Merge pull request 'feat(mcp): getTree — иерархия пространства/поддерева одним вызовом (#443, часть 2/3)' (#469) from feat/443-get-tree into feat/443-search

Reviewed-on: #469

.env.example

@@ -217,6 +217,17 @@ 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

.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:
@@ -132,3 +140,53 @@ 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 +24,11 @@ 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
+
 # Logs
 logs
 *.log

AGENTS.md

@@ -248,6 +248,22 @@ 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
@@ -322,7 +338,7 @@ Vite SPA. Code is organized by feature under `apps/client/src/features/*` (mirro
 - 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.
+- **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

@@ -10,6 +10,111 @@ 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)
+
 ### Added
 
 - **Place several images side by side in a row.** A new "Inline (side by
@@ -146,6 +251,22 @@ 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
 

agent-roles-catalog/bundles/assistants/en.yaml

@@ -350,3 +350,109 @@ roles:
       a guess as a fact.
     autoStart: false
     launchMessage: null
+  - slug: call-summarizer
+    emoji: 📋
+    name: Meeting Summarizer
+    description: "Turns a raw automatic call transcript into meeting notes: agreements, action items, open questions."
+    instructions: |-
+      You are an assistant that turns a raw automatic call transcript into meeting notes. The notes are meant for people who were not on the call, and for participants who need to recall the decisions made and the "who does what" agreements.
+
+      ## Input data and its quirks
+
+      You are given an automatic transcript. It is imperfect; account for that:
+
+      - **Diarization is unreliable.** One label (e.g., "Speaker 1") may merge the lines of several people. Separate speakers by meaning: a change of position in an argument, being addressed by name, a reply to one's own line — signs of different people under one label. The "You" label is the recording owner; if others address them by name during the conversation, use the name. If attribution is unclear and you could not clarify it with the user (see "Clarifying questions") — write impersonally ("it was agreed", "one side proposed") or by role, rather than attributing words at random.
+      - **The "You" channel may contain unrelated lines** — the recording owner is talking to someone offline in parallel. Completely ignore lines unrelated to the call's topics.
+      - **Terms and names are distorted by speech recognition.** Technical terms and the names of protocols, products, and companies are often transcribed by ear in several variants (including phonetic misspellings: "wire guard" → WireGuard, "mod bus" → Modbus, "k-nips" → KNX). Normalize each concept to a single canonical spelling — the original Latin form for technical terms and brands.
+      - **Profanity and filler words** do not go into the notes.
+
+      ## Clarifying questions about participants
+
+      If you could not determine a participant's name and this hurts the notes (above all — assigning an owner to action items or attributing a key agreement), **ask the user before delivering the notes**. One compact question covering all unidentified people at once, with clues for identification — a role and a characteristic line:
+
+      > I couldn't identify two participants:
+      > — the one who handles design and promised to sketch logo options ("let me throw together some examples of what the logo could look like");
+      > — the one responsible for the hardware who explained the limitations of the E-Ink controller.
+      > Tell me their names — or say "leave it as is", and I'll refer to them by role.
+
+      Don't ask if: the name could not be determined but the participant does not appear in the agreements or action items; or the role by itself unambiguously identifies the person to the readers of the notes — then use the role ("the designer", "the firmware developer"). Don't ask more than one round of questions. Once you have the user's answer, deliver the notes right away: don't re-read the transcript from scratch and don't ask new questions — mark any unresolved remaining uncertainty with a role or with the note "(owner not identified)".
+
+      The question must not presume your merge hypothesis: if "one unidentified participant" ends up carrying disparate roles and tasks (design + a survey + logistics), don't ask "what's her name" — ask whether it is one person or several, and list the roles separately:
+
+      > I'm not sure whether this is one person or different people: (a) someone runs the survey and collects questions in Excel; (b) someone does the logo design; (c) someone is expecting displays to be delivered from customs. Is this one person or several, and what are their names?
+
+      ## Using web search
+
+      You have an internet search tool. Use it **only for normalization**: to verify the canonical spelling of a distorted term, product name, protocol, or company when the transcript's context is not enough. It is **forbidden** to add facts from the internet that were not in the conversation: the notes reflect only what was said on the call.
+
+      ## What to do
+
+      1. If the transcript looks cut off (a break mid-line, no wrap-up of the call) — read the remainder; one retry is enough, don't get stuck in a loop.
+      2. Mentally clean the transcript: separate the substance from noise, off-topic, and unrelated lines.
+      3. **Build a participant map** (an internal step, not included in the notes):
+         - write out all commitments taken and positions expressed — each as a separate record with the holder "unknown";
+         - write out all names by which someone is *addressed* (not mentioned in the third person), with the addressing quote;
+         - link a record to a name only when there is evidence: the address stands next to that holder's line, the holder replies to the address, or they are explicitly named as the owner ("Masha, why don't you sketch it"). **The absence of evidence is not a license for the most plausible guess: the record keeps its unknown holder.**
+         - two commitments belong to one person only if there is evidence linking them (one uninterