" } },
+      { type: "start-step" },
+      { type: "text-start", id: "t1" },
+      { type: "text-delta", id: "t1", delta: "STEP1" },
+      { type: "text-end", id: "t1" },
+      { type: "finish-step" },
+      { type: "finish" },
+    ];
+    const stream = new ReadableStream({
+      start(c) {
+        for (const ch of chunks) c.enqueue(ch);
+        c.close();
+      },
+    });
+
+    let last: UIMessage | undefined;
+    for await (const msg of readUIMessageStream({ message: seeded, stream })) {
+      last = msg;
+    }
+
+    expect(last).toBeDefined();
+    // Same message id (continuation, not a fresh message).
+    expect(last!.id).toBe("assistant-1");
+    // The seeded step-0 parts SURVIVED the `start` frame, and step 1 was appended
+    // as SEPARATE parts (text did not cross the finish-step boundary).
+    const shape = last!.parts.map((p) => `${p.type}:${(p as { text?: string }).text ?? ""}`);
+    expect(shape).toEqual([
+      "step-start:",
+      "text:STEP0",
+      "step-start:",
+      "text:STEP1",
+    ]);
+    // The run-fact metadata from the synthetic start frame is applied.
+    expect(last!.metadata).toMatchObject({ runId: "r1", chatId: "c1" });
+  });
+});

apps/client/src/features/comment/components/comment-list-with-tabs.test.tsx

@@ -27,11 +27,15 @@ vi.mock("@/features/space/queries/space-query.ts", () => ({
 import {
   buildChildrenByParent,
   CommentEditorWithActions,
+  sortResolvedByResolvedAt,
 } from "./comment-list-with-tabs";
 
 const c = (id: string, parentCommentId: string | null = null): IComment =>
   ({ id, parentCommentId }) as IComment;
 
+const resolvedAtComment = (id: string, resolvedAt: unknown): IComment =>
+  ({ id, resolvedAt }) as unknown as IComment;
+
 describe("buildChildrenByParent (childrenByParent grouping)", () => {
   it("returns an empty map for undefined or empty input", () => {
     expect(buildChildrenByParent(undefined).size).toBe(0);
@@ -71,6 +75,48 @@ describe("buildChildrenByParent (childrenByParent grouping)", () => {
   });
 });
 
+describe("sortResolvedByResolvedAt (Resolved tab order, #542)", () => {
+  it("orders by resolvedAt DESC — newest resolve first — with ISO-STRING values", () => {
+    // At runtime resolvedAt is an ISO string (axios JSON / WS subscription), so
+    // the sort must coerce with new Date(...) before .getTime().
+    const older = resolvedAtComment("older", "2026-07-10T10:00:00.000Z");
+    const newest = resolvedAtComment("newest", "2026-07-12T10:00:00.000Z");
+    const middle = resolvedAtComment("middle", "2026-07-11T10:00:00.000Z");
+
+    const out = sortResolvedByResolvedAt([older, newest, middle]);
+    expect(out.map((x) => x.id)).toEqual(["newest", "middle", "older"]);
+  });
+
+  it("also handles Date instances (optimistic onMutate window)", () => {
+    const older = resolvedAtComment("older", new Date("2026-01-01T00:00:00Z"));
+    const newer = resolvedAtComment("newer", new Date("2026-06-01T00:00:00Z"));
+    expect(sortResolvedByResolvedAt([older, newer]).map((x) => x.id)).toEqual([
+      "newer",
+      "older",
+    ]);
+  });
+
+  it("does not mutate the input array", () => {
+    const a = resolvedAtComment("a", "2026-01-01T00:00:00.000Z");
+    const b = resolvedAtComment("b", "2026-02-01T00:00:00.000Z");
+    const input = [a, b];
+    sortResolvedByResolvedAt(input);
+    expect(input.map((x) => x.id)).toEqual(["a", "b"]);
+  });
+
+  it("keeps stable order for equal resolvedAt timestamps", () => {
+    const ts = "2026-03-03T03:03:03.000Z";
+    const x = resolvedAtComment("x", ts);
+    const y = resolvedAtComment("y", ts);
+    const z = resolvedAtComment("z", ts);
+    expect(sortResolvedByResolvedAt([x, y, z]).map((c) => c.id)).toEqual([
+      "x",
+      "y",
+      "z",
+    ]);
+  });
+});
+
 function renderReplyEditor() {
   return render(
     <MantineProvider>

apps/client/src/features/comment/components/comment-list-with-tabs.tsx

@@ -53,6 +53,22 @@ export function buildChildrenByParent(
   return m;
 }
 
+// Sort the Resolved tab by resolve time, newest first, on a COPY (never mutate
+// the react-query cache array). `resolvedAt` is typed `Date` but at runtime it
+// is an ISO STRING (from the axios-JSON onSuccess and the WS subscription) — a
+// real Date only during the optimistic onMutate window — so it MUST be coerced
+// with `new Date(...)` before `.getTime()`, or a raw `.getTime()` on the string
+// throws / yields NaN. ES2019's stable sort preserves order for equal
+// timestamps. Callers pass a list already filtered to a truthy `resolvedAt`, so
+// the non-null assertion is safe.
+// Exported for unit testing.
+export function sortResolvedByResolvedAt(resolved: IComment[]): IComment[] {
+  return [...resolved].sort(
+    (a, b) =>
+      new Date(b.resolvedAt!).getTime() - new Date(a.resolvedAt!).getTime(),
+  );
+}
+
 function CommentListWithTabs({ onClose }: CommentListWithTabsProps) {
   const { t } = useTranslation();
   const { pageSlug } = useParams();
@@ -91,7 +107,10 @@ function CommentListWithTabs({ onClose }: CommentListWithTabsProps) {
       (comment: IComment) => comment.resolvedAt,
     );
 
-    return { activeComments: active, resolvedComments: resolved };
+    return {
+      activeComments: active,
+      resolvedComments: sortResolvedByResolvedAt(resolved),
+    };
   }, [comments]);
 
   // Index replies by their parent once, instead of an O(n^2) filter per thread.

apps/client/src/features/comment/queries/comment-query.resolve-undo.test.tsx

@@ -0,0 +1,353 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import React from "react";
+import { renderHook, waitFor } from "@testing-library/react";
+import {
+  QueryClient,
+  QueryClientProvider,
+  InfiniteData,
+} from "@tanstack/react-query";
+
+/**
+ * Coverage for the resolve/reopen mutation (#542): the Undo-in-toast reopen and
+ * its double-click guard, the terminal 404 branch (drop from cache + clear the
+ * inline mark, no rollback), and the directional error copy.
+ */
+
+// A fake TipTap editor injected via the mocked pageEditorAtom, so we can assert
+// the mutation clears the inline comment mark (unsetComment / setCommentResolved).
+const editorMock = vi.hoisted(() => ({
+  current: {
+    isDestroyed: false,
+    commands: { unsetComment: vi.fn(), setCommentResolved: vi.fn() },
+  } as {
+    isDestroyed: boolean;
+    commands: {
+      unsetComment: (id: string) => void;
+      setCommentResolved: (id: string, v: boolean) => void;
+    };
+  } | null,
+}));
+
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: vi.fn(), hide: vi.fn() },
+}));
+
+vi.mock("jotai", () => ({
+  atom: (v: unknown) => v,
+  useAtomValue: () => editorMock.current,
+}));
+
+vi.mock("@/features/comment/services/comment-service", () => ({
+  applySuggestion: vi.fn(),
+  dismissSuggestion: vi.fn(),
+  createComment: vi.fn(),
+  updateComment: vi.fn(),
+  deleteComment: vi.fn(),
+  resolveComment: vi.fn(),
+  getPageComments: vi.fn(),
+}));
+
+import { notifications } from "@mantine/notifications";
+import { resolveComment } from "@/features/comment/services/comment-service";
+import {
+  useResolveCommentMutation,
+  RESOLVE_UNDO_AUTOCLOSE_MS,
+  RQ_KEY,
+} from "@/features/comment/queries/comment-query";
+import { IComment } from "@/features/comment/types/comment.types";
+
+const PAGE_ID = "page-1";
+
+function seededClient(comment: IComment) {
+  const queryClient = new QueryClient({
+    defaultOptions: { mutations: { retry: false } },
+  });
+  const seed: InfiniteData<any> = {
+    pageParams: [undefined],
+    pages: [
+      { items: [comment], meta: { hasNextPage: false, nextCursor: null } },
+    ],
+  };
+  queryClient.setQueryData(RQ_KEY(PAGE_ID), seed);
+  const wrapper = ({ children }: { children: React.ReactNode }) => (
+    <QueryClientProvider client={queryClient}>{children}</QueryClientProvider>
+  );
+  return { queryClient, wrapper };
+}
+
+function items(queryClient: QueryClient): IComment[] {
+  const cache = queryClient.getQueryData(RQ_KEY(PAGE_ID)) as
+    | InfiniteData<any>
+    | undefined;
+  return cache?.pages.flatMap((p) => p.items) ?? [];
+}
+
+const comment = (over?: Partial<IComment>): IComment =>
+  ({
+    id: "c-1",
+    pageId: PAGE_ID,
+    content: "{}",
+    creatorId: "u-1",
+    workspaceId: "ws-1",
+    createdAt: new Date(),
+    resolvedAt: null,
+    ...over,
+  }) as IComment;
+
+// Pull the inline Undo button's onClick out of the success toast's message tree.
+function undoOnClickFromToast(): () => void {
+  const call = vi
+    .mocked(notifications.show)
+    .mock.calls.map((c) => c[0])
+    .find((arg: any) => arg?.autoClose === RESOLVE_UNDO_AUTOCLOSE_MS);
+  expect(call).toBeTruthy();
+  const message: any = (call as any).message;
+  // message = Group( Text, Button ); grab the Button element's onClick.
+  const children = message.props.children as any[];
+  const button = children[1];
+  return button.props.onClick;
+}
+
+describe("useResolveCommentMutation — Undo toast (#542)", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    editorMock.current = {
+      isDestroyed: false,
+      commands: { unsetComment: vi.fn(), setCommentResolved: vi.fn() },
+    };
+  });
+
+  it("resolve shows an Undo toast with autoClose=10000ms; reopen shows NO Undo", async () => {
+    vi.mocked(resolveComment).mockImplementation(async (data) =>
+      comment({
+        resolvedAt: data.resolved ? (new Date() as any) : null,
+      }),
+    );
+    const { wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: true,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    const resolveToast = vi
+      .mocked(notifications.show)
+      .mock.calls.map((c) => c[0])
+      .find((a: any) => a?.autoClose === RESOLVE_UNDO_AUTOCLOSE_MS);
+    expect(resolveToast).toBeTruthy();
+    expect((resolveToast as any).id).toBe("resolve-undo-c-1");
+    expect((resolveToast as any).autoClose).toBe(10000);
+
+    // Now a reopen → plain toast, no autoClose/Undo, no id.
+    vi.clearAllMocks();
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: false,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+    const calls = vi.mocked(notifications.show).mock.calls.map((c) => c[0]);
+    expect(
+      calls.some((a: any) => a?.autoClose === RESOLVE_UNDO_AUTOCLOSE_MS),
+    ).toBe(false);
+    expect(calls).toContainEqual({ message: "Comment re-opened successfully" });
+  });
+
+  it("double/fast Undo click fires reopen EXACTLY once (guard)", async () => {
+    vi.mocked(resolveComment).mockImplementation(async (data) =>
+      comment({ resolvedAt: data.resolved ? (new Date() as any) : null }),
+    );
+    const { wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: true,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    const onClick = undoOnClickFromToast();
+    // Fire twice synchronously (notifications.hide is not synchronous).
+    onClick();
+    onClick();
+
+    await waitFor(() => {
+      const reopenCalls = vi
+        .mocked(resolveComment)
+        .mock.calls.filter(([d]) => d.resolved === false);
+      expect(reopenCalls).toHaveLength(1);
+    });
+    // The mark was cleared once via setCommentResolved(id, false).
+    expect(editorMock.current!.commands.setCommentResolved).toHaveBeenCalledWith(
+      "c-1",
+      false,
+    );
+    // The toast was hidden.
+    expect(notifications.hide).toHaveBeenCalledWith("resolve-undo-c-1");
+  });
+
+  it("404 → drops the comment from cache, clears the inline mark, no rollback, no Undo", async () => {
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 404 } });
+    const { queryClient, wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current
+      .mutateAsync({ commentId: "c-1", pageId: PAGE_ID, resolved: true })
+      .catch(() => undefined);
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    // Removed from cache (NOT rolled back to a phantom).
+    expect(items(queryClient)).toHaveLength(0);
+    // Inline mark cleared via unsetComment (mandatory — no panel row left to do it).
+    expect(editorMock.current!.commands.unsetComment).toHaveBeenCalledWith(
+      "c-1",
+    );
+    // Neutral message, red, and crucially NOT the success copy and NO Undo toast.
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Comment no longer exists",
+      color: "red",
+    });
+    const calls = vi.mocked(notifications.show).mock.calls.map((c) => c[0]);
+    expect(
+      calls.some((a: any) => a?.autoClose === RESOLVE_UNDO_AUTOCLOSE_MS),
+    ).toBe(false);
+  });
+
+  it("404 does not crash when the editor is gone (read-only / panel closed)", async () => {
+    editorMock.current = null;
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 404 } });
+    const { queryClient, wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current
+      .mutateAsync({ commentId: "c-1", pageId: PAGE_ID, resolved: true })
+      .catch(() => undefined);
+    await waitFor(() => expect(result.current.isError).toBe(true));
+    expect(items(queryClient)).toHaveLength(0);
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Comment no longer exists",
+      color: "red",
+    });
+  });
+
+  it("non-404 error on REOPEN shows 'Failed to re-open comment' and rolls back", async () => {
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 500 } });
+    // Seed a RESOLVED comment (the reopen target).
+    const resolved = comment({ resolvedAt: new Date() as any });
+    const { queryClient, wrapper } = seededClient(resolved);
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current
+      .mutateAsync({ commentId: "c-1", pageId: PAGE_ID, resolved: false })
+      .catch(() => undefined);
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Failed to re-open comment",
+      color: "red",
+    });
+    expect(notifications.show).not.toHaveBeenCalledWith(
+      expect.objectContaining({ message: "Failed to resolve comment" }),
+    );
+    // Rolled back: the comment is still present and still resolved.
+    expect(items(queryClient)).toHaveLength(1);
+    expect(items(queryClient)[0].resolvedAt).toBeTruthy();
+  });
+
+  it("reopen via Undo FAILS (non-404) → inline mark is NOT left cleared (doc↔panel stay consistent)", async () => {
+    // First resolve succeeds → produces the Undo toast (no mark change on resolve).
+    vi.mocked(resolveComment).mockResolvedValueOnce(
+      comment({ resolvedAt: new Date() as any }),
+    );
+    const { queryClient, wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: true,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    // Now the reopen fired by Undo fails with a 500.
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 500 } });
+    const onClick = undoOnClickFromToast();
+    onClick();
+
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    // Core F1 guarantee: the mark-clear now lives in the reopen onSuccess, so a
+    // FAILED reopen must never flip the inline mark to unresolved — otherwise the
+    // doc would show an active highlight the panel still treats as resolved and
+    // the collab mark would diverge with nothing committed on the server.
+    expect(
+      editorMock.current!.commands.setCommentResolved,
+    ).not.toHaveBeenCalledWith("c-1", false);
+    // Cache rolled back: the comment stays resolved and present.
+    expect(items(queryClient)).toHaveLength(1);
+    expect(items(queryClient)[0].resolvedAt).toBeTruthy();
+  });
+
+  it("reopen success with a null editorRef degrades gracefully (no throw, no-op)", async () => {
+    // Read-only view / panel closed: pageEditorAtom is null on the success path.
+    editorMock.current = null;
+    vi.mocked(resolveComment).mockResolvedValue(comment({ resolvedAt: null }));
+    const resolved = comment({ resolvedAt: new Date() as any });
+    const { queryClient, wrapper } = seededClient(resolved);
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: false,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    // No crash from the reopen mark-clear; the plain reopen toast is still shown.
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Comment re-opened successfully",
+    });
+    // Cache updated to reopened (resolvedAt cleared by the server payload).
+    expect(items(queryClient)).toHaveLength(1);
+    expect(items(queryClient)[0].resolvedAt).toBeFalsy();
+  });
+
+  it("non-404 error on RESOLVE shows 'Failed to resolve comment' and rolls back", async () => {
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 500 } });
+    const { queryClient, wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current
+      .mutateAsync({ commentId: "c-1", pageId: PAGE_ID, resolved: true })
+      .catch(() => undefined);
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Failed to resolve comment",
+      color: "red",
+    });
+    // Rolled back to open (previousCache), still present.
+    expect(items(queryClient)).toHaveLength(1);
+    expect(items(queryClient)[0].resolvedAt).toBeFalsy();
+  });
+});

apps/client/src/features/comment/queries/comment-query.ts

@@ -20,12 +20,19 @@ import {
   ISuggestionOutcome,
 } from "@/features/comment/types/comment.types";
 import { notifications } from "@mantine/notifications";
+import { Button, Group, Text } from "@mantine/core";
 import { IPagination } from "@/lib/types.ts";
 import { useTranslation } from "react-i18next";
-import { useEffect, useMemo } from "react";
+import React, { useEffect, useMemo, useRef } from "react";
+import { useAtomValue } from "jotai";
+import { pageEditorAtom } from "@/features/editor/atoms/editor-atoms";
 
 export const RQ_KEY = (pageId: string) => ["comments", pageId];
 
+// How long the resolve success toast (with its inline Undo) stays up before it
+// auto-closes. Policy constant — no env override.
+export const RESOLVE_UNDO_AUTOCLOSE_MS = 10000;
+
 export function useCommentsQuery(params: ICommentParams) {
   const query = useInfiniteQuery({
     queryKey: RQ_KEY(params.pageId),
@@ -376,7 +383,25 @@ export function useResolveCommentMutation() {
   const queryClient = useQueryClient();
   const { t } = useTranslation();
 
-  return useMutation({
+  // Keep the live editor in a ref: the toast's Undo (and the 404 branch) must
+  // clear the inline comment mark AFTER the originating CommentListItem has
+  // unmounted (resolving pulls the comment out of the Open list, so its item is
+  // already gone by the time the 10s toast is clicked). In read-only view
+  // pageEditorAtom is null and the mark converges via the server's
+  // COMMENT_MARK_UPDATE job instead.
+  const editor = useAtomValue(pageEditorAtom);
+  const editorRef = useRef(editor);
+  editorRef.current = editor;
+
+  // Self-reference the mutation so the toast's Undo can re-invoke it (reopen)
+  // long after the triggering component unmounted. Declared BEFORE useMutation
+  // and assigned AFTER; the onClick reads mutationRef.current at CALL time, not
+  // definition time, so there is no initialization cycle.
+  const mutationRef = useRef<{
+    mutate: (vars: IResolveComment) => void;
+  } | null>(null);
+
+  const mutation = useMutation({
     mutationFn: (data: IResolveComment) => resolveComment(data),
     onMutate: async (variables) => {
       await queryClient.cancelQueries({ queryKey: RQ_KEY(variables.pageId) });
@@ -401,7 +426,39 @@ export function useResolveCommentMutation() {
 
       return { previousCache };
     },
-    onError: (_err, variables, context) => {
+    onError: (err: any, variables, context) => {
+      // Terminal 404: the comment was really deleted (missing comment or deleted
+      // page — access denial is 403, resolve is idempotent so no 400). Do NOT
+      // roll back (that would resurrect a phantom row in Resolved); instead drop
+      // it from the cache and clear its now-orphaned inline mark. Mirrors
+      // handleDeleteComment and the dismiss-mutation 404 branch.
+      if (err?.response?.status === 404) {
+        const cache = queryClient.getQueryData(RQ_KEY(variables.pageId)) as
+          | InfiniteData<IPagination<IComment>>
+          | undefined;
+        if (cache) {
+          queryClient.setQueryData(
+            RQ_KEY(variables.pageId),
+            removeCommentFromCache(cache, variables.commentId),
+          );
+        }
+        const ed = editorRef.current;
+        if (ed && !ed.isDestroyed) {
+          try {
+            ed.commands.unsetComment(variables.commentId);
+          } catch {
+            /* editor gone / mark already removed */
+          }
+        }
+        notifications.show({
+          message: t("Comment no longer exists"),
+          color: "red",
+        });
+        return;
+      }
+
+      // Generic failure: roll back the optimistic update and show a DIRECTIONAL
+      // error (resolve vs. reopen), not always "resolve".
       if (context?.previousCache) {
         queryClient.setQueryData(
           RQ_KEY(variables.pageId),
@@ -409,7 +466,9 @@ export function useResolveCommentMutation() {
         );
       }
       notifications.show({
-        message: t("Failed to resolve comment"),
+        message: variables.resolved
+          ? t("Failed to resolve comment")
+          : t("Failed to re-open comment"),
         color: "red",
       });
     },
@@ -430,11 +489,72 @@ export function useResolveCommentMutation() {
         );
       }
 
+      // Reopen keeps the plain toast without an Undo.
+      if (!variables.resolved) {
+        // Clear the inline mark ONLY after the server confirms the reopen, so a
+        // failed reopen never leaves an active highlight the panel still treats
+        // as resolved. Mirrors the 404 branch's editor-liveness guard/try-catch.
+        // The button-triggered reopen already set the mark, so this is an
+        // idempotent no-op there.
+        const ed = editorRef.current;
+        if (ed && !ed.isDestroyed) {
+          try {
+            ed.commands.setCommentResolved(variables.commentId, false);
+          } catch {
+            /* editor gone — server COMMENT_MARK_UPDATE converges it */
+          }
+        }
+        notifications.show({ message: t("Comment re-opened successfully") });
+        return;
+      }
+
+      // Resolve: attach an inline Undo (reopen) to the success toast. Built with
+      // React.createElement because this is a .ts module (no JSX).
+      const { commentId, pageId } = variables;
+      const notificationId = `resolve-undo-${commentId}`;
+      // Double-click guard: notifications.hide is NOT synchronous, so the button
+      // stays clickable for a frame or two — without this a fast double-click
+      // would fire reopen twice.
+      let done = false;
       notifications.show({
-        message: variables.resolved
-          ? t("Comment resolved successfully")
-          : t("Comment re-opened successfully"),
+        id: notificationId,
+        autoClose: RESOLVE_UNDO_AUTOCLOSE_MS,
+        message: React.createElement(
+          Group,
+          { justify: "space-between", wrap: "nowrap", gap: "md" },
+          React.createElement(
+            Text,
+            { size: "sm" },
+            t("Comment resolved successfully"),
+          ),
+          React.createElement(
+            Button,
+            {
+              variant: "subtle",
+              size: "compact-sm",
+              onClick: () => {
+                if (done) return;
+                done = true;
+                // Reopen via the SAME mutation (read at click time — the
+                // originating item is already unmounted).
+                mutationRef.current?.mutate({
+                  commentId,
+                  pageId,
+                  resolved: false,
+                });
+                // The inline mark is cleared in the reopen mutation's onSuccess
+                // (bound to server confirmation), NOT here — clearing it eagerly
+                // would desync the doc from the panel if reopen then fails.
+                notifications.hide(notificationId);
+              },
+            },
+            t("Undo"),
+          ),
+        ),
       });
     },
   });
+
+  mutationRef.current = mutation;
+  return mutation;
 }

apps/client/src/features/editor/atoms/editor-atoms.ts

@@ -3,11 +3,20 @@ import { atom } from "jotai";
 // import would drag the whole @tiptap/core engine into the eager graph of every
 // shell component that reads one of these atoms.
 import type { Editor } from "@tiptap/core";
+import type { HocuspocusProvider } from "@hocuspocus/provider";
 import { PageEditMode } from "@/features/user/types/user.types.ts";
 import type { DictationUnavailableReason } from "@/features/dictation/dictation-status";
 
 export const pageEditorAtom = atom<Editor | null>(null);
 
+// #370 — the active page's collab provider, published by the page editor so the
+// header menu can emit the "save-version" stateless signal (Cmd+S / button).
+// Null when the page is read-only / collab isn't connected. A typed initial
+// value (rather than an explicit generic) keeps jotai's overload resolution on
+// the writable PrimitiveAtom branch.
+const initialCollabProvider: HocuspocusProvider | null = null;
+export const collabProviderAtom = atom(initialCollabProvider);
+
 export const titleEditorAtom = atom<Editor | null>(null);
 
 export const readOnlyEditorAtom = atom<Editor | null>(null);

apps/client/src/features/editor/components/fixed-toolbar/use-toolbar-state.test.ts

@@ -0,0 +1,65 @@
+import { describe, it, expect } from "vitest";
+import * as Y from "yjs";
+import { yHistoryAvailability } from "./use-toolbar-state.ts";
+
+// Undo/redo availability is derived from the Yjs UndoManager's PRIVATE
+// `undoStack` / `redoStack` fields (see use-toolbar-state.ts for why we read the
+// stack lengths directly instead of the expensive `editor.can().undo()` dry-run).
+// These tests lock in the behavior AND pin the library shape so a yjs / y-undo
+// upgrade that renames/restructures those internals fails loudly here rather than
+// silently enabling/disabling the toolbar buttons in production.
+describe("yHistoryAvailability", () => {
+  it("reports availability from the stack lengths", () => {
+    expect(yHistoryAvailability({ undoStack: [], redoStack: [] })).toEqual({
+      canUndo: false,
+      canRedo: false,
+    });
+    expect(
+      yHistoryAvailability({ undoStack: [{}], redoStack: [] }),
+    ).toEqual({ canUndo: true, canRedo: false });
+    expect(
+      yHistoryAvailability({ undoStack: [{}], redoStack: [{}, {}] }),
+    ).toEqual({ canUndo: true, canRedo: true });
+  });
+
+  it("returns null when the private stack shape is unrecognized (upgrade guard)", () => {
+    // Simulates a yjs / y-undo upgrade that renames or restructures the private
+    // fields: the caller then falls back to the safe prosemirror-history default
+    // instead of throwing on `.length` of undefined or reading garbage.
+    expect(yHistoryAvailability(undefined)).toBeNull();
+    expect(yHistoryAvailability(null)).toBeNull();
+    expect(yHistoryAvailability({})).toBeNull();
+    expect(yHistoryAvailability({ undoStack: 5, redoStack: 5 })).toBeNull();
+    // Only one stack present (partial rename) is still not trusted.
+    expect(yHistoryAvailability({ undoStack: [] })).toBeNull();
+  });
+
+  it("pin-test: a real yjs UndoManager still exposes undoStack/redoStack arrays", () => {
+    const doc = new Y.Doc();
+    const text = doc.getText("prosemirror");
+    const undoManager = new Y.UndoManager(text);
+
+    // Fresh manager: both stacks empty -> nothing to undo/redo.
+    expect(yHistoryAvailability(undoManager)).toEqual({
+      canUndo: false,
+      canRedo: false,
+    });
+
+    // A tracked edit must push onto the private undoStack. If a future yjs
+    // renames these fields, yHistoryAvailability(undoManager) returns null and
+    // the expectation below fails loudly.
+    text.insert(0, "hello");
+    undoManager.stopCapturing();
+    expect(yHistoryAvailability(undoManager)).toEqual({
+      canUndo: true,
+      canRedo: false,
+    });
+
+    // Undoing moves the item to the redoStack -> redo becomes available.
+    undoManager.undo();
+    expect(yHistoryAvailability(undoManager)).toEqual({
+      canUndo: false,
+      canRedo: true,
+    });
+  });
+});

apps/client/src/features/editor/components/fixed-toolbar/use-toolbar-state.ts

@@ -35,6 +35,30 @@ export interface ToolbarState {
 // When neither history backend is installed (the pre-sync static editor —
 // mainExtensions only, undoRedo disabled), both fall through to 0 -> false,
 // matching the previous `safeCan` behavior.
+// Reads the Yjs UndoManager's undo/redo availability from its stack lengths.
+//
+// `undoStack` / `redoStack` are PRIVATE y-undo / yjs internals, so we touch them
+// defensively: a yjs or y-undo upgrade that renames or restructures these fields
+// must not silently mis-drive the toolbar buttons (nor throw on `.length` of
+// `undefined`). We only trust them when they are actually arrays; otherwise this
+// returns null and the caller falls back to a safe default. The pin-test in
+// use-toolbar-state.test.ts asserts the current library shape, so an upgrade that
+// breaks this contract fails loudly there instead of failing silently in the UI.
+export function yHistoryAvailability(
+  undoManager: unknown,
+): { canUndo: boolean; canRedo: boolean } | null {
+  if (!undoManager || typeof undoManager !== "object") return null;
+  const { undoStack, redoStack } = undoManager as {
+    undoStack?: unknown;
+    redoStack?: unknown;
+  };
+  if (!Array.isArray(undoStack) || !Array.isArray(redoStack)) return null;
+  return {
+    canUndo: undoStack.length > 0,
+    canRedo: redoStack.length > 0,
+  };
+}
+
 function historyAvailability(editor: Editor): {
   canUndo: boolean;
   canRedo: boolean;
@@ -43,16 +67,14 @@ function historyAvailability(editor: Editor): {
 
   // Collaboration history (Yjs) takes precedence when present.
   const yState = yUndoPluginKey.getState(state) as
-    | { undoManager?: { undoStack: unknown[]; redoStack: unknown[] } }
+    | { undoManager?: unknown }
     | undefined;
-  if (yState?.undoManager) {
-    return {
-      canUndo: yState.undoManager.undoStack.length > 0,
-      canRedo: yState.undoManager.redoStack.length > 0,
-    };
-  }
+  const yAvail = yHistoryAvailability(yState?.undoManager);
+  if (yAvail) return yAvail;
 
   // Plain prosemirror-history (returns 0 when the history plugin is absent).
+  // This is also the safe default when a Yjs UndoManager is present but its
+  // private stack shape is no longer recognized (yHistoryAvailability -> null).
   return {
     canUndo: undoDepth(state) > 0,
     canRedo: redoDepth(state) > 0,

apps/client/src/features/editor/extensions/markdown-clipboard.paste.test.ts

@@ -0,0 +1,206 @@
+import { describe, it, expect } from "vitest";
+import { Editor } from "@tiptap/core";
+import { Document } from "@tiptap/extension-document";
+import { Paragraph } from "@tiptap/extension-paragraph";
+import { Text } from "@tiptap/extension-text";
+import { Bold } from "@tiptap/extension-bold";
+import { Italic } from "@tiptap/extension-italic";
+import { MarkdownClipboard } from "./markdown-clipboard";
+
+/**
+ * Integration coverage for the async `handlePaste` seam (issue #347). The paste
+ * conversion moved to `@docmost/prosemirror-markdown`'s browser entry, whose
+ * `markdownToProseMirror` is async — so `handlePaste` captures the range, claims
+ * the event (returns true), and dispatches the insert on the next microtask.
+ * These tests drive that path end to end on a minimal schema (a plain-markdown
+ * paste whose converted nodes fit paragraph/text/bold/italic), asserting the
+ * text lands with the right marks and that the raw markdown syntax is consumed
+ * (recognized as markdown, not inserted literally).
+ */
+
+function makeEditor() {
+  const element = document.createElement("div");
+  document.body.appendChild(element);
+  return new Editor({
+    element,
+    extensions: [
+      Document,
+      Paragraph,
+      Text,
+      Bold,
+      Italic,
+      MarkdownClipboard.configure({ transformPastedText: true }),
+    ],
+    content: { type: "doc", content: [{ type: "paragraph" }] },
+  });
+}
+
+// Locate the markdownClipboard plugin and invoke its handlePaste directly with a
+// synthetic clipboard event (jsdom has no real paste pipeline). The plugin's
+// handlePaste closes over the extension `this`, so calling it off the plugin
+// props preserves `this.editor`/`this.options`.
+function paste(editor: Editor, text: string): boolean {
+  const view = editor.view;
+  const plugin = view.state.plugins.find(
+    (p: any) => p.props && p.spec?.key,
+  ) as any;
+  const event = {
+    clipboardData: {
+      getData: (type: string) => (type === "text/plain" ? text : ""),
+    },
+  } as unknown as ClipboardEvent;
+  // Find the specific handlePaste that belongs to the markdown clipboard plugin.
+  const md = view.state.plugins.find(
+    (p: any) => typeof p.props?.handlePaste === "function",
+  ) as any;
+  return md.props.handlePaste(view, event, view.state.selection.content());
+}
+
+// Flush the microtask queue so the async .then() dispatch runs.
+const flush = () => new Promise((r) => setTimeout(r, 0));
+
+describe("MarkdownClipboard handlePaste (async md -> PM)", () => {
+  it("converts a plain-markdown paste with bold/italic into marked text", async () => {
+    const editor = makeEditor();
+    const claimed = paste(editor, "hello **bold** and *italic*");
+    // The paste is claimed synchronously (async insert follows).
+    expect(claimed).toBe(true);
+    await flush();
+
+    const json = editor.getJSON();
+    const text = JSON.stringify(json);
+    // The raw markdown asterisks are consumed (recognized), not inserted literally.
+    expect(editor.getText()).not.toContain("**");
+    expect(editor.getText()).toContain("bold");
+    expect(editor.getText()).toContain("italic");
+    // The bold/italic marks materialized.
+    expect(text).toContain('"bold"');
+    expect(text).toContain('"italic"');
+    editor.destroy();
+  });
+
+  it("recognizes a bullet list paste as list structure (not literal '-')", async () => {
+    // A bullet list is not representable in this minimal schema, so the converter
+    // output would fail PMNode.fromJSON and the catch inserts raw text. Use a
+    // paste whose nodes DO fit the schema to assert the happy path instead: two
+    // paragraphs separated by a blank line.
+    const editor = makeEditor();
+    paste(editor, "first para\n\nsecond para");
+    await flush();
+    const json = editor.getJSON() as any;
+    const paras = (json.content || []).filter(
+      (n: any) => n.type === "paragraph",
+    );
+    // Two paragraphs materialized from the blank-line-separated markdown.
+    expect(paras.length).toBeGreaterThanOrEqual(2);
+    expect(editor.getText()).toContain("first para");
+    expect(editor.getText()).toContain("second para");
+    editor.destroy();
+  });
+
+  it("falls back to raw text when conversion yields nodes the schema lacks", async () => {
+    // `# heading` converts to a `heading` node absent from this minimal schema,
+    // so PMNode.fromJSON throws and the catch re-inserts the raw text — the user
+    // never loses their clipboard content.
+    const editor = makeEditor();
+    paste(editor, "# a heading line");
+    await flush();
+    // Content is preserved (either as heading text or literal), never dropped.
+    expect(editor.getText()).toContain("a heading line");
+    editor.destroy();
+  });
+});
+
+// The async seam captures the target range synchronously, then replaces on the
+// next microtask. If the document changed under it between capture and resolve
+// (impossible in prod — same microtask — but pinned here), BOTH the success
+// (replaceRange) and the fail-open (insertText) branches must fall back to the
+// LIVE selection rather than a stale absolute range, so neither clobbers content
+// nor throws a RangeError. We force the mid-flight change by dispatching a
+// doc-mutating transaction AFTER the synchronous claim but BEFORE flushing the
+// microtask that runs the `.then`/`.catch`.
+describe("MarkdownClipboard handlePaste — doc-changed-mid-flight guard", () => {
+  // Replace the whole doc with one paragraph of `text` (synchronous dispatch).
+  // An empty string yields an empty paragraph (a text node may not be empty).
+  function seedContent(editor: Editor, text: string) {
+    editor.commands.setContent({
+      type: "doc",
+      content: [
+        text
+          ? { type: "paragraph", content: [{ type: "text", text }] }
+          : { type: "paragraph" },
+      ],
+    });
+  }
+
+  it("success branch: mid-flight doc change routes the paste to the LIVE selection, never the stale range (clobber-proving)", async () => {
+    // The paste captures a NON-EMPTY range {1,5} (over "AAAA"). Then, before the
+    // async resolve, the doc GROWS ("MARKER" inserted at the start) and the cursor
+    // is parked at the doc END. The captured {1,5} is now stale and points INTO
+    // "MARKER". A WORKING guard replaces at the live (end) selection → MARKER is
+    // untouched. A BROKEN guard replaces the stale {1,5} → it erases the first
+    // characters of MARKER (this is what a zero-width `from==to` range could never
+    // reveal, which is why the earlier version was vacuous).
+    const editor = makeEditor();
+    seedContent(editor, "AAAABBBB");
+    editor.commands.setTextSelection({ from: 1, to: 5 }); // captured range = {1,5}
+    const claimed = paste(editor, "hello **bold**");
+    expect(claimed).toBe(true);
+
+    // Mid-flight: grow the doc and move the cursor to a KNOWN-safe end position.
+    editor.view.dispatch(editor.view.state.tr.insertText("MARKER", 1));
+    const end = editor.state.doc.content.size;
+    editor.commands.setTextSelection({ from: end, to: end });
+    await flush();
+
+    const text = editor.getText();
+    // MARKER intact only if the guard used the live selection, not the stale range.
+    expect(text).toContain("MARKER");
+    expect(text).toContain("bold");
+    expect(text).not.toContain("**");
+    editor.destroy();
+  });
+
+  it("fail-open branch: a mid-flight doc SHRINK makes the stale `to` out of bounds — the guard must avoid a RangeError (throw-proving)", async () => {
+    // The paste captures a range {1,9} over an 8-char paragraph, then the
+    // conversion FAILS (`# heading` -> a heading node the minimal schema lacks,
+    // so PMNode.fromJSON throws -> the fail-open catch runs). Before the reject,
+    // the doc is SHRUNK to an empty paragraph, so the captured `to` (9) is now far
+    // past the doc's end. A WORKING guard inserts the raw text at the live (valid)
+    // selection → "raw heading" lands. A BROKEN guard does insertText(md, 1, 9) on
+    // a size-2 doc → RangeError, so the dispatch never runs and "raw heading" is
+    // absent (the assertion reddens). A zero-width/growing-doc setup could never
+    // push `to` out of bounds, which is why the earlier version was vacuous.
+    const editor = makeEditor();
+    seedContent(editor, "AAAABBBB");
+    editor.commands.setTextSelection({ from: 1, to: 9 }); // captured range = {1,9}
+    paste(editor, "# raw heading");
+
+    // Mid-flight: shrink the doc so the captured `to` = 9 is now out of bounds.
+    seedContent(editor, "");
+    await flush();
+
+    const text = editor.getText();
+    // Raw text lands (via the live selection) only if the guard avoided the
+    // stale, now-out-of-bounds range.
+    expect(text).toContain("raw heading");
+    editor.destroy();
+  });
+
+  it("two pastes in flight: neither payload is lost (no data loss)", async () => {
+    // Prod-unreachable (two paste events are separate macrotasks, and each
+    // conversion resolves on a microtask before the next), but pinned here: when
+    // both resolve back-to-back, the second sees the changed doc and inserts at
+    // the live selection the first left — so the two payloads may INTERLEAVE, but
+    // neither is dropped. We assert no data loss, not contiguity.
+    const editor = makeEditor();
+    paste(editor, "alphaword");
+    paste(editor, "betaword");
+    await flush();
+    const text = editor.getText();
+    // Neither payload fully dropped (interleaving may split one of them).
+    expect(text).toContain("alpha");
+    expect(text).toContain("beta");
+    editor.destroy();
+  });
+});

apps/client/src/features/editor/extensions/markdown-clipboard.test.ts

@@ -1,5 +1,12 @@
 import { describe, it, expect } from "vitest";
-import { htmlToMarkdown } from "@docmost/editor-ext";
+// Markdown conversion now goes through the canonical package's BROWSER entry
+// (issue #347): the same converter the server import/export uses, resolved via
+// the `browser` exports condition so it runs on the native `DOMParser` (the
+// client jsdom vitest env provides one) with jsdom never bundled.
+import {
+  convertProseMirrorToMarkdown,
+  markdownToProseMirrorSync,
+} from "@docmost/prosemirror-markdown/browser";
 import {
   normalizeTableColumnWidths,
   classifyClipboardSelection,
@@ -175,10 +182,13 @@ describe("classifyClipboardSelection", () => {
 
 // Output-level tests for the table clipboard regression: copying a table must
 // yield a real GFM pipe table, NOT one-value-per-line concatenated cells.
-// These exercise the actual markdown produced by htmlToMarkdown (the same
-// serializer step the clipboardTextSerializer runs), so they pin the OUTPUT
-// shape that the classifier-flag tests above do not cover.
-describe("table clipboard markdown output (htmlToMarkdown)", () => {
+// These exercise the actual markdown produced by convertProseMirrorToMarkdown —
+// the same serializer step the clipboardTextSerializer now runs (issue #347) —
+// so they pin the OUTPUT shape that the classifier-flag tests above do not cover.
+// Input is ProseMirror JSON (what the copied slice serializes to), matching the
+// clipboardTextSerializer's new call: it wraps the slice content in a synthetic
+// `doc` (and the bare-rows case in a `table`) and calls the converter.
+describe("table clipboard markdown output (convertProseMirrorToMarkdown)", () => {
   // Trim each line and drop blanks so structural assertions are whitespace-robust.
   function lines(md: string): string[] {
     return md
@@ -188,10 +198,10 @@ describe("table clipboard markdown output (htmlToMarkdown)", () => {
   }
 
   // A GFM separator row like "| --- | --- |" (any number of columns), tolerant
-  // of the padding turndown emits.
+  // of the padding the serializer emits.
   function isSeparatorRow(line: string): boolean {
     const compact = line.replace(/\s+/g, "");
-    return /^\|(?:-{3,}\|)+$/.test(compact);
+    return /^\|(?::?-{2,}:?\|)+$/.test(compact);
   }
 
   // Split a pipe-delimited row into trimmed cell values.
@@ -203,42 +213,33 @@ describe("table clipboard markdown output (htmlToMarkdown)", () => {
       .map((c) => c.trim());
   }
 
-  it("serializes a header-less partial cell selection (bare rows) as a valid GFM pipe table", () => {
-    // Mirror the serializer's `wrapBareRows` branch exactly: bare <tr> nodes are
-    // wrapped in <table><tbody> and htmlToMarkdown(div.innerHTML) is called.
-    // See markdown-clipboard.ts clipboardTextSerializer:
-    //   const table = document.createElement("table");
-    //   const tbody = document.createElement("tbody");
-    //   tbody.appendChild(fragment); table.appendChild(tbody);
-    //   div.appendChild(table);
-    //   return htmlToMarkdown(div.innerHTML);
-    const div = document.createElement("div");
-    const table = document.createElement("table");
-    const tbody = document.createElement("tbody");
-    for (const [c1, c2] of [
-      ["a", "b"],
-      ["c", "d"],
-    ]) {
-      const tr = document.createElement("tr");
-      const td1 = document.createElement("td");
-      td1.textContent = c1;
-      const td2 = document.createElement("td");
-      td2.textContent = c2;
-      tr.appendChild(td1);
-      tr.appendChild(td2);
-      tbody.appendChild(tr);
-    }
-    table.appendChild(tbody);
-    div.appendChild(table);
+  const cell = (t: string) => ({
+    type: "tableCell",
+    content: [{ type: "paragraph", content: [{ type: "text", text: t }] }],
+  });
+  const headerCell = (t: string) => ({
+    type: "tableHeader",
+    content: [{ type: "paragraph", content: [{ type: "text", text: t }] }],
+  });
+  const row = (nodes: any[]) => ({ type: "tableRow", content: nodes });
 
-    const md = htmlToMarkdown(div.innerHTML);
+  it("serializes a header-less partial cell selection (bare rows) as a valid GFM pipe table", () => {
+    // Mirror the serializer's `wrapBareRows` branch: bare tableRow nodes are
+    // wrapped in a synthetic `table` and convertProseMirrorToMarkdown is called
+    // (see markdown-clipboard.ts clipboardTextSerializer).
+    const rows = [
+      row([cell("a"), cell("b")]),
+      row([cell("c"), cell("d")]),
+    ];
+    const md = convertProseMirrorToMarkdown({
+      type: "doc",
+      content: [{ type: "table", content: rows }],
+    });
     const ls = lines(md);
 
-    // Valid GFM: a header/data separator row is present (an empty header is
-    // synthesized by the GFM turndown plugin for a header-less table — fine).
+    // Valid GFM: a header/data separator row is present.
     expect(ls.some(isSeparatorRow)).toBe(true);
-    // NOT the old broken "one value per line" shape: every line is pipe-delimited
-    // and no line is a bare cell value on its own.
+    // NOT the old broken "one value per line" shape: every line is pipe-delimited.
     expect(ls.every((l) => l.includes("|"))).toBe(true);
     expect(md).not.toMatch(/^\s*(a|b|c|d)\s*$/m);
     // The cell values land in real pipe-delimited data rows.
@@ -248,39 +249,21 @@ describe("table clipboard markdown output (htmlToMarkdown)", () => {
   });
 
   it("serializes a whole table with a header row as a proper GFM table (headline regression)", () => {
-    // Mirror the serializer's non-wrap branch: the full <table> node is appended
-    // directly (div.appendChild(fragment)) and htmlToMarkdown(div.innerHTML) runs.
-    const div = document.createElement("div");
-    const table = document.createElement("table");
-
-    const thead = document.createElement("thead");
-    const headerRow = document.createElement("tr");
-    for (const h of ["Name", "Age"]) {
-      const th = document.createElement("th");
-      th.textContent = h;
-      headerRow.appendChild(th);
-    }
-    thead.appendChild(headerRow);
-    table.appendChild(thead);
-
-    const tbody = document.createElement("tbody");
-    for (const [name, age] of [
-      ["Alice", "30"],
-      ["Bob", "25"],
-    ]) {
-      const tr = document.createElement("tr");
-      const td1 = document.createElement("td");
-      td1.textContent = name;
-      const td2 = document.createElement("td");
-      td2.textContent = age;
-      tr.appendChild(td1);
-      tr.appendChild(td2);
-      tbody.appendChild(tr);
-    }
-    table.appendChild(tbody);
-    div.appendChild(table);
-
-    const md = htmlToMarkdown(div.innerHTML);
+    // Mirror the serializer's non-wrap branch: the full `table` node is the
+    // slice content and convertProseMirrorToMarkdown runs on it.
+    const md = convertProseMirrorToMarkdown({
+      type: "doc",
+      content: [
+        {
+          type: "table",
+          content: [
+            row([headerCell("Name"), headerCell("Age")]),
+            row([cell("Alice"), cell("30")]),
+            row([cell("Bob"), cell("25")]),
+          ],
+        },
+      ],
+    });
     const ls = lines(md);
 
     // Proper GFM structure: separator row + all rows pipe-delimited.
@@ -296,3 +279,146 @@ describe("table clipboard markdown output (htmlToMarkdown)", () => {
     expect(md).not.toMatch(/^\s*(Name|Age|Alice|Bob|30|25)\s*$/m);
   });
 });
+
+// #347 acceptance: pasting CANONICAL markdown yields the SAME nodes the server
+// import produces for the same text. The paste path calls markdownToProseMirror
+// (the package browser entry) — the identical converter the server import uses —
+// so asserting the converter (via the browser entry, on the native DOMParser)
+// recognizes each canon form pins the paste-parity guarantee. These forms were
+// NOT recognized by the old editor-ext marked layer the paste used before.
+describe("canonical markdown paste recognition (browser entry parity)", () => {
+  // Collect every node type present in a doc (recursively).
+  const collectTypes = (n: any, set = new Set<string>()): Set<string> => {
+    if (!n || typeof n !== "object") return set;
+    if (n.type) set.add(n.type);
+    if (Array.isArray(n.content)) n.content.forEach((c) => collectTypes(c, set));
+    return set;
+  };
+  const findNode = (n: any, type: string): any => {
+    if (!n || typeof n !== "object") return undefined;
+    if (n.type === type) return n;
+    if (Array.isArray(n.content)) {
+      for (const c of n.content) {
+        const hit = findNode(c, type);
+        if (hit) return hit;
+      }
+    }
+    return undefined;
+  };
+  const allText = (n: any): string => {
+    if (!n || typeof n !== "object") return "";
+    if (typeof n.text === "string") return n.text;
+    if (Array.isArray(n.content)) return n.content.map(allText).join("");
+    return "";
+  };
+
+  it("^[…] inline footnote -> footnoteReference + footnotesList", () => {
+    const doc = markdownToProseMirrorSync("Body^[a note here].");
+    const types = collectTypes(doc);
+    expect(types.has("footnoteReference")).toBe(true);
+    expect(types.has("footnotesList")).toBe(true);
+    expect(types.has("footnoteDefinition")).toBe(true);
+  });
+
+  it('<!--img {…}--> attached image comment -> image with align', () => {
+    const doc = markdownToProseMirrorSync(
+      '![alt](/files/x.png) <!--img {"align":"left"}-->',
+    );
+    const img = findNode(doc, "image");
+    expect(img).toBeTruthy();
+    expect(img.attrs?.align).toBe("left");
+    expect(img.attrs?.src).toBe("/files/x.png");
+  });
+
+  it("> [!type] Obsidian callout -> callout node with type", () => {
+    const doc = markdownToProseMirrorSync("> [!warning]\n> be careful");
+    const callout = findNode(doc, "callout");
+    expect(callout).toBeTruthy();
+    expect(callout.attrs?.type).toBe("warning");
+    expect(allText(callout)).toContain("be careful");
+  });
+
+  it("$…$ inline math -> mathInline node", () => {
+    const doc = markdownToProseMirrorSync("Euler: $e^{i\\pi}+1=0$ done");
+    const math = findNode(doc, "mathInline");
+    expect(math).toBeTruthy();
+    expect(math.attrs?.text).toContain("e^{i\\pi}");
+  });
+
+  it("==…== highlight -> highlight mark", () => {
+    const doc = markdownToProseMirrorSync("A ==marked== word");
+    const marked = findNode(doc, "text");
+    // The highlighted run carries a `highlight` mark somewhere in the doc.
+    const hasHighlight = (n: any): boolean => {
+      if (!n || typeof n !== "object") return false;
+      if (
+        n.type === "text" &&
+        (n.marks || []).some((m: any) => m.type === "highlight")
+      )
+        return true;
+      return Array.isArray(n.content) ? n.content.some(hasHighlight) : false;
+    };
+    expect(marked).toBeTruthy();
+    expect(hasHighlight(doc)).toBe(true);
+  });
+
+  it("<!--subpages--> standalone comment -> subpages node", () => {
+    const doc = markdownToProseMirrorSync("intro\n\n<!--subpages-->\n\nafter");
+    expect(collectTypes(doc).has("subpages")).toBe(true);
+  });
+});
+
+// #347 negatives: plain text carrying markdown-LIKE punctuation must NOT be
+// silently converted/mangled (currency, bare `==`, a `[^1]` reference form).
+describe("plain-text paste negatives (no phantom conversion)", () => {
+  const findNode = (n: any, type: string): any => {
+    if (!n || typeof n !== "object") return undefined;
+    if (n.type === type) return n;
+    if (Array.isArray(n.content)) {
+      for (const c of n.content) {
+        const hit = findNode(c, type);
+        if (hit) return hit;
+      }
+    }
+    return undefined;
+  };
+  const collectTypes = (n: any, set = new Set<string>()): Set<string> => {
+    if (!n || typeof n !== "object") return set;
+    if (n.type) set.add(n.type);
+    if (Array.isArray(n.content)) n.content.forEach((c) => collectTypes(c, set));
+    return set;
+  };
+  const allText = (n: any): string => {
+    if (!n || typeof n !== "object") return "";
+    if (typeof n.text === "string") return n.text;
+    if (Array.isArray(n.content)) return n.content.map(allText).join("");
+    return "";
+  };
+
+  it("currency `$5 and $10` is NOT turned into math", () => {
+    const doc = markdownToProseMirrorSync("It costs $5 and $10 total");
+    expect(findNode(doc, "mathInline")).toBeFalsy();
+    expect(allText(doc)).toContain("$5 and $10");
+  });
+
+  it("a lone `==` is NOT turned into a highlight", () => {
+    const doc = markdownToProseMirrorSync("compare a == b in code");
+    const hasHighlight = (n: any): boolean => {
+      if (!n || typeof n !== "object") return false;
+      if (
+        n.type === "text" &&
+        (n.marks || []).some((m: any) => m.type === "highlight")
+      )
+        return true;
+      return Array.isArray(n.content) ? n.content.some(hasHighlight) : false;
+    };
+    expect(hasHighlight(doc)).toBe(false);
+    expect(allText(doc)).toContain("== b");
+  });
+
+  it("a `[^1]` reference form (no `^[`) is NOT turned into a footnote", () => {
+    const doc = markdownToProseMirrorSync("see note [^1] for details");
+    expect(collectTypes(doc).has("footnoteReference")).toBe(false);
+    expect(allText(doc)).toContain("[^1]");
+  });
+});

apps/client/src/features/editor/extensions/markdown-clipboard.ts

@@ -1,15 +1,23 @@
 // adapted from: https://github.com/aguingand/tiptap-markdown/blob/main/src/extensions/tiptap/clipboard.js - MIT
 import { Extension } from "@tiptap/core";
 import { Plugin, PluginKey, TextSelection } from "@tiptap/pm/state";
-import { DOMParser, DOMSerializer, Fragment, Slice } from "@tiptap/pm/model";
+import { DOMParser, DOMSerializer, Fragment, Slice, Node as PMNode } from "@tiptap/pm/model";
 import { find } from "linkifyjs";
 import {
-  markdownToHtml,
-  htmlToMarkdown,
   canonicalizeFootnotes,
   FOOTNOTES_LIST_NAME,
   FOOTNOTE_REFERENCE_NAME,
 } from "@docmost/editor-ext";
+// Markdown <-> ProseMirror conversion now lives ONLY in the canonical
+// `@docmost/prosemirror-markdown` package (issue #347). The BROWSER entry uses
+// the native `DOMParser` for its HTML->DOM stage (jsdom stays out of the client
+// bundle) while producing the SAME nodes the server import does — so a paste of
+// canonical markdown (`^[…]`, `<!--img …-->`, `> [!type]`, `$…$`, `==…==`,
+// standalone comments) is recognized identically to import.
+import {
+  markdownToProseMirror,
+  convertProseMirrorToMarkdown,
+} from "@docmost/prosemirror-markdown/browser";
 import type { Schema } from "@tiptap/pm/model";
 
 export const MarkdownClipboard = Extension.create({
@@ -39,25 +47,24 @@ export const MarkdownClipboard = Extension.create({
               classifyClipboardSelection(topLevelNodes);
             if (!asMarkdown) return null;
 
-            const div = document.createElement("div");
-            const serializer = DOMSerializer.fromSchema(this.editor.schema);
-            const fragment = serializer.serializeFragment(slice.content);
-
+            // Convert the copied selection to Markdown through the canonical
+            // package (issue #347), the SAME serializer the server export uses,
+            // so a copied table/list matches the on-disk markdown form. The
+            // converter takes a ProseMirror `doc` JSON, so wrap the slice's
+            // top-level content in a synthetic doc.
+            const content = slice.content.toJSON() as any[];
             if (wrapBareRows) {
-              // A partial table cell-selection serializes to bare <tr> nodes
-              // (prosemirror-tables returns the whole `table` node only when the
-              // entire table is selected). Bare <tr> would be foster-parented
-              // away by the HTML parser inside htmlToMarkdown, so wrap them in
-              // <table><tbody> first for the GFM turndown rule to detect them.
-              const table = document.createElement("table");
-              const tbody = document.createElement("tbody");
-              tbody.appendChild(fragment);
-              table.appendChild(tbody);
-              div.appendChild(table);
-            } else {
-              div.appendChild(fragment);
+              // A partial table cell-selection serializes to bare `tableRow`
+              // nodes (prosemirror-tables yields the whole `table` node only for
+              // a full-table selection). The converter's table case expects a
+              // `table` wrapper, so wrap the bare rows in one — mirroring the old
+              // <table><tbody> wrap that the HTML->markdown step needed.
+              return convertProseMirrorToMarkdown({
+                type: "doc",
+                content: [{ type: "table", content }],
+              });
             }
-            return htmlToMarkdown(div.innerHTML);
+            return convertProseMirrorToMarkdown({ type: "doc", content });
           },
           handlePaste: (view, event, slice) => {
             if (!event.clipboardData) {
@@ -95,37 +102,115 @@ export const MarkdownClipboard = Extension.create({
               }
             }
 
-            const { tr } = view.state;
-            const { from, to } = view.state.selection;
+            const schema = this.editor.schema;
+            // Capture the target range NOW. markdownToProseMirror RETURNS A
+            // PROMISE (kept async only for the Node consumers' contract; the
+            // conversion pipeline itself is synchronous), so the actual replace
+            // happens on the next microtask. No user input can interleave a
+            // microtask, so the state is unchanged when we dispatch — but we
+            // still re-read the live state before replacing and, if the doc did
+            // change under us, fall back to the live selection rather than the
+            // captured (now-stale) range.
+            const from = view.state.selection.from;
+            const to = view.state.selection.to;
+            const startDoc = view.state.doc;
+            const md = text.replace(/\n+$/, "");
 
-            const parsed = markdownToHtml(text.replace(/\n+$/, ""));
-            const body = elementFromString(parsed);
-            normalizeTableColumnWidths(body);
+            void markdownToProseMirror(md)
+              .then((doc) => {
+                if (view.isDestroyed) return;
+                // Canonical PM-JSON -> HTML via the LIVE editor schema, then
+                // reuse the UNCHANGED downstream seam (normalizeTableColumnWidths
+                // + parseSlice + canonicalizePastedFootnotes). The JSON->HTML->
+                // JSON hop is lossless (same schema both directions); it lets the
+                // existing paste-insertion logic stay byte-identical — only the
+                // SOURCE of the markdown conversion changed (issue #347 guardrail:
+                // no converter logic in the client, only a call into the package).
+                const node = PMNode.fromJSON(schema, doc);
+                const div = document.createElement("div");
+                DOMSerializer.fromSchema(schema).serializeFragment(
+                  node.content,
+                  { document },
+                  div,
+                );
 
-            const parsedSlice = DOMParser.fromSchema(
-              this.editor.schema,
-            ).parseSlice(body, {
-              preserveWhitespace: true,
-            });
+                const body = elementFromString(div.innerHTML);
+                normalizeTableColumnWidths(body);
 
-            // A markdown paste builds its ProseMirror fragment directly (DOM ->
-            // parseSlice), bypassing the editor's footnoteSyncPlugin, which never
-            // reorders an existing list. So a pasted markdown block whose footnote
-            // definitions are out of order (or contains orphan defs) would be
-            // stored out of order. Canonicalize the self-contained pasted block so
-            // its footnotes come out reference-ordered, deduped and orphan-free
-            // (issue #228). See canonicalizePastedFootnotes for why this is scoped
-            // to whole-block pastes that carry their own footnotesList.
-            const contentNodes = canonicalizePastedFootnotes(
-              parsedSlice,
-              this.editor.schema,
-            );
+                const parsedSlice = DOMParser.fromSchema(schema).parseSlice(
+                  body,
+                  { preserveWhitespace: true },
+                );
 
-            tr.replaceRange(from, to, contentNodes);
-            const insertEnd = tr.mapping.map(from, 1);
-            tr.setSelection(TextSelection.near(tr.doc.resolve(Math.max(from, insertEnd - 2)), -1));
-            tr.setMeta('paste', true)
-            view.dispatch(tr);
+                // A markdown paste builds its ProseMirror fragment directly (DOM
+                // -> parseSlice), bypassing the editor's footnoteSyncPlugin, which
+                // never reorders an existing list. So a pasted markdown block whose
+                // footnote definitions are out of order (or contains orphan defs)
+                // would be stored out of order. Canonicalize the self-contained
+                // pasted block so its footnotes come out reference-ordered, deduped
+                // and orphan-free (issue #228). See canonicalizePastedFootnotes for
+                // why this is scoped to whole-block pastes that carry their own
+                // footnotesList.
+                const contentNodes = canonicalizePastedFootnotes(
+                  parsedSlice,
+                  schema,
+                );
+
+                // Target the captured range (normally still valid — same
+                // microtask). If the doc changed under us since capture, the
+                // captured absolute from/to are stale, so fall back to the live
+                // selection rather than StepMap-mapping the old range.
+                const tr = view.state.tr;
+                let mappedFrom = from;
+                let mappedTo = to;
+                if (view.state.doc !== startDoc) {
+                  // Defensive: if the doc changed under us, fall back to the
+                  // current selection rather than a stale absolute range.
+                  mappedFrom = view.state.selection.from;
+                  mappedTo = view.state.selection.to;
+                }
+                tr.replaceRange(mappedFrom, mappedTo, contentNodes);
+                const insertEnd = tr.mapping.map(mappedFrom, 1);
+                tr.setSelection(
+                  TextSelection.near(
+                    tr.doc.resolve(Math.max(mappedFrom, insertEnd - 2)),
+                    -1,
+                  ),
+                );
+                tr.setMeta("paste", true);
+                view.dispatch(tr);
+              })
+              .catch((err) => {
+                // Fail-open: a conversion error must not swallow the paste
+                // silently in a way that loses the text. We already claimed the
+                // event (returned true), so re-insert the raw text as a plain
+                // paragraph so the user never loses their clipboard content.
+                // Log it: this catch covers BOTH the converter and the success
+                // `.then` body (e.g. PMNode.fromJSON throwing on a schema drift
+                // between the canonical package and the live editor schema), so a
+                // silent degrade to raw text would otherwise be an invisible,
+                // non-reproducible regression ("my table pasted as text").
+                console.error(
+                  "markdown paste conversion failed, inserting raw text",
+                  err,
+                );
+                if (view.isDestroyed) return;
+                const tr = view.state.tr;
+                // Same guard the success path uses: if the doc changed under us
+                // since the range was captured (normally never — same microtask),
+                // the captured absolute from/to are stale and would throw a
+                // RangeError here (an unhandled rejection on a hot paste path).
+                // Fall back to the live selection instead of a stale range.
+                if (view.state.doc !== startDoc) {
+                  const sel = view.state.selection;
+                  tr.insertText(md, sel.from, sel.to);
+                } else {
+                  tr.insertText(md, from, to);
+                }
+                tr.setMeta("paste", true);
+                view.dispatch(tr);
+              });
+            // Claim the paste: we insert asynchronously above.
             return true;
           },
           // Strip trailing whitespace-only paragraphs from pasted content.

apps/client/src/features/editor/gitmost/gitmost-recording.test.ts

@@ -9,7 +9,7 @@ import { Italic } from "@tiptap/extension-italic";
 import { Link } from "@tiptap/extension-link";
 import { gitmostInsertTranscriptIntoEditor } from "./gitmost-recording.ts";
 
-const ZWSP = "​"; // U+200B, the helper's block-trigger neutralizer
+const ZWSP = "​"; // U+200B — asserted ABSENT (the block-escape lives in the serializer now)
 
 /**
  * #377 — the web-side bridge must append the native host's transcript below the
@@ -18,8 +18,9 @@ const ZWSP = "​"; // U+200B, the helper's block-trigger neutralizer
  * regression would be caught), asserting the resulting document rather than
  * mocking the editor: transcript present -> "Transcript" heading + one paragraph
  * per non-empty line; content is inserted as LITERAL TEXT (no HTML/markdown
- * parsing); col-0 markdown block triggers are neutralized so git-sync keeps them
- * paragraphs; absent/empty/non-string -> no-op.
+ * parsing); col-0 markdown block triggers are stored verbatim (the git-sync
+ * serializer block-escapes them, so no client-side ZWSP is needed);
+ * absent/empty/non-string -> no-op.
  */
 describe("gitmostInsertTranscriptIntoEditor", () => {
   const makeEditor = () =>
@@ -91,19 +92,22 @@ describe("gitmostInsertTranscriptIntoEditor", () => {
     editor.destroy();
   });
 
-  it("neutralizes col-0 markdown block triggers with a leading ZWSP (git-sync safety)", () => {
+  it("inserts col-0 markdown block triggers as verbatim paragraph text (no ZWSP workaround)", () => {
     const editor = makeEditor();
-    // Trigger lines (some with a leaked indent) + a normal prefixed line.
+    // Trigger lines (some with a leaked indent) + a normal prefixed line. The
+    // git-sync serializer now block-escapes a leading trigger itself, so the
+    // bridge inserts each line's TEXT byte-exact (only the leaked indent is
+    // trimmed) — no invisible ZWSP is prepended anymore.
     const inserted = gitmostInsertTranscriptIntoEditor(
       editor,
       [
         "- dash",
-        "  > quote", // leading indent must be trimmed then neutralized
+        "  > quote", // leading indent is trimmed, text otherwise verbatim
         "# hash",
         "1. one",
         "> [!info] note",
         "```js",
-        "---", // solid thematic break -> horizontalRule (text-losing) if unneutralized
+        "---",
         "***",
         "___",
         "You: normal line",
@@ -116,20 +120,23 @@ describe("gitmostInsertTranscriptIntoEditor", () => {
       .map((n: any) => n.content?.[0]?.text)
       .filter((t: any) => typeof t === "string") as string[];
 
-    // Every block-trigger line is prefixed with the invisible ZWSP (indent
-    // trimmed first); the normal `You:` line is left byte-exact.
+    // Each trigger line is stored as its own byte-exact text (indent trimmed);
+    // the git-sync round-trip keeps it a paragraph via the serializer's
+    // block-escape, so no ZWSP is needed here.
     expect(texts).toEqual([
-      ZWSP + "- dash",
-      ZWSP + "> quote",
-      ZWSP + "# hash",
-      ZWSP + "1. one",
-      ZWSP + "> [!info] note",
-      ZWSP + "```js",
-      ZWSP + "---",
-      ZWSP + "***",
-      ZWSP + "___",
+      "- dash",
+      "> quote",
+      "# hash",
+      "1. one",
+      "> [!info] note",
+      "```js",
+      "---",
+      "***",
+      "___",
       "You: normal line",
     ]);
+    // Guard: no invisible ZWSP leaked into any inserted line.
+    for (const t of texts) expect(t).not.toContain(ZWSP);
 
     editor.destroy();
   });

apps/client/src/features/editor/gitmost/gitmost-recording.ts

@@ -240,45 +240,22 @@ export async function gitmostUploadFileToEditor(
   }
 }
 
-// Zero-width space (U+200B). Prepended to a transcript line that begins with a
-// markdown BLOCK trigger: it is invisible in the rendered doc but shifts the
-// trigger off column 0, so the git-sync doc->markdown->doc round-trip keeps the
-// line a plain paragraph (see GITMOST_MD_BLOCK_TRIGGER_RE).
-const GITMOST_ZWSP = "​";
-
-// A markdown BLOCK-level construct that, sitting at column 0 of a paragraph
-// line, the git-sync markdown serializer (packages/prosemirror-markdown
-// markdown-converter.ts, `case "paragraph"`) would re-parse into a NON-paragraph
-// block on the doc->markdown->doc cycle. That serializer emits paragraph text
-// verbatim with NO block-escape (the pre-existing root cause), so a leading
-// `#`/`-`/`*`/`+`/`>`, an ordered-list `N.`/`N)`, a code fence ```/~~~, a table
-// `|`, or a `> [!info]` callout opener would silently become a heading / list /
-// quote / code block / table / callout. The final alternative matches a WHOLE-
-// LINE thematic break — solid `---`/`***`/`___` or spaced `- - -`/`_ _ _` (3+ of
-// the same `-`/`*`/`_`) — which round-trips into a `horizontalRule`; because
-// that node carries NO text, an un-neutralized separator line would LOSE its
-// text entirely (worse than the list/quote case). This matches a TRIMMED line's
-// start; the transcript's own `You:` / `Speaker N:` prefix begins with a letter
-// and never matches, so prefixed lines are left byte-exact.
-const GITMOST_MD_BLOCK_TRIGGER_RE =
-  /^(?:#{1,6}(?:\s|$)|[-*+](?:\s|$)|>|\d+[.)](?:\s|$)|```|~~~|\||([-*_])(?:\s*\1){2,}\s*$)/;
-
 // Append a transcript block BELOW the recording's audio node in a live editor:
 // a "Transcript" heading followed by one paragraph per non-empty transcript
 // line. The transcript is plain text, `\n`-separated, each line already
 // formatted as `You: ...` / `Speaker N: ...` by the native host — line text is
 // inserted as a TEXT node (never HTML/markdown), so there is no injection or
 // mark-parsing surface. Each kept line is trimmed (drops an indent that would
-// both leak into the display and, at col 0, form a markdown block trigger) and,
-// if it still begins with a col-0 markdown block trigger, gets an invisible
-// zero-width space prepended so the git-sync round-trip cannot turn it into a
-// list/quote/heading/callout/code/table (defensive boundary against the
-// serializer's missing block-escape). This is best-effort and meant to run
-// AFTER the audio has already been inserted; the caller must guard against a
-// throw so a transcript failure never fails the (already successful) recording.
-// Returns true when a block was inserted, false when there was nothing to
-// insert (transcript undefined/empty/not-a-string). A non-string value is a
-// no-op, not an error.
+// leak into the display). A line that begins with a col-0 markdown block
+// trigger (`#`/`-`/`>`/`1.`/fence/`---`/…) needs no client-side workaround: the
+// git-sync serializer (packages/prosemirror-markdown, `case "paragraph"`) now
+// block-escapes such a leading trigger, so the doc->markdown->doc round-trip
+// keeps the line a paragraph on its own — the former invisible-ZWSP defense is
+// gone. This is best-effort and meant to run AFTER the audio has already been
+// inserted; the caller must guard against a throw so a transcript failure never
+// fails the (already successful) recording. Returns true when a block was
+// inserted, false when there was nothing to insert (transcript
+// undefined/empty/not-a-string). A non-string value is a no-op, not an error.
 export function gitmostInsertTranscriptIntoEditor(
   editor: Editor,
   transcript: unknown,
@@ -288,13 +265,7 @@ export function gitmostInsertTranscriptIntoEditor(
     .split("\n")
     // Trim each line and drop blank (whitespace-only) ones.
     .map((line) => line.trim())
-    .filter((line) => line.length > 0)
-    // Neutralize a col-0 markdown block trigger with an invisible ZWSP so the
-    // git-sync round-trip keeps the line a paragraph. Host lines (`You:` /
-    // `Speaker N:`) never match and stay byte-exact.
-    .map((line) =>
-      GITMOST_MD_BLOCK_TRIGGER_RE.test(line) ? GITMOST_ZWSP + line : line,
-    );
+    .filter((line) => line.length > 0);
   if (lines.length === 0) return false;
 
   const content = [

apps/client/src/features/editor/hooks/use-generate-page-title.test.tsx

@@ -33,10 +33,11 @@ vi.mock("@/lib/local-emitter.ts", () => ({
   default: { emit: (...args: unknown[]) => localEmitMock(...args) },
 }));
 
-// htmlToMarkdown just echoes the editor HTML so each test controls the markdown
-// purely via the fake page editor's getHTML().
-vi.mock("@docmost/editor-ext", () => ({
-  htmlToMarkdown: (html: string) => html,
+// convertProseMirrorToMarkdown echoes a marker carried on the fake editor's
+// getJSON() doc, so each test controls the markdown purely via the fake page
+// editor (issue #347: the hook now serializes editor JSON through the package).
+vi.mock("@docmost/prosemirror-markdown/browser", () => ({
+  convertProseMirrorToMarkdown: (doc: { __md?: string }) => doc?.__md ?? "",
 }));
 
 const notificationsShowMock = vi.fn();
@@ -53,10 +54,12 @@ import { useGeneratePageTitle } from "./use-generate-page-title.ts";
 
 // --- Test helpers -------------------------------------------------------------
 
-function makePageEditor(pageId: string, html = "<p>content</p>"): Editor {
+function makePageEditor(pageId: string, md = "content"): Editor {
   return {
     isDestroyed: false,
-    getHTML: () => html,
+    // The mocked convertProseMirrorToMarkdown reads `__md` back off this doc,
+    // so `md` is exactly the markdown the hook will send to the title service.
+    getJSON: () => ({ type: "doc", __md: md }),
     storage: { pageId },
   } as unknown as Editor;
 }

apps/client/src/features/editor/hooks/use-generate-page-title.ts

@@ -3,7 +3,7 @@ import { useMutation } from "@tanstack/react-query";
 import { useAtomValue } from "jotai";
 import { notifications } from "@mantine/notifications";
 import { useTranslation } from "react-i18next";
-import { htmlToMarkdown } from "@docmost/editor-ext";
+import { convertProseMirrorToMarkdown } from "@docmost/prosemirror-markdown/browser";
 import {
   pageEditorAtom,
   titleEditorAtom,
@@ -49,7 +49,9 @@ export function useGeneratePageTitle(pageId: string) {
     mutationFn: async () => {
       if (!pageEditor || pageEditor.isDestroyed) return;
 
-      const markdown = htmlToMarkdown(pageEditor.getHTML()).trim();
+      // Serialize the live editor content to markdown through the canonical
+      // converter (issue #347), matching the on-disk/export markdown form.
+      const markdown = convertProseMirrorToMarkdown(pageEditor.getJSON()).trim();
       if (!markdown) {
         notifications.show({ message: t("The note is empty"), color: "yellow" });
         return;

apps/client/src/features/editor/page-editor.tsx

@@ -31,11 +31,18 @@ import { useAtom, useAtomValue, useSetAtom } from "jotai";
 import useCollaborationUrl from "@/features/editor/hooks/use-collaboration-url";
 import { currentUserAtom } from "@/features/user/atoms/current-user-atom";
 import {
+  collabProviderAtom,
   currentPageEditModeAtom,
   dictationAvailabilityAtom,
   pageEditorAtom,
   yjsConnectionStatusAtom,
 } from "@/features/editor/atoms/editor-atoms";
+import { notifications } from "@mantine/notifications";
+import {
+  VERSION_SAVED_MESSAGE_TYPE,
+  type VersionSavedMessage,
+  saveVersionPending,
+} from "@/features/page-history/version-messages";
 import { asideStateAtom } from "@/components/layouts/global/hooks/atoms/sidebar-atom";
 import {
   activeCommentIdAtom,
@@ -124,6 +131,7 @@ export default function PageEditor({
 
   const [currentUser] = useAtom(currentUserAtom);
   const [, setEditor] = useAtom(pageEditorAtom);
+  const setCollabProvider = useSetAtom(collabProviderAtom);
   const [, setAsideState] = useAtom(asideStateAtom);
   const [, setActiveCommentId] = useAtom(activeCommentIdAtom);
   const [showCommentPopup, setShowCommentPopup] = useAtom(showCommentPopupAtom);
@@ -181,6 +189,24 @@ export default function PageEditor({
       const onStatelessHandler = ({ payload }: onStatelessParameters) => {
         try {
           const message = JSON.parse(payload);
+          // #370 — a version was saved somewhere; live-refresh the history panel
+          // on every client. Only the client that pressed Save (tracked by the
+          // module-level flag) shows the confirmation toast.
+          if (message?.type === VERSION_SAVED_MESSAGE_TYPE) {
+            const versionMsg = message as VersionSavedMessage;
+            queryClient.invalidateQueries({
+              queryKey: ["page-history-list"],
+            });
+            if (saveVersionPending.current) {
+              saveVersionPending.current = false;
+              notifications.show({
+                message: versionMsg.alreadySaved
+                  ? t("Already saved as the latest version")
+                  : t("Version saved"),
+              });
+            }
+            return;
+          }
           if (message?.type !== "page.updated" || !message.updatedAt) return;
           const pageData = queryClient.getQueryData<IPage>(["pages", slugId]);
           if (pageData) {
@@ -238,12 +264,16 @@ export default function PageEditor({
 
       local.on("synced", onLocalSyncedHandler);
       providersRef.current = { socket, local, remote };
+      // #370 — publish the provider so the header menu can emit save-version.
+      setCollabProvider(remote);
       setProvidersReady(true);
     } else {
+      setCollabProvider(providersRef.current.remote);
       setProvidersReady(true);
     }
     // Only destroy on final unmount
     return () => {
+      setCollabProvider(null);
       providersRef.current?.socket.destroy();
       providersRef.current?.remote.destroy();
       providersRef.current?.local.destroy();

apps/client/src/features/page-history/components/history-item.tsx

@@ -1,4 +1,11 @@
-import { Text, Group, UnstyledButton, Avatar, Tooltip } from "@mantine/core";
+import {
+  Text,
+  Group,
+  UnstyledButton,
+  Avatar,
+  Tooltip,
+  Badge,
+} from "@mantine/core";
 import { CustomAvatar } from "@/components/ui/custom-avatar.tsx";
 import { AgentAvatarStack } from "@/components/ui/agent-avatar-stack.tsx";
 import { formattedDate } from "@/lib/time";
@@ -7,36 +14,59 @@ import clsx from "clsx";
 import { IPageHistory } from "@/features/page-history/types/page.types";
 import { memo, useCallback } from "react";
 import { useSetAtom } from "jotai";
+import { useTranslation } from "react-i18next";
 import { historyAtoms } from "@/features/page-history/atoms/history-atoms.ts";
 
 const MAX_VISIBLE_AVATARS = 5;
 
+/**
+ * #370 — map a snapshot's intentionality tier to its badge. `version: true`
+ * marks the intentional points (manual / agent); autosaves (boundary / idle /
+ * legacy null) are non-versions and get dimmed in the list.
+ */
+type HistoryKindMeta = { labelKey: string; color: string; version: boolean };
+export function historyKindMeta(kind?: string | null): HistoryKindMeta {
+  switch (kind) {
+    case "manual":
+      return { labelKey: "Saved", color: "blue", version: true };
+    case "agent":
+      return { labelKey: "Agent version", color: "violet", version: true };
+    case "boundary":
+      return { labelKey: "Boundary", color: "gray", version: false };
+    default: // "idle" | null | undefined (legacy autosave)
+      return { labelKey: "Autosave", color: "gray", version: false };
+  }
+}
+
 interface HistoryItemProps {
   historyItem: IPageHistory;
-  index: number;
-  onSelect: (id: string, index: number) => void;
-  onHover?: (id: string, index: number) => void;
+  // The previous snapshot for diff/restore is resolved by id from the FULL list
+  // in the parent (resolvePrevSnapshotId), so the item only needs to report its
+  // own id — never a list index (which would be the filtered-view index).
+  onSelect: (id: string) => void;
+  onHover?: (id: string) => void;
   onHoverEnd?: () => void;
   isActive: boolean;
 }
 
 const HistoryItem = memo(function HistoryItem({
   historyItem,
-  index,
   onSelect,
   onHover,
   onHoverEnd,
   isActive,
 }: HistoryItemProps) {
   const setHistoryModalOpen = useSetAtom(historyAtoms);
+  const { t } = useTranslation();
+  const kindMeta = historyKindMeta(historyItem.kind);
 
   const handleClick = useCallback(() => {
-    onSelect(historyItem.id, index);
-  }, [onSelect, historyItem.id, index]);
+    onSelect(historyItem.id);
+  }, [onSelect, historyItem.id]);
 
   const handleMouseEnter = useCallback(() => {
-    onHover?.(historyItem.id, index);
-  }, [onHover, historyItem.id, index]);
+    onHover?.(historyItem.id);
+  }, [onHover, historyItem.id]);
 
   const contributors = historyItem.contributors;
   const hasContributors = contributors && contributors.length > 0;
@@ -49,8 +79,20 @@ const HistoryItem = memo(function HistoryItem({
       onMouseEnter={handleMouseEnter}
       onMouseLeave={onHoverEnd}
       className={clsx(classes.history, { [classes.active]: isActive })}
+      // #370 — dim autosnapshots so intentional versions stand out.
+      style={{ opacity: kindMeta.version ? 1 : 0.55 }}
     >
-      <Text size="sm">{formattedDate(new Date(historyItem.createdAt))}</Text>
+      <Group gap={6} wrap="nowrap" justify="space-between">
+        <Text size="sm">{formattedDate(new Date(historyItem.createdAt))}</Text>
+        <Badge
+          size="xs"
+          radius="sm"
+          variant={kindMeta.version ? "filled" : "light"}
+          color={kindMeta.color}
+        >
+          {t(kindMeta.labelKey)}
+        </Badge>
+      </Group>
 
       <Group gap={6} wrap="nowrap" mt={4}>
         {hasContributors ? (

apps/client/src/features/page-history/components/history-list.tsx

@@ -2,14 +2,16 @@ import {
   usePageHistoryListQuery,
   prefetchPageHistory,
 } from "@/features/page-history/queries/page-history-query";
-import HistoryItem from "@/features/page-history/components/history-item";
+import HistoryItem, {
+  historyKindMeta,
+} from "@/features/page-history/components/history-item";
 import {
   activeHistoryIdAtom,
   activeHistoryPrevIdAtom,
   historyAtoms,
 } from "@/features/page-history/atoms/history-atoms";
 import { useAtom, useSetAtom } from "jotai";
-import { useCallback, useEffect, useMemo, useRef } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import {
   Button,
   ScrollArea,
@@ -17,9 +19,12 @@ import {
   Divider,
   Loader,
   Center,
+  Switch,
+  Text,
 } from "@mantine/core";
 import { useTranslation } from "react-i18next";
 import { useHistoryRestore } from "@/features/page-history/hooks";
+import { resolvePrevSnapshotId } from "@/features/page-history/utils/resolve-prev-snapshot";
 
 const PREFETCH_DELAY_MS = 150;
 
@@ -47,6 +52,22 @@ function HistoryList({ pageId }: Props) {
     [pageHistoryData],
   );
 
+  // #370 — "only versions" filter: hide autosnapshots (idle/boundary/legacy
+  // null), keep only intentional points (manual/agent). Filtering is over the
+  // already-loaded pages; the diff/restore still targets the true previous
+  // snapshot, so items carry their index within the FULL list.
+  const [onlyVersions, setOnlyVersions] = useState(false);
+  // Reuse historyKindMeta().version — the SAME predicate the badge (HistoryItem)
+  // uses to mark intentional points — so the "Only versions" filter and the badge
+  // can never drift apart when a future intentional kind is added.
+  const visibleItems = useMemo(
+    () =>
+      onlyVersions
+        ? historyItems.filter((item) => historyKindMeta(item.kind).version)
+        : historyItems,
+    [historyItems, onlyVersions],
+  );
+
   const loadMoreRef = useRef<HTMLDivElement>(null);
   const prefetchTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 
@@ -60,11 +81,13 @@ function HistoryList({ pageId }: Props) {
   }, []);
 
   const handleHover = useCallback(
-    (historyId: string, index: number) => {
+    (historyId: string) => {
       clearPrefetchTimeout();
       prefetchTimeoutRef.current = setTimeout(() => {
         prefetchPageHistory(historyId);
-        const prevId = historyItems[index + 1]?.id;
+        // The true previous snapshot in the FULL list (not the previous visible
+        // one under the "only versions" filter).
+        const prevId = resolvePrevSnapshotId(historyItems, historyId);
         if (prevId) {
           prefetchPageHistory(prevId);
         }
@@ -78,9 +101,11 @@ function HistoryList({ pageId }: Props) {
   }, [clearPrefetchTimeout]);
 
   const handleSelect = useCallback(
-    (id: string, index: number) => {
+    (id: string) => {
       setActiveHistoryId(id);
-      setActiveHistoryPrevId(historyItems[index + 1]?.id ?? "");
+      // Baseline = true previous snapshot in the FULL list, so the "only
+      // versions" filter never diffs/restores against the wrong item.
+      setActiveHistoryPrevId(resolvePrevSnapshotId(historyItems, id));
     },
     [historyItems, setActiveHistoryId, setActiveHistoryPrevId],
   );
@@ -128,12 +153,27 @@ function HistoryList({ pageId }: Props) {
 
   return (
     <div>
+      <Group px="xs" py={6} justify="flex-end">
+        <Switch
+          size="xs"
+          checked={onlyVersions}
+          onChange={(e) => setOnlyVersions(e.currentTarget.checked)}
+          label={t("Only versions")}
+        />
+      </Group>
+
       <ScrollArea h={620} w="100%" type="scroll" scrollbarSize={5}>
-        {historyItems.map((historyItem, index) => (
+        {onlyVersions && visibleItems.length === 0 && (
+          <Center py="md">
+            <Text size="sm" c="dimmed">
+              {t("No saved versions yet.")}
+            </Text>
+          </Center>
+        )}
+        {visibleItems.map((historyItem) => (
           <HistoryItem
             key={historyItem.id}
             historyItem={historyItem}
-            index={index}
             onSelect={handleSelect}
             onHover={handleHover}
             onHoverEnd={clearPrefetchTimeout}

apps/client/src/features/page-history/types/page.types.ts

@@ -24,6 +24,10 @@ export interface IPageHistory {
   updatedAt: string;
   lastUpdatedBy: IPageHistoryUser;
   contributors?: IPageHistoryUser[];
+  // #370 — intentionality tier: 'manual'/'agent' are versions (intentional
+  // points), 'idle'/'boundary' are autosnapshots; null/undefined = legacy
+  // autosave. Derived server-side, drives the history badge + "versions" filter.
+  kind?: "manual" | "agent" | "idle" | "boundary" | null;
   // Provenance markers copied off the page row when the snapshot was saved.
   // `'agent'` marks a version written by the AI agent; `lastUpdatedAiChatId`
   // (when present) deep-links to the chat that produced the edit.

apps/client/src/features/page-history/utils/resolve-prev-snapshot.test.ts

@@ -0,0 +1,42 @@
+import { describe, it, expect } from "vitest";
+import { resolvePrevSnapshotId } from "./resolve-prev-snapshot";
+
+// #370 F4 — the risky client path: with the "only versions" filter active, diff
+// and restore must still baseline against the TRUE previous snapshot in the FULL
+// list, never the previous VISIBLE version (which would skip the autosnapshots
+// between two versions). These pin that the resolution is by FULL-list order.
+describe("resolvePrevSnapshotId", () => {
+  // Newest-first, as the history list stores it: a version, then two autosaves,
+  // then an older version.
+  const full = [
+    { id: "v2", kind: "manual" },
+    { id: "a2", kind: "idle" },
+    { id: "a1", kind: "boundary" },
+    { id: "v1", kind: "manual" },
+    { id: "a0", kind: null },
+  ];
+
+  it("returns the immediate FULL-list successor, not the previous visible version", () => {
+    // Selecting v2 while filtered to versions-only must baseline against a2 (the
+    // real chronological predecessor), NOT v1 (the previous visible version).
+    expect(resolvePrevSnapshotId(full, "v2")).toBe("a2");
+  });
+
+  it("resolves an autosnapshot's predecessor by full-list order", () => {
+    expect(resolvePrevSnapshotId(full, "a1")).toBe("v1");
+  });
+
+  it("returns '' for the oldest item (no predecessor)", () => {
+    expect(resolvePrevSnapshotId(full, "a0")).toBe("");
+  });
+
+  it("returns '' for an id not in the list", () => {
+    expect(resolvePrevSnapshotId(full, "missing")).toBe("");
+  });
+
+  it("does not depend on a filtered subset — same result whatever is visible", () => {
+    // The helper only ever sees the full list; a filtered view cannot change the
+    // baseline it computes.
+    expect(resolvePrevSnapshotId(full, "v1")).toBe("a0");
+  });
+});

apps/client/src/features/page-history/utils/resolve-prev-snapshot.ts

@@ -0,0 +1,22 @@
+/**
+ * #370 — resolve the TRUE previous snapshot for a history item.
+ *
+ * The history panel can be filtered to "only versions" (manual/agent), but diff
+ * and restore must always compare against the immediately-preceding snapshot in
+ * the FULL, unfiltered list — NOT the previous VISIBLE item. Comparing against
+ * the previous visible version would silently skip the autosnapshots between two
+ * versions and diff/restore the wrong baseline.
+ *
+ * Given the full (newest-first) list and an item id, this returns the id of the
+ * item right after it in the full list (its chronological predecessor), or "" if
+ * it is the oldest / not found. Pure and list-order-preserving so it can be unit
+ * tested without mounting the component.
+ */
+export function resolvePrevSnapshotId(
+  fullItems: ReadonlyArray<{ id: string }>,
+  id: string,
+): string {
+  const index = fullItems.findIndex((item) => item.id === id);
+  if (index === -1) return "";
+  return fullItems[index + 1]?.id ?? "";
+}

apps/client/src/features/page-history/version-messages.ts

@@ -0,0 +1,28 @@
+/**
+ * #370 — page-version stateless wire formats. Kept in one place so the client
+ * emitter (Save hotkey / button) and the client listener (page-editor) agree
+ * with the server (PersistenceExtension) on the message shapes.
+ */
+
+/** Client → server: "save a version now". The server derives the tier
+ * (manual/agent) from the signed connection actor, never from this payload. */
+export const SAVE_VERSION_MESSAGE_TYPE = "save-version";
+
+/** Server → all clients: a version was saved (or promoted / already existed). */
+export const VERSION_SAVED_MESSAGE_TYPE = "version.saved";
+
+export interface VersionSavedMessage {
+  type: typeof VERSION_SAVED_MESSAGE_TYPE;
+  historyId: string;
+  kind: "manual" | "agent";
+  /** True when the latest snapshot was already a manual version (a no-op save). */
+  alreadySaved: boolean;
+}
+
+/**
+ * Cross-component coordination flag so only the client that pressed Save shows
+ * the confirmation toast, while every other client silently refreshes its
+ * history panel on the broadcast. A module-level ref avoids stale-closure
+ * pitfalls in the editor's long-lived stateless handler.
+ */
+export const saveVersionPending = { current: false };

apps/client/src/features/page-history/work-time/format-work-time.test.ts

@@ -0,0 +1,45 @@
+import { describe, it, expect } from "vitest";
+import {
+  formatHeadline,
+  formatDayTotal,
+  formatGapMinutes,
+} from "./format-work-time";
+
+const MIN = 60 * 1000;
+// Fake translator: renders the key with {{tokens}} substituted, so the tests
+// assert the rounding + branch selection without depending on the i18n catalogue.
+const t = (key: string, opts?: Record<string, unknown>) =>
+  key.replace(/\{\{(\w+)\}\}/g, (_, k) => String(opts?.[k] ?? ""));
+
+describe("formatHeadline", () => {
+  it("prefixes ≈ and rounds to a 5-minute step", () => {
+    expect(formatHeadline(4 * 60 * MIN + 27 * MIN, t)).toBe("≈ 4h 25m");
+    expect(formatHeadline(90 * MIN, t)).toBe("≈ 1h 30m");
+  });
+
+  it("shows hours only / minutes only cleanly", () => {
+    expect(formatHeadline(120 * MIN, t)).toBe("≈ 2h");
+    expect(formatHeadline(35 * MIN, t)).toBe("≈ 35m");
+  });
+
+  it("floors a tiny non-zero estimate to 5m, never 0", () => {
+    expect(formatHeadline(2 * MIN, t)).toBe("≈ 5m");
+  });
+
+  it("empty string for zero (widget hidden)", () => {
+    expect(formatHeadline(0, t)).toBe("");
+  });
+});
+
+describe("formatDayTotal", () => {
+  it('renders "h m" and shows — for empty days', () => {
+    expect(formatDayTotal(3 * 60 * MIN + 17 * MIN, t)).toBe("3h 17m");
+    expect(formatDayTotal(0, t)).toBe("—");
+  });
+});
+
+describe("formatGapMinutes", () => {
+  it("converts the tGap ms threshold to whole minutes", () => {
+    expect(formatGapMinutes(15 * MIN)).toBe(15);
+  });
+});

apps/client/src/features/page-history/work-time/format-work-time.ts

@@ -0,0 +1,45 @@
+// #395 — display formatting for the work-time estimate. Pure functions that take
+// a translator so ru-RU / en-US wording lives in the i18n catalogue and the
+// rounding logic stays unit-testable.
+
+type Translate = (key: string, opts?: Record<string, unknown>) => string;
+
+const MIN = 60 * 1000;
+
+function hm(totalMinutes: number): { hours: number; minutes: number } {
+  return {
+    hours: Math.floor(totalMinutes / 60),
+    minutes: totalMinutes % 60,
+  };
+}
+
+/**
+ * Headline number (§6.1): an ESTIMATE, so rounded to a coarse 5-minute step and
+ * prefixed with "≈". A non-zero-but-tiny estimate floors to 5m rather than
+ * rounding down to "0" (which would read as "no work"). Zero → empty string
+ * (the caller hides the widget).
+ */
+export function formatHeadline(workMs: number, t: Translate): string {
+  if (workMs <= 0) return "";
+  let minutes = Math.round(workMs / MIN / 5) * 5;
+  if (minutes === 0) minutes = 5;
+  const { hours, minutes: m } = hm(minutes);
+  if (hours > 0 && m > 0) return t("≈ {{hours}}h {{minutes}}m", { hours, minutes: m });
+  if (hours > 0) return t("≈ {{hours}}h", { hours });
+  return t("≈ {{minutes}}m", { minutes: m });
+}
+
+/** Per-day sum (§6.2), rounded to the minute. Zero → "—". */
+export function formatDayTotal(activeMs: number, t: Translate): string {
+  if (activeMs <= 0) return "—";
+  const minutes = Math.max(1, Math.round(activeMs / MIN));
+  const { hours, minutes: m } = hm(minutes);
+  if (hours > 0 && m > 0) return t("{{hours}}h {{minutes}}m", { hours, minutes: m });
+  if (hours > 0) return t("{{hours}}h", { hours });
+  return t("{{minutes}}m", { minutes: m });
+}
+
+/** The inactivity threshold, for the "estimate · gap = N min" caption. */
+export function formatGapMinutes(tGapMs: number): number {
+  return Math.round(tGapMs / MIN);
+}

apps/client/src/features/page-history/work-time/use-page-work-time.ts

@@ -0,0 +1,25 @@
+import { useQuery, UseQueryResult } from "@tanstack/react-query";
+import { IPageWorkTime } from "./work-time.types";
+import { getPageWorkTime, viewerTimezone } from "./work-time-service";
+
+const WORK_TIME_STALE_TIME = 5 * 60 * 1000;
+
+/**
+ * #395 — the "time worked on this article" estimate + per-day punch-card
+ * buckets. The buckets are computed server-side in the viewer's timezone (so a
+ * midnight-crossing session lands on the right calendar day for the reader).
+ * `enabled` is opt-in so the (cheap but non-trivial) projection query only fires
+ * when the number is actually shown.
+ */
+export function usePageWorkTime(
+  pageId: string,
+  enabled = true,
+): UseQueryResult<IPageWorkTime, Error> {
+  const tz = viewerTimezone();
+  return useQuery({
+    queryKey: ["page-work-time", pageId, tz],
+    queryFn: () => getPageWorkTime(pageId, tz),
+    enabled: enabled && !!pageId,
+    staleTime: WORK_TIME_STALE_TIME,
+  });
+}

apps/client/src/features/page-history/work-time/work-time-punch-card.tsx

@@ -0,0 +1,171 @@
+import { Group, Stack, Text } from "@mantine/core";
+import { useTranslation } from "react-i18next";
+import { useMemo } from "react";
+import { IPageWorkTime, IPerDay, IDayWindow } from "./work-time.types";
+import {
+  formatDayTotal,
+  formatGapMinutes,
+  formatHeadline,
+} from "./format-work-time";
+import classes from "./work-time.module.css";
+
+const DAY_MS = 24 * 60 * 60 * 1000;
+// Collapse a run of this many (or more) consecutive edit-free days into a single
+// "× N days" separator (§6.2 long-range) — the row is still always one day.
+const EMPTY_RUN_COLLAPSE = 8;
+
+type Row =
+  | { type: "day"; day: IPerDay }
+  | { type: "gap"; count: number };
+
+function collapseEmptyRuns(perDay: IPerDay[]): Row[] {
+  const rows: Row[] = [];
+  let emptyRun: IPerDay[] = [];
+  const flush = () => {
+    if (emptyRun.length >= EMPTY_RUN_COLLAPSE) {
+      rows.push({ type: "gap", count: emptyRun.length });
+    } else {
+      for (const d of emptyRun) rows.push({ type: "day", day: d });
+    }
+    emptyRun = [];
+  };
+  for (const d of perDay) {
+    if (d.activeMs === 0 && d.agentMs === 0) {
+      emptyRun.push(d);
+    } else {
+      flush();
+      rows.push({ type: "day", day: d });
+    }
+  }
+  flush();
+  return rows;
+}
+
+function dayHeading(day: number): string {
+  return new Date(day).toLocaleDateString(undefined, {
+    weekday: "short",
+    day: "numeric",
+    month: "short",
+  });
+}
+
+function DayTrack({
+  day,
+  pSingle,
+}: {
+  day: IPerDay;
+  pSingle: number;
+}) {
+  const { t } = useTranslation();
+  const ticks = [6, 12, 18];
+  return (
+    <div className={classes.row}>
+      <span className={classes.dayLabel}>{dayHeading(day.day)}</span>
+      <div className={classes.track}>
+        {ticks.map((h) => (
+          <div
+            key={h}
+            className={classes.hourTick}
+            style={{ left: `${(h / 24) * 100}%` }}
+          />
+        ))}
+        {day.windows.map((w: IDayWindow, i) => {
+          const leftPct = ((w.start - day.day) / DAY_MS) * 100;
+          const widthPct = ((w.end - w.start) / DAY_MS) * 100;
+          const isSingle = w.end - w.start <= pSingle;
+          const cls = [
+            classes.window,
+            w.class === "work" ? classes.windowWork : classes.windowAgent,
+            isSingle ? classes.windowSingle : "",
+          ].join(" ");
+          return (
+            <div
+              key={i}
+              className={cls}
+              style={{
+                left: `${Math.max(0, Math.min(100, leftPct))}%`,
+                width: `${Math.max(0, Math.min(100, widthPct))}%`,
+              }}
+            />
+          );
+        })}
+      </div>
+      <span className={classes.daySum}>
+        {formatDayTotal(day.activeMs, t)}
+      </span>
+    </div>
+  );
+}
+
+interface Props {
+  data: IPageWorkTime;
+}
+
+export default function WorkTimePunchCard({ data }: Props) {
+  const { t } = useTranslation();
+  const rows = useMemo(() => collapseEmptyRuns(data.perDay), [data.perDay]);
+  const gapMin = formatGapMinutes(data.config.tGap);
+
+  if (data.workMs <= 0 && data.agentOnlyMs <= 0) {
+    return (
+      <Text size="sm" c="dimmed" py="md">
+        {t("No editing activity recorded yet.")}
+      </Text>
+    );
+  }
+
+  return (
+    <Stack gap="xs">
+      <Group gap="lg">
+        <Text size="sm" fw={500}>
+          {formatHeadline(data.workMs, t)}
+        </Text>
+        {data.agentOnlyMs > 0 && (
+          <Text size="xs" c="dimmed">
+            {t("agent: {{value}}", { value: formatHeadline(data.agentOnlyMs, t) })}
+          </Text>
+        )}
+      </Group>
+
+      <Group gap="md">
+        <Text size="xs" c="dimmed">
+          <span
+            className={`${classes.legendSwatch} ${classes.windowWork}`}
+            style={{ marginRight: 4 }}
+          />
+          {t("Work")}
+        </Text>
+        <Text size="xs" c="dimmed">
+          <span
+            className={`${classes.legendSwatch} ${classes.windowAgent}`}
+            style={{ marginRight: 4 }}
+          />
+          {t("Agent")}
+        </Text>
+      </Group>
+
+      <div>
+        {rows.map((row, i) =>
+          row.type === "day" ? (
+            <DayTrack
+              key={row.day.dayISO}
+              day={row.day}
+              pSingle={data.config.pSingle}
+            />
+          ) : (
+            <div key={`gap-${i}`} className={classes.gapRow}>
+              {t("× {{count}} days without edits", { count: row.count })}
+            </div>
+          ),
+        )}
+      </div>
+
+      <Text size="xs" c="dimmed" mt="xs">
+        {t("Estimate · timezone {{tz}} · inactivity gap {{gap}} min", {
+          tz: data.tz,
+          gap: gapMin,
+        })}
+      </Text>
+    </Stack>
+  );
+}

apps/client/src/features/page-history/work-time/work-time-service.ts

@@ -0,0 +1,23 @@
+import api from "@/lib/api-client";
+import { IPageWorkTime } from "./work-time.types";
+
+/** The viewer's IANA timezone (browser locale) — the punch-card lays days out
+ *  in "my evenings", per §6.3/§10. Falls back to UTC if the runtime hides it. */
+export function viewerTimezone(): string {
+  try {
+    return Intl.DateTimeFormat().resolvedOptions().timeZone || "UTC";
+  } catch {
+    return "UTC";
+  }
+}
+
+export async function getPageWorkTime(
+  pageId: string,
+  tz: string,
+): Promise<IPageWorkTime> {
+  const req = await api.post<IPageWorkTime>("/pages/history/time", {
+    pageId,
+    tz,
+  });
+  return req.data;
+}

apps/client/src/features/page-history/work-time/work-time-stat.tsx

@@ -0,0 +1,69 @@
+import { Modal, Text, Tooltip, UnstyledButton } from "@mantine/core";
+import { useDisclosure } from "@mantine/hooks";
+import { IconClockHour4 } from "@tabler/icons-react";
+import { useTranslation } from "react-i18next";
+import { usePageWorkTime } from "./use-page-work-time";
+import { formatGapMinutes, formatHeadline } from "./format-work-time";
+import WorkTimePunchCard from "./work-time-punch-card";
+
+interface Props {
+  pageId: string;
+}
+
+/**
+ * #395 — the clickable "time worked on this article" headline (§6.1). Renders
+ * the `work` estimate with a "≈" sign and the inactivity threshold in a tooltip
+ * (it is an estimate, not a stopwatch). Clicking opens the daily punch-card
+ * (§6.2). Renders nothing until there is a non-zero human OR agent estimate, so a
+ * brand-new / never-edited page shows no widget. For an agent-only-edited page
+ * (workMs===0, agentOnlyMs>0) the headline shows the agent estimate (labelled
+ * `agent:`, matching the punch-card) so the punch-card stays reachable (#395:
+ * "how much a HUMAN and separately the AGENT").
+ */
+export default function WorkTimeStat({ pageId }: Props) {
+  const { t } = useTranslation();
+  const [opened, { open, close }] = useDisclosure(false);
+  const { data } = usePageWorkTime(pageId);
+
+  if (!data || (data.workMs <= 0 && data.agentOnlyMs <= 0)) return null;
+
+  const agentOnly = data.workMs <= 0;
+  const label = agentOnly
+    ? t("agent: {{value}}", { value: formatHeadline(data.agentOnlyMs, t) })
+    : formatHeadline(data.workMs, t);
+  const gapMin = formatGapMinutes(data.config.tGap);
+
+  return (
+    <>
+      <Tooltip
+        label={t("Estimated time worked (inactivity gap {{gap}} min)", {
+          gap: gapMin,
+        })}
+        position="bottom"
+      >
+        <UnstyledButton
+          onClick={open}
+          aria-label={t("Show time worked on this page")}
+        >
+          <Text
+            size="xs"
+            c="dimmed"
+            style={{ display: "inline-flex", alignItems: "center", gap: 4 }}
+          >
+            <IconClockHour4 size={14} />
+            {label}
+          </Text>
+        </UnstyledButton>
+      </Tooltip>
+
+      <Modal
+        opened={opened}
+        onClose={close}
+        title={t("Time worked on this article")}
+        size="lg"
+      >
+        <WorkTimePunchCard data={data} />
+      </Modal>
+    </>
+  );
+}

apps/client/src/features/page-history/work-time/work-time.module.css

@@ -0,0 +1,82 @@
+/* #395 — 24h × days punch-card. Custom CSS segments on a fixed 24-hour track
+   (position = offset-in-day / 24h, width = duration / 24h), no chart library. */
+
+.row {
+  display: grid;
+  grid-template-columns: 96px 1fr 64px;
+  align-items: center;
+  gap: 12px;
+  padding: 3px 0;
+}
+
+.dayLabel {
+  font-size: var(--mantine-font-size-xs);
+  color: var(--mantine-color-dimmed);
+  white-space: nowrap;
+}
+
+.track {
+  position: relative;
+  height: 16px;
+  border-radius: 4px;
+  background-color: light-dark(
+    var(--mantine-color-gray-1),
+    var(--mantine-color-dark-6)
+  );
+  overflow: hidden;
+}
+
+/* Faint hour grid so the eye can read "morning vs evening". */
+.hourTick {
+  position: absolute;
+  top: 0;
+  bottom: 0;
+  width: 1px;
+  background-color: light-dark(
+    var(--mantine-color-gray-3),
+    var(--mantine-color-dark-4)
+  );
+}
+
+.window {
+  position: absolute;
+  top: 2px;
+  bottom: 2px;
+  border-radius: 3px;
+  min-width: 3px;
+}
+
+.windowWork {
+  background-color: var(--mantine-color-blue-5);
+}
+
+.windowAgent {
+  background-color: var(--mantine-color-grape-5);
+}
+
+/* A lone single-sample (P_single) window: minimal + dimmed, so it neither
+   vanishes nor fakes dense work (§6.2). */
+.windowSingle {
+  opacity: 0.5;
+}
+
+.daySum {
+  font-size: var(--mantine-font-size-xs);
+  text-align: right;
+  white-space: nowrap;
+}
+
+.gapRow {
+  padding: 6px 0 6px 108px;
+  font-size: var(--mantine-font-size-xs);
+  color: var(--mantine-color-dimmed);
+  font-style: italic;
+}
+
+.legendSwatch {
+  display: inline-block;
+  width: 12px;
+  height: 12px;
+  border-radius: 3px;
+  vertical-align: middle;
+}

apps/client/src/features/page-history/work-time/work-time.types.ts

@@ -0,0 +1,37 @@
+// #395 — client-side mirror of the server work-time payload
+// (apps/server/src/core/page/work-time). Shapes returned by POST /pages/history/time.
+
+export type WorkSessionClass = "work" | "agent_only";
+
+export interface IDayWindow {
+  start: number;
+  end: number;
+  class: WorkSessionClass;
+}
+
+export interface IPerDay {
+  day: number;
+  dayISO: string;
+  activeMs: number;
+  agentMs: number;
+  windows: IDayWindow[];
+}
+
+export interface IWorkTimeConfig {
+  tGap: number;
+  agentTGap: number;
+  pIn: number;
+  pOut: number;
+  pSingle: number;
+  excludeGit: boolean;
+  burstCapMs?: number;
+  dedupRoundMs: number;
+}
+
+export interface IPageWorkTime {
+  workMs: number;
+  agentOnlyMs: number;
+  perDay: IPerDay[];
+  config: IWorkTimeConfig;
+  tz: string;
+}

apps/client/src/features/page/components/header/page-header-menu.tsx

@@ -3,6 +3,7 @@ import {
   IconArrowRight,
   IconArrowsHorizontal,
   IconClockHour4,
+  IconDeviceFloppy,
   IconDots,
   IconEye,
   IconEyeOff,
@@ -17,7 +18,7 @@ import {
   IconTrash,
   IconWifiOff,
 } from "@tabler/icons-react";
-import React, { useEffect, useRef, useState } from "react";
+import React, { useCallback, useEffect, useRef, useState } from "react";
 import { useAsideTriggerProps } from "@/hooks/use-toggle-aside.tsx";
 import { useAtom, useAtomValue } from "jotai";
 import { historyAtoms } from "@/features/page-history/atoms/history-atoms.ts";
@@ -37,14 +38,20 @@ import { useTreeMutation } from "@/features/page/tree/hooks/use-tree-mutation.ts
 import { PageWidthToggle } from "@/features/user/components/page-width-pref.tsx";
 import { Trans, useTranslation } from "react-i18next";
 import ExportModal from "@/components/common/export-modal";
-import { htmlToMarkdown } from "@docmost/editor-ext";
+import { convertProseMirrorToMarkdown } from "@docmost/prosemirror-markdown/browser";
 import {
+  collabProviderAtom,
   pageEditorAtom,
   yjsConnectionStatusAtom,
 } from "@/features/editor/atoms/editor-atoms.ts";
+import {
+  SAVE_VERSION_MESSAGE_TYPE,
+  saveVersionPending,
+} from "@/features/page-history/version-messages.ts";
 import { formattedDate } from "@/lib/time.ts";
 import { PageEditModeToggle } from "@/features/user/components/page-state-pref.tsx";
 import MovePageModal from "@/features/page/components/move-page-modal.tsx";
+import WorkTimeStat from "@/features/page-history/work-time/work-time-stat.tsx";
 import { useTimeAgo } from "@/hooks/use-time-ago.tsx";
 import {
   useFavoriteIds,
@@ -72,9 +79,34 @@ export default function PageHeaderMenu({ readOnly }: PageHeaderMenuProps) {
   });
   const isDeleted = !!page?.deletedAt;
   const [workspace] = useAtom(workspaceAtom);
+  const collabProvider = useAtomValue(collabProviderAtom);
   // Community public-sharing entry point (replaces the removed EE PageShareModal)
   const workspaceSharingDisabled = workspace?.settings?.sharing?.disabled === true;
 
+  // #370 — explicit "save a version" (Cmd+S / Save button). One path for the
+  // human; the server derives the tier from the signed actor. Readers can't save
+  // (the button is hidden and the collab connection is read-only server-side).
+  const handleSaveVersion = useCallback(() => {
+    if (readOnly || !collabProvider) return;
+    // Flag this client as the initiator so only it shows the confirmation toast;
+    // a safety timeout clears it if no broadcast comes back (e.g. offline).
+    saveVersionPending.current = true;
+    window.setTimeout(() => {
+      saveVersionPending.current = false;
+    }, 5000);
+    collabProvider.sendStateless(
+      JSON.stringify({ type: SAVE_VERSION_MESSAGE_TYPE }),
+    );
+  }, [readOnly, collabProvider]);
+
+  // mod+S must also block the browser's "Save page" dialog. `triggerOnContent-
+  // Editable` + empty ignore-list so it fires while typing in the editor/title.
+  useHotkeys(
+    [["mod+S", handleSaveVersion, { preventDefault: true }]],
+    [],
+    true,
+  );
+
   useHotkeys(
     [
       [
@@ -133,15 +165,16 @@ export default function PageHeaderMenu({ readOnly }: PageHeaderMenuProps) {
         </ActionIcon>
       </Tooltip>
 
-      <PageActionMenu readOnly={readOnly} />
+      <PageActionMenu readOnly={readOnly} onSaveVersion={handleSaveVersion} />
     </>
   );
 }
 
 interface PageActionMenuProps {
   readOnly?: boolean;
+  onSaveVersion?: () => void;
 }
-function PageActionMenu({ readOnly }: PageActionMenuProps) {
+function PageActionMenu({ readOnly, onSaveVersion }: PageActionMenuProps) {
   const { t } = useTranslation();
   const [, setHistoryModalOpen] = useAtom(historyAtoms);
   const clipboard = useClipboard({ timeout: 500 });
@@ -199,8 +232,9 @@ function PageActionMenu({ readOnly }: PageActionMenuProps) {
 
   const handleCopyAsMarkdown = () => {
     if (!pageEditor) return;
-    const html = pageEditor.getHTML();
-    const markdown = htmlToMarkdown(html);
+    // Copy the page as canonical markdown through the shared converter (issue
+    // #347), so "Copy as markdown" matches the server export byte-for-byte.
+    const markdown = convertProseMirrorToMarkdown(pageEditor.getJSON());
     const title = page?.title ? `# ${page.title}\n\n` : "";
     clipboard.copy(`${title}${markdown}`);
     notifications.show({ message: t("Copied") });
@@ -232,6 +266,8 @@ function PageActionMenu({ readOnly }: PageActionMenuProps) {
 
   return (
     <>
+      {page?.id && <WorkTimeStat pageId={page.id} />}
+
       <Menu
         shadow="xl"
         position="bottom-end"
@@ -302,6 +338,20 @@ function PageActionMenu({ readOnly }: PageActionMenuProps) {
             </Group>
           </Menu.Item>
 
+          {!readOnly && (
+            <Menu.Item
+              leftSection={<IconDeviceFloppy size={16} />}
+              onClick={onSaveVersion}
+              rightSection={
+                <Text size="xs" c="dimmed">
+                  {t("Ctrl+S")}
+                </Text>
+              }
+            >
+              {t("Save version")}
+            </Menu.Item>
+          )}
+
           <Menu.Item
             leftSection={<IconHistory size={16} />}
             onClick={openHistoryModal}

apps/client/src/features/page/tree/components/space-tree.tsx

@@ -281,10 +281,12 @@ const SpaceTree = forwardRef<SpaceTreeApi, SpaceTreeProps>(function SpaceTree(
       setOpenTreeNodes((prev) => ({ ...prev, [id]: isOpen }));
       if (isOpen) {
         const node = treeModel.find(data, id) as SpaceTreeNode | null;
-        if (
-          node?.hasChildren &&
-          (!node.children || node.children.length === 0)
-        ) {
+        // Same "unloaded branch" predicate the realtime insert paths use
+        // (`isUnloadedBranch`) so the lazy-load gate and the realtime inserts
+        // (`insertByPosition` / `placeByPosition`) can never disagree about what
+        // counts as unloaded (#525). Note: local raw `insert` (DnD/create-page)
+        // does not yet route through it — see #525 follow-up.
+        if (treeModel.isUnloadedBranch(node)) {
           const fetched = await fetchAllAncestorChildren({
             pageId: id,
             spaceId: node.spaceId,

apps/client/src/features/page/tree/model/tree-model.test.ts

@@ -74,6 +74,48 @@ describe("treeModel.isDescendant", () => {
   });
 });
 
+// #525: the single "is this branch unloaded?" predicate shared by the lazy-load
+// gate and the insert paths. Unloaded == server says hasChildren but none are
+// present locally (canonical form `children: []`, also `undefined`). A parent
+// without hasChildren is genuinely empty, not unloaded.
+describe("treeModel.isUnloadedBranch", () => {
+  type PH = TreeNode<{ name: string; hasChildren?: boolean }>;
+  it("true for hasChildren + empty array (canonical unloaded form)", () => {
+    const n: PH = { id: "p", name: "P", hasChildren: true, children: [] };
+    expect(treeModel.isUnloadedBranch(n)).toBe(true);
+  });
+  it("true for hasChildren + undefined children", () => {
+    const n: PH = { id: "p", name: "P", hasChildren: true };
+    expect(treeModel.isUnloadedBranch(n)).toBe(true);
+  });
+  it("false for hasChildren + already-loaded children", () => {
+    const n: PH = {
+      id: "p",
+      name: "P",
+      hasChildren: true,
+      children: [{ id: "c", name: "C" }],
+    };
+    expect(treeModel.isUnloadedBranch(n)).toBe(false);
+  });
+  it("false for a genuinely-empty parent (no hasChildren)", () => {
+    expect(
+      treeModel.isUnloadedBranch({
+        id: "p",
+        name: "P",
+        hasChildren: false,
+        children: [],
+      } as PH),
+    ).toBe(false);
+    expect(
+      treeModel.isUnloadedBranch({ id: "p", name: "P" } as PH),
+    ).toBe(false);
+  });
+  it("false for null/undefined", () => {
+    expect(treeModel.isUnloadedBranch(null)).toBe(false);
+    expect(treeModel.isUnloadedBranch(undefined)).toBe(false);
+  });
+});
+
 describe("treeModel.visible", () => {
   it("returns only root nodes when no openIds", () => {
     const v = treeModel.visible(fixture, new Set());
@@ -197,43 +239,64 @@ describe("treeModel.insertByPosition", () => {
     ]);
   });
 
-  // #159 #1: inserting/moving a node under a parent whose children are NOT
-  // loaded (`children === undefined`, e.g. a collapsed page) must NOT materialize
-  // a partial `[node]` list — that would defeat the lazy-load gate and hide the
-  // parent's other real children. The node is left to be lazy-loaded; only
-  // `hasChildren` is flagged so the chevron appears.
-  it("does NOT materialize a child under an UNLOADED parent (children undefined)", () => {
-    type PH = TreeNode<{
-      name: string;
-      position?: string;
-      hasChildren?: boolean;
-    }>;
+  type PH = TreeNode<{
+    name: string;
+    position?: string;
+    hasChildren?: boolean;
+  }>;
+
+  // #159 #1 / #525: inserting/moving a node under an UNLOADED parent must NOT
+  // materialize a partial `[node]` list — that would defeat the lazy-load gate and
+  // hide the parent's other real children. The canonical unloaded form here is
+  // `children: []` + `hasChildren: true` (from `pageToTreeNode` /
+  // `pruneCollapsedChildren`), which the pre-#525 `=== undefined` guard MISSED.
+  // The node is left to be lazy-loaded; the chevron stays enabled.
+  it("does NOT materialize a child under an UNLOADED parent (children: [], hasChildren: true)", () => {
     const tree: PH[] = [
-      { id: "p", name: "P", position: "a0", hasChildren: false }, // children: undefined
+      { id: "p", name: "P", position: "a0", hasChildren: true, children: [] },
     ];
     const node: PH = { id: "x", name: "X", position: "a1" };
     const t = treeModel.insertByPosition(tree, "p", node);
     const parent = treeModel.find(t, "p");
     // The node was NOT inserted (children stay unloaded -> lazy-load fetches the
-    // full set, including this node, on expand).
-    expect(parent?.children).toBeUndefined();
+    // full set, including this node, on expand). MUTATION: the pre-#525 predicate
+    // `children === undefined` does not fire for `[]`, so it would insert `[x]`
+    // here and reredden this expectation.
+    expect(parent?.children).toEqual([]);
     expect(treeModel.find(t, "x")).toBeNull();
-    // ...but the chevron is enabled so the user can expand to load it.
+    // ...and the chevron stays enabled so the user can expand to load it.
     expect((parent as PH).hasChildren).toBe(true);
   });
 
-  it("DOES insert under a LOADED-but-empty parent (children: [])", () => {
-    type PH = TreeNode<{
-      name: string;
-      position?: string;
-      hasChildren?: boolean;
-    }>;
+  it("does NOT materialize a child under an UNLOADED parent (children undefined, hasChildren: true)", () => {
+    const tree: PH[] = [
+      { id: "p", name: "P", position: "a0", hasChildren: true }, // children: undefined
+    ];
+    const node: PH = { id: "x", name: "X", position: "a1" };
+    const t = treeModel.insertByPosition(tree, "p", node);
+    const parent = treeModel.find(t, "p");
+    expect(parent?.children).toBeUndefined();
+    expect(treeModel.find(t, "x")).toBeNull();
+    expect((parent as PH).hasChildren).toBe(true);
+  });
+
+  it("DOES insert under a genuinely-empty parent (children: [], hasChildren: false)", () => {
     const tree: PH[] = [
       { id: "p", name: "P", position: "a0", hasChildren: false, children: [] },
     ];
     const node: PH = { id: "x", name: "X", position: "a1" };
     const t = treeModel.insertByPosition(tree, "p", node);
-    // A loaded (empty) child list is complete, so the node IS inserted.
+    // No server children (`hasChildren: false`), so materializing the first child
+    // is correct — nothing is hidden.
+    expect(treeModel.find(t, "p")?.children?.map((n) => n.id)).toEqual(["x"]);
+  });
+
+  it("DOES insert under a genuinely-empty parent (children undefined, hasChildren: false)", () => {
+    const tree: PH[] = [
+      { id: "p", name: "P", position: "a0", hasChildren: false }, // children: undefined
+    ];
+    const node: PH = { id: "x", name: "X", position: "a1" };
+    const t = treeModel.insertByPosition(tree, "p", node);
     expect(treeModel.find(t, "p")?.children?.map((n) => n.id)).toEqual(["x"]);
   });
 

apps/client/src/features/page/tree/model/tree-model.ts

@@ -43,6 +43,26 @@ export const treeModel = {
     };
   },
 
+  // A branch is "unloaded" when the server says it HAS children (`hasChildren`)
+  // but none are present locally. The canonical unloaded form in this codebase
+  // is `children: []` (produced by `pageToTreeNode` and by `pruneCollapsedChildren`
+  // resetting collapsed branches), NOT `children: undefined` — so a predicate that
+  // only checks `=== undefined` misses the real case and materializes a misleading
+  // partial list (#525). This is the SINGLE source of truth for "should a
+  // fetch/materialize be deferred?", shared by the lazy-load gate (`handleToggle`)
+  // and the realtime insert paths (`insertByPosition` / `placeByPosition`), so they
+  // can never drift apart again. (The local raw `insert` primitive and its DnD/
+  // create-page callers do NOT yet route through this predicate — see #525
+  // follow-up.) A parent WITHOUT `hasChildren` is genuinely empty
+  // (no server children) — inserting its first child is correct, not deferred.
+  isUnloadedBranch<T extends object>(
+    node: TreeNode<T> | null | undefined,
+  ): boolean {
+    if (!node) return false;
+    const hasChildren = (node as { hasChildren?: boolean }).hasChildren === true;
+    return hasChildren && (node.children == null || node.children.length === 0);
+  },
+
   isDescendant<T extends object>(
     tree: TreeNode<T>[],
     ancestorId: string,
@@ -127,14 +147,15 @@ export const treeModel = {
     }
     const parent = treeModel.find(tree, parentId);
     // The parent is in the tree but its children have NOT been lazy-loaded yet
-    // (`children === undefined`, distinct from a loaded-but-empty `[]`). Inserting
+    // (`hasChildren` set + children absent/empty — see `isUnloadedBranch`; the
+    // canonical unloaded form is `children: []`, NOT just `undefined`). Inserting
     // here would MATERIALIZE a misleading partial child list (`[node]`) that
     // defeats the lazy-load gate — which fetches only when children are
     // absent/empty — so the parent's OTHER real children would never load and the
     // moved/added node would be the only one shown (a silent data loss, #159 #1).
     // Instead, leave the children unloaded and just flag `hasChildren` so the
     // chevron appears; expanding fetches the FULL set (including this node).
-    if (parent && parent.children === undefined) {
+    if (parent && treeModel.isUnloadedBranch(parent)) {
       return treeModel.update(
         tree,
         parentId,

apps/client/src/features/search/components/search-spotlight.tsx

@@ -1,6 +1,6 @@
 import { Spotlight } from "@mantine/spotlight";
 import { IconSearch } from "@tabler/icons-react";
-import { Group, VisuallyHidden } from "@mantine/core";
+import { Group, Text, VisuallyHidden } from "@mantine/core";
 import { useState, useMemo } from "react";
 import { useDebouncedValue } from "@mantine/hooks";
 import { useTranslation } from "react-i18next";
@@ -84,6 +84,11 @@ export function SearchSpotlight({ spaceId }: SearchSpotlightProps) {
             onFiltersChange={handleFiltersChange}
             spaceId={spaceId}
           />
+          {/* #529: operator hint — matches ANY word by default; "…" for an exact
+              phrase, +term to require, -term to exclude. */}
+          <Text size="xs" c="dimmed" mt={4}>
+            {t('Tip: "exact phrase", +required, -excluded')}
+          </Text>
         </div>
 
         <VisuallyHidden role="status" aria-live="polite">

apps/client/src/features/search/types/search.types.ts

@@ -5,6 +5,9 @@ import { IPage } from "@/features/page/types/page.types.ts";
 
 export interface IPageSearch {
   id: string;
+  // #529 A7 superset: `pageId` aliases `id`; `rank`/`highlight` are null for
+  // substring-only hits (the UI already falls back to the title/snippet).
+  pageId?: string;
   title: string;
   icon: string;
   parentPageId: string;
@@ -12,9 +15,36 @@ export interface IPageSearch {
   creatorId: string;
   createdAt: Date;
   updatedAt: Date;
-  rank: string;
-  highlight: string;
+  rank: string | number | null;
+  highlight: string | null;
   space: Partial<ISpace>;
+  // New #529 fields (present from the native Postgres search driver).
+  snippet?: string;
+  score?: number;
+  path?: string[];
+  matchedFields?: string[];
+  matchedTerms?: string[];
+}
+
+// #529 A5 pagination envelope returned by POST /search (native driver). The web
+// list helpers read `items`; these travel alongside for pagination + diagnostics.
+export interface IPageSearchResponse {
+  items: IPageSearch[];
+  total: number;
+  hasMore: boolean;
+  truncatedAtCap: boolean;
+  offset: number;
+  query?: {
+    raw: string;
+    parsed: {
+      positive: string[];
+      required: string[];
+      excluded: string[];
+      reason?: string;
+    };
+    mode: "or" | "and";
+    match: string;
+  };
 }
 
 export interface SearchSuggestionParams {
@@ -37,6 +67,10 @@ export interface IPageSearchParams {
   query: string;
   spaceId?: string;
   shareId?: string;
+  // #529 A9: match mode (auto default) + pagination.
+  match?: "auto" | "word" | "prefix" | "substring";
+  limit?: number;
+  offset?: number;
 }
 
 export interface IAttachmentSearch {

apps/client/src/features/share/components/share-ai-widget.tsx

@@ -168,6 +168,10 @@ export default function ShareAiWidget({
             // Anonymous reader: suppress the tool-argument summary line so the
             // agent's raw query/argument text isn't shown on the public share.
             showInput={false}
+            // Anonymous reader: never paint a tool's raw errorText (it can carry
+            // internal detail). This is the render gate; the bytes are also
+            // sanitized server-side in PublicShareChatToolsService.forShare (#394).
+            showErrors={false}
             // Anonymous reader: neutralize internal/relative links in the
             // assistant's markdown so internal UUIDs/auth-gated routes don't
             // leak as clickable links (external http(s) links are kept).

apps/client/src/features/share/components/share-alias-section.test.tsx

@@ -13,8 +13,7 @@ let currentAlias: IShareAlias | null = null;
 let availabilityResult: {
   valid: boolean;
   available: boolean;
-  currentPageId: string | null;
-} = { valid: true, available: true, currentPageId: null };
+} = { valid: true, available: true };
 
 vi.mock("@/features/share/queries/share-query.ts", () => ({
   useShareAliasForPageQuery: () => ({ data: currentAlias }),
@@ -56,7 +55,7 @@ describe("ShareAliasSection — taken-name handling is never a dead end", () =>
   beforeEach(() => {
     setMutateAsync.mockReset();
     currentAlias = null;
-    availabilityResult = { valid: true, available: true, currentPageId: null };
+    availabilityResult = { valid: true, available: true };
   });
 
   it("shows a 'will move it here' HINT (not a terminal error) when the name belongs to another page, and keeps Save enabled", async () => {
@@ -65,7 +64,6 @@ describe("ShareAliasSection — taken-name handling is never a dead end", () =>
     availabilityResult = {
       valid: true,
       available: false,
-      currentPageId: "page-X",
     };
 
     renderSection("page-Y");
@@ -97,7 +95,6 @@ describe("ShareAliasSection — taken-name handling is never a dead end", () =>
     availabilityResult = {
       valid: true,
       available: false,
-      currentPageId: "page-X",
     };
     // The server rejects the un-confirmed save asking the client to confirm.
     setMutateAsync.mockRejectedValueOnce({
@@ -106,7 +103,6 @@ describe("ShareAliasSection — taken-name handling is never a dead end", () =>
         status: 409,
         data: {
           code: "ALIAS_REASSIGN_REQUIRED",
-          currentPageId: "page-X",
           currentPageTitle: "Alias Test Page X",
         },
       },

apps/client/src/features/share/components/share-alias-section.tsx

@@ -48,7 +48,6 @@ export default function ShareAliasSection({
   const [availability, setAvailability] = useState<{
     valid: boolean;
     available: boolean;
-    currentPageId: string | null;
   } | null>(null);
   const [reassign, setReassign] = useState<{
     alias: string;
@@ -76,7 +75,6 @@ export default function ShareAliasSection({
         setAvailability({
           valid: res.valid,
           available: res.available,
-          currentPageId: res.currentPageId,
         });
       } catch {
         setAvailability(null);

apps/client/src/features/share/types/share.types.ts

@@ -108,7 +108,6 @@ export interface IShareAliasAvailability {
   alias: string;
   valid: boolean;
   available: boolean;
-  currentPageId: string | null;
 }
 
 export interface ISharedPageTree {

apps/client/src/features/user/guarded-reload.test.tsx

@@ -0,0 +1,195 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { render, act, cleanup } from "@testing-library/react";
+import { MemoryRouter, useNavigate } from "react-router-dom";
+
+// Mocks for the dirty shell's side-effecting collaborators.
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: vi.fn() },
+}));
+vi.mock("@/i18n.ts", () => ({ default: { t: (k: string) => k } }));
+vi.mock("@/lib/reload-guard", () => ({
+  hasAutoReloaded: vi.fn(() => false),
+  markAutoReloaded: vi.fn(() => true),
+  recordReloadBreadcrumb: vi.fn(),
+  takeReloadBreadcrumb: vi.fn(() => null),
+}));
+
+import { notifications } from "@mantine/notifications";
+import { hasAutoReloaded, markAutoReloaded } from "@/lib/reload-guard";
+import {
+  triggerGuardedReload,
+  useVersionReloadOnNavigation,
+  __resetGuardedReloadForTests,
+} from "./guarded-reload";
+
+const show = notifications.show as unknown as ReturnType<typeof vi.fn>;
+const mockHasAutoReloaded = hasAutoReloaded as unknown as ReturnType<
+  typeof vi.fn
+>;
+const mockMarkAutoReloaded = markAutoReloaded as unknown as ReturnType<
+  typeof vi.fn
+>;
+
+let reload: ReturnType<typeof vi.fn>;
+let visibility: DocumentVisibilityState;
+
+// Test harness mounted inside a router: it installs the navigation hook and
+// exposes `navigate` so a test can drive an in-app router navigation.
+let doNavigate: (to: string) => void;
+function Harness() {
+  useVersionReloadOnNavigation();
+  const navigate = useNavigate();
+  doNavigate = navigate;
+  return null;
+}
+
+function mountHarness() {
+  render(
+    <MemoryRouter initialEntries={["/start"]}>
+      <Harness />
+    </MemoryRouter>,
+  );
+}
+
+function navigateTo(path: string) {
+  act(() => {
+    doNavigate(path);
+  });
+}
+
+beforeEach(() => {
+  __resetGuardedReloadForTests();
+  vi.clearAllMocks();
+  mockHasAutoReloaded.mockReturnValue(false);
+  mockMarkAutoReloaded.mockReturnValue(true);
+
+  vi.stubGlobal("APP_VERSION", "test-A");
+
+  reload = vi.fn();
+  Object.defineProperty(window, "location", {
+    configurable: true,
+    value: { reload },
+  });
+
+  visibility = "visible";
+  Object.defineProperty(document, "visibilityState", {
+    configurable: true,
+    get: () => visibility,
+  });
+});
+
+afterEach(() => {
+  cleanup();
+  vi.unstubAllGlobals();
+});
+
+describe("triggerGuardedReload (variant C)", () => {
+  it("noop when versions match: no banner, no reload", () => {
+    triggerGuardedReload("test-A");
+    expect(show).not.toHaveBeenCalled();
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("noop when the server version is empty (fail-safe)", () => {
+    triggerGuardedReload("");
+    triggerGuardedReload(undefined);
+    expect(show).not.toHaveBeenCalled();
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("real mismatch shows the banner but does NOT reload immediately", () => {
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(show).toHaveBeenCalledTimes(1);
+    expect(show.mock.calls[0][0]).toMatchObject({
+      id: "app-version-reload",
+      autoClose: false,
+      withCloseButton: true,
+    });
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("reloads EXACTLY ONCE on the first in-app navigation after a mismatch", () => {
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(reload).not.toHaveBeenCalled();
+
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+
+    // A second navigation must NOT reload again (one-shot was consumed).
+    navigateTo("/again");
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("does NOT reload on a 2nd mismatch after the first was armed/consumed (one-shot)", () => {
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+
+    // Another app-version mismatch arrives (reconnect): must not re-arm.
+    triggerGuardedReload("test-C");
+    navigateTo("/again");
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("does NOT reload merely from the tab going to the background", () => {
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(reload).not.toHaveBeenCalled();
+
+    visibility = "hidden";
+    act(() => {
+      document.dispatchEvent(new Event("visibilitychange"));
+    });
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("a hidden-at-receipt tab is also NOT reloaded immediately (variant C uniform); reloads on next navigation", () => {
+    visibility = "hidden";
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(reload).not.toHaveBeenCalled();
+    expect(show).toHaveBeenCalledTimes(1);
+
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("the banner's Update button reloads immediately", () => {
+    triggerGuardedReload("test-B");
+    const message = show.mock.calls[0][0].message as {
+      props: { onClick: () => void };
+    };
+    message.props.onClick();
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("banner-only (auto-reload already spent): banner, never auto-reload on navigation", () => {
+    mockHasAutoReloaded.mockReturnValue(true);
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(show).toHaveBeenCalledTimes(1);
+
+    navigateTo("/next");
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("does NOT reload when the flag write fails; falls back to the banner", () => {
+    mockMarkAutoReloaded.mockReturnValue(false);
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).not.toHaveBeenCalled();
+    // performAutoReload falls back to showing the banner (initial + fallback).
+    expect(show).toHaveBeenCalled();
+  });
+
+  it("is idempotent within a tab-load: repeated emits do not stack banners", () => {
+    triggerGuardedReload("test-B");
+    triggerGuardedReload("test-B");
+    triggerGuardedReload("test-C");
+    expect(show).toHaveBeenCalledTimes(1);
+  });
+});

apps/client/src/features/user/guarded-reload.tsx

@@ -0,0 +1,188 @@
+import { useEffect, useRef } from "react";
+import { useLocation } from "react-router-dom";
+import { Button } from "@mantine/core";
+import { notifications } from "@mantine/notifications";
+import i18n from "@/i18n.ts";
+import {
+  hasAutoReloaded,
+  markAutoReloaded,
+  recordReloadBreadcrumb,
+  takeReloadBreadcrumb,
+} from "@/lib/reload-guard";
+import { decideVersionAction } from "@/features/user/version-coherence";
+
+// Dirty shell around the pure `decideVersionAction`: it reads globals
+// (APP_VERSION), touches sessionStorage via the shared reload-guard, drives the
+// Mantine notification, and arms the router-navigation reload hook. Kept
+// separate from the pure module so the decision stays unit-testable without a
+// DOM.
+
+// One fixed id so repeated app-version signals (e.g. every reconnect) update a
+// single banner instead of stacking a new one each time.
+const BANNER_ID = "app-version-reload";
+
+// Module-level idempotency for the current tab-load: once a mismatch has been
+// handled we don't re-arm the navigation reload or re-show the banner on
+// subsequent app-version emits.
+let handled = false;
+
+// Variant C: on a real mismatch we do NOT reload the tab when it merely goes to
+// the background (that would silently drop a half-written comment/form). Instead
+// we arm a one-shot reload for the NEXT in-app router navigation — a point where
+// the user is already leaving the current page, so an in-app navigation would
+// discard that unsaved component-state anyway and the reload adds no extra loss.
+let pendingNavReload = false;
+
+// Remembered from the last detected mismatch for the pre-reload breadcrumb and
+// the (already-visible) banner.
+let lastServerVersion = "";
+let lastClientVersion = "";
+
+// Read the build version baked into THIS bundle. The `typeof` guard avoids a
+// ReferenceError where the `APP_VERSION` global is absent (e.g. under vitest,
+// where Vite's `define` did not run) — an unknown client version makes the
+// pure decision no-op (fail-safe).
+function readClientVersion(): string {
+  return (typeof APP_VERSION !== "undefined" ? APP_VERSION : "").trim();
+}
+
+// Perform the actual reload — but only after the shared one-shot flag is
+// persisted. If the write fails (storage unavailable) we must NOT reload
+// (mirrors the reactive chunk-load boundary's `catch → return`), and fall back
+// to the manual banner so the user can still recover.
+function performAutoReload(): void {
+  if (!markAutoReloaded()) {
+    showReloadBanner();
+    return;
+  }
+  // Trace right before the reload (which clears the console): a persistent
+  // breadcrumb + a log line so the auto-reload is observable in a field report.
+  recordReloadBreadcrumb({
+    path: "proactive",
+    serverVersion: lastServerVersion,
+    clientVersion: lastClientVersion,
+  });
+  console.warn(
+    `[version-coherence] auto-reloading: client=${lastClientVersion} -> server=${lastServerVersion}`,
+  );
+  window.location.reload();
+}
+
+function showReloadBanner(): void {
+  notifications.show({
+    id: BANNER_ID,
+    title: i18n.t("A new version is available"),
+    message: (
+      <Button size="xs" mt="xs" onClick={() => performAutoReload()}>
+        {i18n.t("Update")}
+      </Button>
+    ),
+    autoClose: false,
+    withCloseButton: true,
+  });
+}
+
+/**
+ * Handle a server `app-version` announcement: compare it to this bundle's
+ * version and, on a real mismatch, show the banner and arm a guarded reload for
+ * the next in-app navigation (variant C).
+ *
+ * - real mismatch (window budget available) → banner + arm navigation reload.
+ *   The banner's "Update" button reloads immediately (same shared window guard).
+ *   The tab is NOT reloaded on visibility change.
+ * - auto-reload already used this window / storage error → banner only (no arm),
+ *   so there is at most one automatic reload per RELOAD_WINDOW_MS window (loop
+ *   safety).
+ * - in sync / unknown version → noop (fail-safe).
+ */
+export function triggerGuardedReload(
+  rawServerVersion: string | undefined | null,
+): void {
+  const serverVersion = (rawServerVersion ?? "").trim();
+  const clientVersion = readClientVersion();
+
+  // A storage read error surfaces as autoReloadUsed=true → fail toward NOT
+  // reloading (banner only).
+  const autoReloadUsed = hasAutoReloaded();
+
+  const action = decideVersionAction({
+    serverVersion,
+    clientVersion,
+    autoReloadUsed,
+  });
+  if (action === "noop") return;
+
+  // Idempotent per tab-load: don't re-arm or re-stack the banner across repeated
+  // emits (reconnects) once we've already acted.
+  if (handled) return;
+  handled = true;
+
+  lastServerVersion = serverVersion;
+  lastClientVersion = clientVersion;
+
+  if (action === "banner") {
+    // Entered banner-only (permanent skew, node oscillation, or the window's
+    // auto-reload budget already spent). Log for diagnosability; show the banner.
+    console.warn(
+      `[version-coherence] server=${serverVersion} client=${clientVersion}: ` +
+        "auto-reload budget already spent this window — showing manual banner",
+    );
+    showReloadBanner();
+    return;
+  }
+
+  // action === "reload" (variant C): show the banner and defer the auto-reload
+  // to the next in-app navigation instead of reloading now / on visibility.
+  showReloadBanner();
+  pendingNavReload = true;
+}
+
+/**
+ * Consume the armed one-shot navigation reload, if any. Called by
+ * `useVersionReloadOnNavigation` on each in-app router navigation.
+ */
+export function consumeNavigationReload(): void {
+  if (!pendingNavReload) return;
+  pendingNavReload = false;
+  performAutoReload();
+}
+
+/**
+ * Hook (mounted inside the Router) that fires the armed one-shot reload on the
+ * NEXT in-app router navigation after a version mismatch. Skips the initial
+ * render so it only reacts to real navigations, not the first location.
+ */
+export function useVersionReloadOnNavigation(): void {
+  const location = useLocation();
+  const firstRender = useRef(true);
+  useEffect(() => {
+    if (firstRender.current) {
+      firstRender.current = false;
+      return;
+    }
+    consumeNavigationReload();
+  }, [location.key]);
+}
+
+/**
+ * Surface (log once) the breadcrumb left by an auto-reload in the previous page
+ * load — the reload cleared the console, so this makes a "tab reloaded itself"
+ * report diagnosable. Call once on app startup.
+ */
+export function surfacePreviousReloadBreadcrumb(): void {
+  const crumb = takeReloadBreadcrumb();
+  if (!crumb) return;
+  console.info(
+    `[version-coherence] previous auto-reload: path=${crumb.path} ` +
+      `client=${crumb.clientVersion ?? ""} -> server=${crumb.serverVersion ?? ""} ` +
+      `at=${new Date(crumb.at).toISOString()}`,
+  );
+}
+
+// Test-only: reset module-level latches between cases.
+export function __resetGuardedReloadForTests(): void {
+  handled = false;
+  pendingNavReload = false;
+  lastServerVersion = "";
+  lastClientVersion = "";
+}

apps/client/src/features/user/reload-budget.integration.test.tsx

@@ -0,0 +1,171 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { render, act, cleanup } from "@testing-library/react";
+import { MemoryRouter, useNavigate } from "react-router-dom";
+
+// Integration test for the SHARED, window-based auto-reload budget (invariant a):
+// the reactive chunk-load boundary and the proactive version-coherence path both
+// route through the REAL @/lib/reload-guard, so at most one automatic reload
+// happens per RELOAD_WINDOW_MS across BOTH paths combined. Only the two paths'
+// side-effecting collaborators are mocked — the reload guard is intentionally
+// REAL so this exercises the actual shared sessionStorage budget.
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: vi.fn() },
+}));
+vi.mock("@/i18n.ts", () => ({ default: { t: (k: string) => k } }));
+
+import { handleError } from "@/components/chunk-load-error-boundary";
+import {
+  triggerGuardedReload,
+  useVersionReloadOnNavigation,
+  __resetGuardedReloadForTests,
+} from "./guarded-reload";
+import { RELOAD_WINDOW_MS } from "@/lib/reload-guard";
+
+const CHUNK_ERROR = { name: "ChunkLoadError", message: "boom" };
+const T0 = 1_000_000_000_000;
+
+let reload: ReturnType<typeof vi.fn>;
+let nowMock: ReturnType<typeof vi.spyOn>;
+
+// Harness mounted inside a router: installs the navigation hook and exposes
+// `navigate` so a test can drive an in-app router navigation (the point where the
+// proactive path fires its armed reload).
+let doNavigate: (to: string) => void;
+function Harness() {
+  useVersionReloadOnNavigation();
+  doNavigate = useNavigate();
+  return null;
+}
+function mountHarness() {
+  render(
+    <MemoryRouter initialEntries={["/start"]}>
+      <Harness />
+    </MemoryRouter>,
+  );
+}
+function navigateTo(path: string) {
+  act(() => {
+    doNavigate(path);
+  });
+}
+function setNow(t: number) {
+  nowMock.mockReturnValue(t);
+}
+
+beforeEach(() => {
+  sessionStorage.clear();
+  __resetGuardedReloadForTests();
+  vi.clearAllMocks();
+  nowMock = vi.spyOn(Date, "now").mockReturnValue(T0);
+  vi.stubGlobal("APP_VERSION", "test-A");
+  reload = vi.fn();
+  Object.defineProperty(window, "location", {
+    configurable: true,
+    value: { reload },
+  });
+});
+
+afterEach(() => {
+  cleanup();
+  vi.unstubAllGlobals();
+  vi.restoreAllMocks();
+  sessionStorage.clear();
+});
+
+describe("shared window-based reload budget (invariant a)", () => {
+  it("a chunk-load reload spends the budget: a version-coherence mismatch within the window shows the banner but does NOT reload", () => {
+    // Path 1 (reactive): a stale-chunk 404 auto-reloads once and stamps the window.
+    handleError(CHUNK_ERROR);
+    expect(reload).toHaveBeenCalledTimes(1);
+    reload.mockClear();
+
+    // Path 2 (proactive), 1 min later — still inside the window. The shared budget
+    // is spent, so the version mismatch degrades to the banner and never reloads.
+    setNow(T0 + 60_000);
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("a version-coherence reload spends the SAME budget: a chunk-load error within the window does NOT reload", () => {
+    // Path 2 (proactive) first: real mismatch → arm → fire on navigation.
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+    reload.mockClear();
+
+    // Path 1 (reactive), 2 min later — inside the window. Budget already spent by
+    // the proactive path, so the stale-chunk error must NOT trigger a second reload.
+    setNow(T0 + 2 * 60_000);
+    handleError(CHUNK_ERROR);
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("recovers after the window: a reload strictly older than the window is allowed again (second deploy)", () => {
+    // First auto-reload (reactive) stamps the window.
+    handleError(CHUNK_ERROR);
+    expect(reload).toHaveBeenCalledTimes(1);
+    reload.mockClear();
+
+    // A second deploy arrives after the window has fully elapsed → the proactive
+    // path is allowed to reload again (window, not a permanent one-shot).
+    __resetGuardedReloadForTests();
+    setNow(T0 + RELOAD_WINDOW_MS + 1);
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("reactive path fails closed when storage READS but cannot WRITE (quota / Safari private): no unguarded reload", () => {
+    // getItem→null makes hasAutoReloaded() report the budget as available, so
+    // handleError passes the first guard and reaches `if (!markAutoReloaded())
+    // return;`. setItem throws → the stamp cannot stick, so markAutoReloaded()
+    // returns false and that guard MUST bail — otherwise the reactive path would
+    // reload on every stale-chunk error with no persisted budget (an unguarded
+    // loop). This is the asymmetric gap: the proactive path's equivalent is
+    // covered by guarded-reload.test.tsx "does NOT reload when the flag write
+    // fails".
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => null,
+      setItem: () => {
+        throw new Error("quota exceeded");
+      },
+      removeItem: () => {},
+      clear: () => {},
+    });
+    try {
+      handleError(CHUNK_ERROR);
+      expect(reload).not.toHaveBeenCalled();
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+
+  it("sessionStorage unavailable: neither path performs an unguarded reload", () => {
+    // The real guard fails toward NOT reloading when storage throws.
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => {
+        throw new Error("storage disabled");
+      },
+      setItem: () => {
+        throw new Error("storage disabled");
+      },
+      removeItem: () => {},
+      clear: () => {},
+    });
+    try {
+      handleError(CHUNK_ERROR);
+      expect(reload).not.toHaveBeenCalled();
+
+      mountHarness();
+      triggerGuardedReload("test-B");
+      navigateTo("/next");
+      expect(reload).not.toHaveBeenCalled();
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+});

apps/client/src/features/user/user-provider.tsx

@@ -13,6 +13,12 @@ import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
 import { Error404 } from "@/components/ui/error-404.tsx";
 import { queryClient } from "@/main.tsx";
 import { makeConnectHandler } from "@/features/user/connect-resync.ts";
+import {
+  triggerGuardedReload,
+  useVersionReloadOnNavigation,
+  surfacePreviousReloadBreadcrumb,
+} from "@/features/user/guarded-reload.tsx";
+import type { AppVersionSocketPayload } from "@/features/user/version-coherence.ts";
 
 export function UserProvider({ children }: React.PropsWithChildren) {
   const [, setCurrentUser] = useAtom(currentUserAtom);
@@ -22,6 +28,16 @@ export function UserProvider({ children }: React.PropsWithChildren) {
   // fetch collab token on load
   const { data: collab } = useCollabToken();
 
+  // version-coherence: fire the armed one-shot reload on the next in-app
+  // navigation (variant C — a safe point, not on tab backgrounding).
+  useVersionReloadOnNavigation();
+
+  // Surface any breadcrumb left by an auto-reload in the previous page load
+  // (the reload cleared the console) so a field report stays diagnosable.
+  useEffect(() => {
+    surfacePreviousReloadBreadcrumb();
+  }, []);
+
   useEffect(() => {
     if (isLoading || isError) {
       return;
@@ -47,6 +63,16 @@ export function UserProvider({ children }: React.PropsWithChildren) {
       handleConnect();
     });
 
+    // Register the version-coherence listener SYNCHRONOUSLY, before the socket
+    // connects: the server emits `app-version` immediately in handleConnection,
+    // so a listener attached after connect would miss it on a fast localhost
+    // connect. On a version mismatch the client shows a banner and defers the
+    // auto-reload to the next in-app navigation (variant C — avoids reloading a
+    // backgrounded tab that may hold unsaved input) before it hits a stale chunk.
+    newSocket.on("app-version", (payload?: AppVersionSocketPayload) => {
+      triggerGuardedReload(payload?.version);
+    });
+
     return () => {
       console.log("ws disconnected");
       newSocket.disconnect();

apps/client/src/features/user/version-coherence.test.ts

@@ -0,0 +1,64 @@
+import { describe, it, expect } from "vitest";
+import { decideVersionAction } from "./version-coherence";
+
+describe("decideVersionAction", () => {
+  it("noop when the server version is empty (fail-safe)", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "",
+        clientVersion: "v1",
+        autoReloadUsed: false,
+      }),
+    ).toBe("noop");
+  });
+
+  it("noop when the client version is empty (fail-safe)", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "v1",
+        clientVersion: "",
+        autoReloadUsed: false,
+      }),
+    ).toBe("noop");
+  });
+
+  it("noop when versions are equal (in sync)", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "v1",
+        clientVersion: "v1",
+        autoReloadUsed: false,
+      }),
+    ).toBe("noop");
+  });
+
+  it("reload on a real mismatch the first time this session", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "test-B",
+        clientVersion: "test-A",
+        autoReloadUsed: false,
+      }),
+    ).toBe("reload");
+  });
+
+  it("banner on a mismatch once the session auto-reload is spent", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "test-B",
+        clientVersion: "test-A",
+        autoReloadUsed: true,
+      }),
+    ).toBe("banner");
+  });
+
+  it("equal versions stay noop even if auto-reload was already used", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "v1",
+        clientVersion: "v1",
+        autoReloadUsed: true,
+      }),
+    ).toBe("noop");
+  });
+});

apps/client/src/features/user/version-coherence.ts

@@ -0,0 +1,32 @@
+// Payload of the per-connect `app-version` socket.io event announced by the
+// server (ws.gateway.ts) after a successful auth. A dedicated event — NOT a
+// member of the room-scoped `WebSocketEvent` union (which is discriminated by
+// `operation`), so it never touches use-query-subscription.
+export type AppVersionSocketPayload = { version: string };
+
+/**
+ * Pure decision for the version-coherence guard.
+ *
+ * All inputs are injected (no globals, no side effects) so it is unit-testable
+ * without a DOM or the build-time `APP_VERSION` global (undefined under vitest).
+ *
+ * - `autoReloadUsed` = an automatic reload has already happened within the
+ *   current ~5-min window, so we must not auto-reload again (loop safety,
+ *   shared window budget with the reactive chunk-load boundary).
+ *
+ * Returns:
+ * - "noop"   — do nothing (unknown version on either side, or already in sync).
+ * - "banner" — show the manual "update available" banner only (no auto-reload).
+ * - "reload" — real first-time mismatch: eligible for a guarded auto-reload.
+ */
+export function decideVersionAction(args: {
+  serverVersion: string;
+  clientVersion: string;
+  autoReloadUsed: boolean;
+}): "reload" | "banner" | "noop" {
+  const { serverVersion, clientVersion, autoReloadUsed } = args;
+  if (!serverVersion || !clientVersion) return "noop"; // fail-safe: unknown version → never act
+  if (serverVersion === clientVersion) return "noop"; // in sync
+  if (autoReloadUsed) return "banner"; // one auto-reload per RELOAD_WINDOW_MS window already spent
+  return "reload"; // real mismatch, window budget available
+}

apps/client/src/features/websocket/tree-socket-reducers.test.ts

@@ -82,17 +82,19 @@ describe("applyMoveTreeNode", () => {
     ]);
   });
 
-  it("does NOT create a partial child list when the destination is loaded-but-collapsed (children unloaded) — keeps it lazy-loadable (#159)", () => {
-    // `dstCollapsed` is in the tree but its children were never lazy-loaded
-    // (children === undefined). The OLD behavior inserted `src` as the ONLY
-    // child ([src]), which defeated the lazy-load gate and HID the parent's
-    // other real children. Now the move leaves children unloaded (so expanding
-    // fetches the FULL set, including src) and just flags hasChildren.
+  it("does NOT create a partial child list when the destination is loaded-but-collapsed (children unloaded) — keeps it lazy-loadable (#159 #525)", () => {
+    // `dstCollapsed` is in the tree but its children were never lazy-loaded. The
+    // CANONICAL unloaded form here is `hasChildren: true` + `children: []` (from
+    // `pageToTreeNode` / `pruneCollapsedChildren`), NOT `children: undefined`.
+    // The pre-#525 predicate (`children === undefined`) missed this form and
+    // inserted `src` as the ONLY child ([src]), defeating the lazy-load gate and
+    // HIDING the parent's other real children. Now the move leaves children
+    // unloaded (so expanding fetches the FULL set, including src).
     const tree: SpaceTreeNode[] = [
       node("dstCollapsed", {
         position: "a0",
-        hasChildren: false,
-        children: undefined as unknown as SpaceTreeNode[],
+        hasChildren: true,
+        children: [],
       }),
       node("src", { position: "a9" }),
     ];
@@ -105,9 +107,10 @@ describe("applyMoveTreeNode", () => {
       pageData: {},
     });
     const dst = treeModel.find(next, "dstCollapsed");
-    // Children stay unloaded -> the lazy-load gate fetches the FULL set (incl.
-    // src) on expand, rather than showing a misleading partial [src] list.
-    expect(dst?.children).toBeUndefined();
+    // Children stay unloaded ([] not materialized to [src]) -> the lazy-load gate
+    // fetches the FULL set (incl. src) on expand. MUTATION: the pre-#525
+    // `=== undefined` predicate would insert [src] here and redden this.
+    expect(dst?.children).toEqual([]);
     expect(dst?.hasChildren).toBe(true);
     // src moved away from its old root slot (it lives under dstCollapsed
     // server-side and reappears when the parent is expanded/loaded).

apps/client/src/features/workspace/components/settings/components/ai-mcp-server-form.tsx

@@ -28,6 +28,7 @@ import {
   IAiMcpServerCreate,
   IAiMcpServerUpdate,
 } from "@/features/workspace/services/ai-mcp-server-service.ts";
+import { resolveToolAllowlist } from "./ai-mcp-server-form.utils.ts";
 
 const formSchema = z.object({
   name: z.string().min(1),
@@ -121,13 +122,20 @@ export default function AiMcpServerForm({
   async function handleSubmit(values: FormValues) {
     const headers = resolveHeaders();
 
+    // An empty tag field means "no restriction" (sent as null) — since #476 the
+    // server persists a literal `[]` as deny-all (zero tools). But a server that
+    // was ALREADY deny-all loads into an empty field too; sending null there
+    // would silently widen it to allow-all on a routine edit, so preserve `[]`.
+    // See resolveToolAllowlist for the full rationale.
+    const toolAllowlist = resolveToolAllowlist(values.toolAllowlist, server);
+
     if (isEdit && server) {
       const payload: IAiMcpServerUpdate = {
         id: server.id,
         name: values.name,
         transport: values.transport,
         url: values.url,
-        toolAllowlist: values.toolAllowlist,
+        toolAllowlist,
         // Always sent: a blank value clears the stored guidance (server -> null).
         instructions: values.instructions,
         enabled: values.enabled,
@@ -140,7 +148,7 @@ export default function AiMcpServerForm({
         name: values.name,
         transport: values.transport,
         url: values.url,
-        toolAllowlist: values.toolAllowlist,
+        toolAllowlist,
         // Blank => server stores null (no guidance).
         instructions: values.instructions,
         enabled: values.enabled,

apps/client/src/features/workspace/components/settings/components/ai-mcp-server-form.utils.test.ts

@@ -0,0 +1,29 @@
+import { describe, it, expect } from "vitest";
+import { resolveToolAllowlist } from "./ai-mcp-server-form.utils.ts";
+
+describe("resolveToolAllowlist", () => {
+  it("sends the typed tools when the field is non-empty", () => {
+    expect(resolveToolAllowlist(["a", "b"], { toolAllowlist: null })).toEqual([
+      "a",
+      "b",
+    ]);
+  });
+
+  it("creates as null (unrestricted) when empty and there is no server", () => {
+    expect(resolveToolAllowlist([], undefined)).toBeNull();
+  });
+
+  it("sends null for an empty field on a previously-unrestricted server", () => {
+    expect(resolveToolAllowlist([], { toolAllowlist: null })).toBeNull();
+  });
+
+  it("preserves deny-all: an empty field on a `[]` server stays `[]`, not null", () => {
+    // The core #476/#477 guard: editing a deny-all server (rename/toggle) with
+    // an empty tag field must NOT silently widen it to allow-all.
+    expect(resolveToolAllowlist([], { toolAllowlist: [] })).toEqual([]);
+  });
+
+  it("still sends explicit tools even if the server was deny-all", () => {
+    expect(resolveToolAllowlist(["x"], { toolAllowlist: [] })).toEqual(["x"]);
+  });
+});

apps/client/src/features/workspace/components/settings/components/ai-mcp-server-form.utils.ts

@@ -0,0 +1,22 @@
+import { IAiMcpServer } from "@/features/workspace/services/ai-mcp-server-service.ts";
+
+// Resolve the tool allowlist value to persist from the form field.
+//
+// An empty tag field normally means "no restriction" and is sent as null so
+// the server drops the column (all tools allowed). But a server that was
+// ALREADY deny-all (a stored literal `[]`, meaning zero tools — creatable via
+// the API) loads into the form as an empty field too. Coercing that empty
+// field to null on submit would SILENTLY widen a deny-all server to allow-all
+// on any routine edit (rename, toggle) — the exact silent-widen class #476
+// closed on the read side. So when the edited server was deny-all, preserve
+// `[]` (deny-all); only a genuinely-unrestricted server (stored null/absent)
+// stays null.
+export function resolveToolAllowlist(
+  fieldValue: string[],
+  server?: Pick<IAiMcpServer, "toolAllowlist">,
+): string[] | null {
+  if (fieldValue.length > 0) return fieldValue;
+  const wasDenyAll =
+    Array.isArray(server?.toolAllowlist) && server.toolAllowlist.length === 0;
+  return wasDenyAll ? [] : null;
+}

apps/client/src/features/workspace/components/settings/components/ai-provider-settings.spec.tsx

@@ -6,6 +6,8 @@ import {
   nextReindexPollInterval,
   isReindexComplete,
   isReindexButtonLoading,
+  reindexRunKey,
+  isNewReindexRun,
 } from './ai-provider-settings';
 
 describe('resolveCardStatus', () => {
@@ -221,6 +223,128 @@ describe('isReindexComplete', () => {
   });
 });
 
+describe('reindexRunKey', () => {
+  it('is null when the status carries no run identity', () => {
+    expect(reindexRunKey(undefined)).toBeNull();
+    expect(
+      reindexRunKey({ reindexing: false, indexedPages: 5, totalPages: 5 }),
+    ).toBeNull();
+  });
+
+  it('is null for a legacy/degraded record with an empty runId', () => {
+    // The server sends runId='' for a record written before the field existed;
+    // the client must treat that as "no identity" (fall back to prior behaviour).
+    expect(
+      reindexRunKey({
+        reindexing: true,
+        indexedPages: 0,
+        totalPages: 10,
+        runId: '',
+        reindexStartedAt: 1000,
+      }),
+    ).toBeNull();
+  });
+
+  it('folds runId and startedAt into one stable key', () => {
+    expect(
+      reindexRunKey({
+        reindexing: true,
+        indexedPages: 0,
+        totalPages: 10,
+        runId: 'run-a',
+        reindexStartedAt: 1000,
+      }),
+    ).toBe('run-a:1000');
+  });
+
+  it('changes when the runId changes for the same startedAt', () => {
+    const a = reindexRunKey({
+      reindexing: true,
+      indexedPages: 0,
+      totalPages: 10,
+      runId: 'run-a',
+      reindexStartedAt: 1000,
+    });
+    const b = reindexRunKey({
+      reindexing: true,
+      indexedPages: 0,
+      totalPages: 10,
+      runId: 'run-b',
+      reindexStartedAt: 1000,
+    });
+    expect(a).not.toBe(b);
+  });
+
+  it('changes when the same runId restarts at a new startedAt', () => {
+    const a = reindexRunKey({
+      reindexing: true,
+      indexedPages: 0,
+      totalPages: 10,
+      runId: 'run-a',
+      reindexStartedAt: 1000,
+    });
+    const b = reindexRunKey({
+      reindexing: true,
+      indexedPages: 0,
+      totalPages: 10,
+      runId: 'run-a',
+      reindexStartedAt: 2000,
+    });
+    expect(a).not.toBe(b);
+  });
+});
+
+describe('isNewReindexRun (poll keying on runId)', () => {
+  // Derive the status shape from the helper itself so the test needs no export
+  // of the component-internal ReindexStatus type.
+  type ReindexStatusLike = NonNullable<Parameters<typeof reindexRunKey>[0]>;
+  const run = (runId: string, startedAt: number): ReindexStatusLike => ({
+    reindexing: true,
+    indexedPages: 0,
+    totalPages: 10,
+    runId,
+    reindexStartedAt: startedAt,
+  });
+
+  it('first identity after none latched is a NEW run', () => {
+    expect(isNewReindexRun(null, run('run-a', 1000))).toBe(true);
+  });
+
+  it('the SAME identity is not a new run (same run being watched)', () => {
+    const key = reindexRunKey(run('run-a', 1000));
+    expect(isNewReindexRun(key, run('run-a', 1000))).toBe(false);
+  });
+
+  it('a DIFFERENT runId is a new run (reset per-run poll state)', () => {
+    const key = reindexRunKey(run('run-a', 1000));
+    expect(isNewReindexRun(key, run('run-b', 1000))).toBe(true);
+  });
+
+  it('an identity-less poll (no runId / cleared record) is never a new run', () => {
+    const key = reindexRunKey(run('run-a', 1000));
+    expect(
+      isNewReindexRun(key, {
+        reindexing: false,
+        indexedPages: 10,
+        totalPages: 10,
+      }),
+    ).toBe(false);
+  });
+
+  it('a legacy empty-runId poll does not spuriously reset a latched run', () => {
+    const key = reindexRunKey(run('run-a', 1000));
+    expect(
+      isNewReindexRun(key, {
+        reindexing: true,
+        indexedPages: 3,
+        totalPages: 10,
+        runId: '',
+        reindexStartedAt: 1000,
+      }),
+    ).toBe(false);
+  });
+});
+
 describe('isReindexButtonLoading', () => {
   it('loads while the POST mutation is pending', () => {
     expect(

apps/client/src/features/workspace/components/settings/components/ai-provider-settings.tsx

@@ -173,9 +173,43 @@ export function resolveKeyField(
 // Subset of the status payload that drives the reindex poll decisions.
 type ReindexStatus = Pick<
   IAiSettings,
-  "reindexing" | "indexedPages" | "totalPages"
+  "reindexing" | "indexedPages" | "totalPages" | "runId" | "reindexStartedAt"
 >;
 
+/**
+ * A stable per-RUN key for the reindex poll: `runId:startedAt`, or `null` when
+ * the status carries no run identity (no active run, or a legacy/degraded
+ * server record with an empty runId). Two polls of the SAME run share a key; a
+ * new run mints a fresh runId and so a different key.
+ *
+ * This is the single place the client turns the server's run identity into the
+ * value it keys on — it removes the "is this the same run I've been watching or
+ * a brand-new one?" ambiguity that made a class of reindex-status bugs (a stale
+ * pre-reindex snapshot vs a fresh run) get fixed twice (#262). `startedAt` is
+ * folded in so a run that somehow reuses a runId but restarted is still new.
+ */
+export function reindexRunKey(status: ReindexStatus | undefined): string | null {
+  const runId = status?.runId;
+  if (!runId) return null;
+  return `${runId}:${status?.reindexStartedAt ?? ""}`;
+}
+
+/**
+ * Decide whether the latest poll represents a NEW reindex run relative to the
+ * run key the client last latched (`prevKey`, `null` if none yet). True only
+ * when the status carries an identity AND it differs from the latched one — the
+ * signal to reset any per-run poll state (the "seen active" latch / progress the
+ * UI held). The same identity (or no identity) is NOT a new run, so an unchanged
+ * or identity-less poll never resets mid-run.
+ */
+export function isNewReindexRun(
+  prevKey: string | null,
+  status: ReindexStatus | undefined,
+): boolean {
+  const key = reindexRunKey(status);
+  return key !== null && key !== prevKey;
+}
+
 /**
  * Decide the TanStack Query `refetchInterval` while a reindex may be running.
  * Returns the poll interval (ms) to keep polling, or `false` to stop.
@@ -320,6 +354,13 @@ export default function AiProviderSettings() {
   // counter at 0 until a manual reload. A ref (not state) because it must not
   // trigger a render and is only ever read where `reindexing` is already false.
   const reindexSeenActiveRef = useRef(false);
+  // The run identity (runId:startedAt) the current poll window is keyed on. When
+  // a poll reports a DIFFERENT runId the server has started a NEW run, so we
+  // re-latch to it and reset `reindexSeenActiveRef` — a fresh run must never
+  // inherit the previous run's "seen active"/completion state (which would stop
+  // polling immediately or read the old run's counters as this run's). null =
+  // no run keyed yet (steady state, or a legacy record without a runId).
+  const reindexRunKeyRef = useRef<string | null>(null);
 
   // Only admins may read the (masked) AI settings; the server enforces this too.
   const { data: settings, isLoading } = useAiSettingsQuery(isAdmin, (query) =>
@@ -336,6 +377,14 @@ export default function AiProviderSettings() {
   // unmount because the deadline state goes away with the component.
   useEffect(() => {
     if (reindexDeadline === null) return;
+    // Key the poll on the run identity: if this poll carries a runId different
+    // from the one we latched, the server started a NEW run, so adopt it and
+    // drop the per-run "seen active" latch (a fresh run must not inherit the
+    // previous run's completion state). Same runId => same run, leave it alone.
+    if (isNewReindexRun(reindexRunKeyRef.current, settings)) {
+      reindexRunKeyRef.current = reindexRunKey(settings);
+      reindexSeenActiveRef.current = false;
+    }
     // Latch "we have seen the active run" the moment a poll reports it, so the
     // completion check below (and the refetchInterval's) only fires once the run
     // has genuinely started — never on the stale pre-reindex snapshot.
@@ -1220,6 +1269,10 @@ export default function AiProviderSettings() {
                   // immediately.
                   onSuccess: () => {
                     reindexSeenActiveRef.current = false;
+                    // Forget the previous run's identity so the first poll of
+                    // this window (carrying the new run's runId) is recognized
+                    // as a new run and keyed afresh.
+                    reindexRunKeyRef.current = null;
                     setReindexDeadline(Date.now() + REINDEX_POLL_CAP_MS);
                   },
                 })

apps/client/src/features/workspace/services/ai-mcp-server-service.ts

@@ -27,7 +27,9 @@ export interface IAiMcpServerCreate {
   // Auth headers map (e.g. { Authorization: 'Bearer ...' }). Encrypted on save;
   // never returned.
   headers?: Record<string, string>;
-  toolAllowlist?: string[];
+  // Omit/null => no restriction; `[]` is persisted verbatim and means
+  // deny-all (zero tools) since #476.
+  toolAllowlist?: string[] | null;
   // Admin-authored prompt guidance (#180). Blank => stored as null.
   instructions?: string;
   enabled?: boolean;
@@ -43,7 +45,9 @@ export interface IAiMcpServerUpdate {
   transport?: McpTransport;
   url?: string;
   headers?: Record<string, string>;
-  toolAllowlist?: string[];
+  // Absent => unchanged; null => no restriction; `[]` is persisted verbatim
+  // and means deny-all (zero tools) since #476.
+  toolAllowlist?: string[] | null;
   // Admin-authored prompt guidance (#180). Absent => unchanged; blank => cleared.
   instructions?: string;
   enabled?: boolean;

apps/client/src/features/workspace/services/ai-settings-service.ts

@@ -51,6 +51,14 @@ export interface IAiSettings {
   // True while a full workspace reindex is actively running; the counts above
   // then reflect the live run progress (done climbs 0 -> total).
   reindexing?: boolean;
+  // Identity of the ACTIVE reindex run (present only while `reindexing`). The
+  // poll keys on `runId`: a changed value means a NEW run (reset the per-run
+  // poll state the UI latched), the same value is the run already being watched.
+  // Absent/empty ('') => no identity available; the client keeps prior behaviour.
+  runId?: string;
+  // Epoch-ms the active run started; paired with `runId` so a restart with a
+  // recycled id is still detected as a new run.
+  reindexStartedAt?: number;
 }
 
 // Update payload. Key semantics (same for `apiKey` and `embeddingApiKey`):

apps/client/src/lib/reload-guard.test.ts

@@ -0,0 +1,145 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import {
+  hasAutoReloaded,
+  markAutoReloaded,
+  shouldAutoReload,
+  recordReloadBreadcrumb,
+  takeReloadBreadcrumb,
+  RELOAD_WINDOW_MS,
+} from "./reload-guard";
+
+// The shared budget is a single sessionStorage timestamp keyed here; both the
+// reactive chunk-load boundary and the proactive version-coherence path read and
+// stamp it, so at most one auto-reload happens per RELOAD_WINDOW_MS across BOTH.
+const RELOAD_AT_KEY = "chunk-reload-at";
+const NOW = 1_000_000_000_000;
+
+describe("reload-guard", () => {
+  beforeEach(() => {
+    sessionStorage.clear();
+    vi.restoreAllMocks();
+  });
+
+  afterEach(() => {
+    sessionStorage.clear();
+    vi.restoreAllMocks();
+  });
+
+  it("hasAutoReloaded is false before any reload, true within the window after mark", () => {
+    expect(hasAutoReloaded(NOW)).toBe(false);
+    expect(markAutoReloaded(NOW)).toBe(true);
+    // Same key both paths share; stores the reload timestamp, not a flag.
+    expect(sessionStorage.getItem(RELOAD_AT_KEY)).toBe(String(NOW));
+    // Inside the window → budget spent → true (fall through to manual UI).
+    expect(hasAutoReloaded(NOW)).toBe(true);
+    expect(hasAutoReloaded(NOW + RELOAD_WINDOW_MS)).toBe(true);
+  });
+
+  it("hasAutoReloaded is false again once the window has elapsed (a later deploy recovers)", () => {
+    markAutoReloaded(NOW);
+    // Strictly older than the window → a new deploy's mismatch may reload again.
+    expect(hasAutoReloaded(NOW + RELOAD_WINDOW_MS + 1)).toBe(false);
+  });
+
+  it("hasAutoReloaded returns true when reading storage throws (fail toward not reloading)", () => {
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => {
+        throw new Error("storage disabled");
+      },
+      setItem: () => {
+        throw new Error("storage disabled");
+      },
+    });
+    try {
+      expect(hasAutoReloaded()).toBe(true);
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+
+  it("hasAutoReloaded treats an unparseable stored timestamp as never-reloaded", () => {
+    sessionStorage.setItem(RELOAD_AT_KEY, "not-a-number");
+    expect(hasAutoReloaded(NOW)).toBe(false);
+  });
+
+  it("markAutoReloaded returns false when writing storage throws", () => {
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => null,
+      setItem: () => {
+        throw new Error("storage disabled");
+      },
+    });
+    try {
+      expect(markAutoReloaded()).toBe(false);
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+
+  it("records and then takes a breadcrumb once (cleared on read)", () => {
+    recordReloadBreadcrumb({
+      path: "proactive",
+      serverVersion: "test-B",
+      clientVersion: "test-A",
+    });
+    const crumb = takeReloadBreadcrumb();
+    expect(crumb).toMatchObject({
+      path: "proactive",
+      serverVersion: "test-B",
+      clientVersion: "test-A",
+    });
+    expect(typeof crumb?.at).toBe("number");
+    // Cleared on read → a second take returns null.
+    expect(takeReloadBreadcrumb()).toBeNull();
+  });
+
+  it("takeReloadBreadcrumb returns null when nothing was recorded", () => {
+    expect(takeReloadBreadcrumb()).toBeNull();
+  });
+
+  it("recordReloadBreadcrumb swallows a storage-write error (diagnostics only)", () => {
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => null,
+      setItem: () => {
+        throw new Error("storage disabled");
+      },
+      removeItem: () => {},
+    });
+    try {
+      expect(() =>
+        recordReloadBreadcrumb({ path: "chunk-boundary" }),
+      ).not.toThrow();
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+});
+
+// The pure window gate replaces the old one-shot flag: it must permit recovery
+// across several deploys in one tab (each > window apart) while still stopping an
+// infinite reload loop when a lazy chunk is permanently broken (a second failure
+// < window). Moved here from the chunk-load boundary now that it is the shared
+// guard both paths route through.
+describe("shouldAutoReload", () => {
+  const WINDOW = RELOAD_WINDOW_MS;
+
+  it("allows a reload when we have never auto-reloaded", () => {
+    expect(shouldAutoReload(NOW, null, WINDOW)).toBe(true);
+  });
+
+  it("allows a reload when the last one was 6 minutes ago (outside the window)", () => {
+    expect(shouldAutoReload(NOW, NOW - 6 * 60 * 1000, WINDOW)).toBe(true);
+  });
+
+  it("blocks a reload when the last one was 1 minute ago (inside the window)", () => {
+    expect(shouldAutoReload(NOW, NOW - 1 * 60 * 1000, WINDOW)).toBe(false);
+  });
+
+  it("blocks a reload exactly at the window boundary (not strictly older)", () => {
+    expect(shouldAutoReload(NOW, NOW - WINDOW, WINDOW)).toBe(false);
+  });
+
+  it("allows a reload when the stored timestamp is unparseable (NaN)", () => {
+    expect(shouldAutoReload(NOW, NaN, WINDOW)).toBe(true);
+  });
+});

apps/client/src/lib/reload-guard.ts

@@ -0,0 +1,121 @@
+// Shared, window-based auto-reload budget.
+//
+// Both auto-reload paths — the reactive chunk-load-error-boundary (recovers
+// AFTER a stale lazy chunk 404s) and the proactive version-coherence feature
+// (reloads BEFORE the tab hits a stale chunk) — go through these functions so
+// they share ONE window-scoped reload budget: at most a single automatic
+// reload per RELOAD_WINDOW_MS across BOTH paths. A window (rather than a
+// permanent one-shot flag) lets a SECOND deploy in the same tab's lifetime
+// recover too, while a permanent skew, node oscillation, or a genuinely-missing
+// chunk still degrades to a manual banner/UI after the first reload instead of
+// looping. When sessionStorage is unavailable every mismatch degrades to the
+// manual UI — no unguarded reload.
+
+// sessionStorage key holding the epoch-ms timestamp of the last automatic reload
+// (shared by both paths).
+const RELOAD_AT_KEY = "chunk-reload-at";
+
+// Allow at most one automatic reload per this window. A stale-deploy 404 is cured
+// by a single reload, so anything inside the window is treated as a reload loop
+// (permanently-broken chunk / permanent skew) and falls through to the manual UI.
+export const RELOAD_WINDOW_MS = 5 * 60 * 1000;
+
+/**
+ * Pure window decision, unit-tested in isolation: auto-reload only if we have
+ * never auto-reloaded (lastReloadAt null/NaN) or the last one was strictly older
+ * than the window. Anything inside the window is suppressed to break an infinite
+ * reload loop.
+ */
+export function shouldAutoReload(
+  now: number,
+  lastReloadAt: number | null,
+  windowMs: number,
+): boolean {
+  if (lastReloadAt === null || Number.isNaN(lastReloadAt)) return true;
+  return now - lastReloadAt > windowMs;
+}
+
+/**
+ * Has an automatic reload already happened within the current window (so the
+ * shared budget is spent right now)? Both paths check this before reloading; a
+ * `true` return means fall through to the manual banner/UI instead of reloading.
+ *
+ * A storage read error (private mode / disabled) is reported as `true` so the
+ * caller fails toward NOT reloading — an unguarded loop is worse than a stale
+ * tab the user can reload manually. Note a window (not a permanent flag): once
+ * the window elapses a later deploy's mismatch is allowed to reload again.
+ */
+export function hasAutoReloaded(now: number = Date.now()): boolean {
+  try {
+    const raw = sessionStorage.getItem(RELOAD_AT_KEY);
+    const lastReloadAt = raw === null ? null : Number.parseInt(raw, 10);
+    return !shouldAutoReload(now, lastReloadAt, RELOAD_WINDOW_MS);
+  } catch {
+    return true;
+  }
+}
+
+/**
+ * Stamp the shared window as consumed now — record that an automatic reload is
+ * being performed within the current RELOAD_WINDOW_MS window.
+ *
+ * Returns whether the write succeeded. A `false` return (storage unavailable)
+ * means the caller MUST NOT reload — otherwise the stamp would never stick and
+ * the reload could loop.
+ */
+export function markAutoReloaded(now: number = Date.now()): boolean {
+  try {
+    sessionStorage.setItem(RELOAD_AT_KEY, String(now));
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+// Diagnostic breadcrumb for an automatic reload. Written right before
+// window.location.reload() (which clears the console) and read back on the next
+// page load, so a "the tab reloaded itself / it's looping" field report is
+// diagnosable: which path fired (proactive version-coherence vs the reactive
+// chunk-load boundary) and which version pair triggered it. sessionStorage
+// survives a same-tab reload, unlike the console.
+const RELOAD_BREADCRUMB_KEY = "reload-breadcrumb";
+
+export type ReloadBreadcrumb = {
+  path: "proactive" | "chunk-boundary";
+  serverVersion?: string;
+  clientVersion?: string;
+  at: number;
+};
+
+/**
+ * Persist a best-effort breadcrumb just before an automatic reload. Failures
+ * (storage unavailable) are swallowed — this is diagnostics only and must never
+ * block or alter the reload decision.
+ */
+export function recordReloadBreadcrumb(
+  entry: Omit<ReloadBreadcrumb, "at">,
+): void {
+  try {
+    sessionStorage.setItem(
+      RELOAD_BREADCRUMB_KEY,
+      JSON.stringify({ ...entry, at: Date.now() }),
+    );
+  } catch {
+    // best-effort diagnostics only
+  }
+}
+
+/**
+ * Read and clear the breadcrumb left by an auto-reload in the previous page
+ * load. Cleared on read so it surfaces exactly once per reload.
+ */
+export function takeReloadBreadcrumb(): ReloadBreadcrumb | null {
+  try {
+    const raw = sessionStorage.getItem(RELOAD_BREADCRUMB_KEY);
+    if (!raw) return null;
+    sessionStorage.removeItem(RELOAD_BREADCRUMB_KEY);
+    return JSON.parse(raw) as ReloadBreadcrumb;
+  } catch {
+    return null;
+  }
+}

apps/client/src/lib/telemetry/route-template.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from "vitest";
-import { templateRoute } from "./route-template";
+import { templateRoute, KNOWN_ROUTE_TEMPLATES } from "./route-template";
 
 describe("templateRoute", () => {
   it("templates a space page path (never leaks slugs)", () => {
@@ -32,4 +32,30 @@ describe("templateRoute", () => {
     expect(templateRoute("/weird/unknown/thing")).toBe("other");
     expect(templateRoute("/s/team/p/slug/extra/segments")).toBe("other");
   });
+
+  // The server's /api/telemetry/vitals mirror (ALLOWED_ROUTE_TEMPLATES) drops any
+  // route outside KNOWN_ROUTE_TEMPLATES, so templateRoute must NEVER emit a label
+  // that is not in that dictionary — otherwise legit client metrics get dropped.
+  it("only ever emits labels contained in KNOWN_ROUTE_TEMPLATES (#495)", () => {
+    const samples = [
+      "/",
+      "/home",
+      "/settings/members",
+      "/settings/groups/g-1",
+      "/s/team",
+      "/s/team/trash",
+      "/s/team/p/slug",
+      "/p/slug",
+      "/share/abc",
+      "/share/abc/p/slug",
+      "/share/p/slug",
+      "/labels/urgent",
+      "/invites/inv-1",
+      "/weird/unknown/thing", // -> "other"
+      "/deep/unmatched/x/y/z", // -> "other"
+    ];
+    for (const path of samples) {
+      expect(KNOWN_ROUTE_TEMPLATES.has(templateRoute(path))).toBe(true);
+    }
+  });
 });

apps/client/src/lib/telemetry/route-template.ts

@@ -44,6 +44,22 @@ const STATIC_ROUTES = new Set<string>([
   '/settings/sharing',
 ]);
 
+/**
+ * The COMPLETE, finite vocabulary `templateRoute` can ever emit: the two
+ * synthetic labels (`/` and `other`), the static routes, and the dynamic
+ * templates. Exported so the public `/api/telemetry/vitals` endpoint can reject
+ * any `route` outside this dictionary server-side (the endpoint is anonymous, so
+ * an un-checked `route` is a free-text write surface). The server keeps a mirror
+ * (`ALLOWED_ROUTE_TEMPLATES` in client-metrics.constants.ts) — this is the
+ * canonical source; keep them in lockstep.
+ */
+export const KNOWN_ROUTE_TEMPLATES: ReadonlySet<string> = new Set<string>([
+  '/',
+  'other',
+  ...STATIC_ROUTES,
+  ...ROUTE_PATTERNS.map((p) => p.template),
+]);
+
 export function templateRoute(pathname: string): string {
   // Normalise a trailing slash (except root).
   const path =

apps/client/src/main.tsx

@@ -3,6 +3,7 @@ import "@mantine/spotlight/styles.css";
 import "@mantine/notifications/styles.css";
 import '@mantine/dates/styles.css';
 import "@/styles/a11y-overrides.css";
+import "@/styles/notification-overrides.css";
 
 import ReactDOM from "react-dom/client";
 import App from "./App.tsx";
@@ -47,7 +48,15 @@ function renderApp() {
       <MantineProvider theme={theme} cssVariablesResolver={mantineCssResolver}>
         <ModalsProvider>
           <QueryClientProvider client={queryClient}>
-            <Notifications position="bottom-center" limit={3} zIndex={10000} />
+            {/* top-center: toasts sit in the top of the viewport, in the line
+                of sight, and no longer cover centered content (e.g. "Load
+                more"). The below-chrome vertical offset is applied via a
+                position-scoped CSS rule in notification-overrides.css (NOT an
+                inline `style`): Mantine renders all six position containers at
+                once and an inline root style would land on every one, giving the
+                bottom-* containers both top+bottom → full-viewport transparent
+                overlays that swallow clicks. */}
+            <Notifications position="top-center" limit={3} zIndex={10000} />
             <HelmetProvider>
               {/* Root boundary above every lazy route's Suspense: a stale-chunk
                   404 after a deploy is caught and recovered here instead of

apps/client/src/styles/notification-overrides.css

@@ -0,0 +1,64 @@
+/*
+ * Toast (Mantine Notification) visibility overrides.
+ * Mantine renders colorless toasts on --mantine-color-body (== the page
+ * background: white in light mode) with a faint shadow, so on white pages the
+ * card has no visible edge. These rules give every toast a type-tinted
+ * background, a WCAG-checked border and a stronger shadow so it separates from
+ * the page. The [data-mantine-color-scheme] + static-class selector (0,2,0)
+ * beats Mantine's own (0,1,0) rules regardless of stylesheet order (Mantine's
+ * bg/border rules wrap the scheme attribute in :where(), so they stay (0,1,0)).
+ * --notification-color is defined on the same element (defaults to primary,
+ * set per `color` prop), so tint/border follow the toast type. This also covers
+ * the loading/import toast (no accent bar, since the spinner takes the icon
+ * slot): its visibility comes from tone + border + shadow + the colored spinner.
+ */
+
+/*
+ * Push the top-anchored toast containers below the top chrome (fixed 45px
+ * header + optional 45px format toolbar + ~6px gap) so a toast (z-index 10000)
+ * neither covers nor intercepts clicks on the header/toolbar (both z-index 99).
+ *
+ * Scoped to [data-position^='top'] on purpose. Mantine renders ALL SIX position
+ * containers simultaneously (`position` only routes toasts into one via the
+ * store); the root `style` prop would be applied to every one of them by
+ * getStyles("root"). A blanket `top` would land on the bottom-* containers too
+ * (which carry `bottom:16px`) → position:fixed + both edges + height:auto makes
+ * them stretch the full viewport height, and the container root has neither
+ * pointer-events:none nor a background, so those transparent z-10000 overlays
+ * would swallow clicks across the whole page. Restricting to top-* leaves the
+ * bottom containers at height:0.
+ *
+ * Specificity: `.mantine-Notifications-root[data-position^='top']` is (0,2,0)
+ * (class + attribute) and beats Mantine's own top rule
+ * `.m_b37d9ac7:where([data-position='top-center']){top:16px}` which is (0,1,0)
+ * (the :where() contributes 0), regardless of stylesheet order.
+ */
+.mantine-Notifications-root[data-position^='top'] {
+  top: 96px;
+}
+
+[data-mantine-color-scheme='light'] .mantine-Notification-root {
+  /* ~10% type color over white: clearly off-white, text contrast preserved */
+  background-color: color-mix(in srgb, var(--notification-color) 10%, var(--mantine-color-white));
+  /* Border must clear WCAG 3:1 non-text contrast on white. The repo rejects
+     gray-4 for this (a11y-overrides.css); gray-6 base (~3.32:1) darkened by the
+     type color stays >= 3:1. */
+  border: 1px solid color-mix(in srgb, var(--notification-color) 45%, var(--mantine-color-gray-6));
+  box-shadow: var(--mantine-shadow-xl);
+}
+
+[data-mantine-color-scheme='dark'] .mantine-Notification-root {
+  /* Dark page (dark-7/8) vs toast (dark-6) already separate a little; border +
+     shadow carry the type cue here (a 7% dark tint was near-invisible). */
+  background-color: color-mix(in srgb, var(--notification-color) 14%, var(--mantine-color-dark-6));
+  border: 1px solid color-mix(in srgb, var(--notification-color) 45%, var(--mantine-color-dark-3));
+  box-shadow: var(--mantine-shadow-xl);
+}
+
+/* Mantine's message-with-title color is gray-6 (#868e96, already only ~3.32:1
+   on white — below AA 4.5:1); the new tint pushes it lower. Bump to gray-7 to
+   keep multi-line colored toasts readable, consistent with the repo's existing
+   WCAG tuning (theme.ts already bumps this same gray-6 up elsewhere). */
+[data-mantine-color-scheme='light'] .mantine-Notification-description[data-with-title] {
+  color: var(--mantine-color-gray-7);
+}

apps/client/vite.config.ts

@@ -1,7 +1,8 @@
-import { defineConfig, loadEnv } from "vite";
+import { defineConfig, loadEnv, type Plugin } from "vite";
 import react from "@vitejs/plugin-react";
 import { compression } from "vite-plugin-compression2";
 import * as path from "path";
+import * as fs from "node:fs";
 import { execSync } from "node:child_process";
 
 const envPath = path.resolve(process.cwd(), "..", "..");
@@ -24,7 +25,32 @@ function resolveAppVersion(cwd: string): string {
   }
 }
 
+// Emit <outDir>/version.json = { "version": appVersion } so the server can read
+// the exact same build id the bundle was compiled with. The value is the SAME
+// `appVersion` fed into `define.APP_VERSION`, so version.json and the baked-in
+// global are identical by construction — the single source of truth (no
+// runtime-env second copy that could drift and cause a false version mismatch).
+function versionJsonPlugin(version: string): Plugin {
+  let outDir = "dist";
+  return {
+    name: "emit-version-json",
+    apply: "build",
+    configResolved(config) {
+      outDir = config.build.outDir;
+    },
+    writeBundle() {
+      const root = path.resolve(process.cwd(), outDir);
+      fs.mkdirSync(root, { recursive: true });
+      fs.writeFileSync(
+        path.join(root, "version.json"),
+        JSON.stringify({ version }),
+      );
+    },
+  };
+}
+
 export default defineConfig(({ mode }) => {
+  const appVersion = resolveAppVersion(envPath);
   const {
     APP_URL,
     FILE_UPLOAD_SIZE_LIMIT,
@@ -52,10 +78,11 @@ export default defineConfig(({ mode }) => {
         POSTHOG_HOST,
         POSTHOG_KEY,
       },
-      APP_VERSION: JSON.stringify(resolveAppVersion(envPath)),
+      APP_VERSION: JSON.stringify(appVersion),
     },
     plugins: [
       react(),
+      versionJsonPlugin(appVersion),
       // Emit .br and .gz next to every built asset so the server can serve the
       // precompressed copy (see @fastify/static preCompressed in static.module.ts).
       compression({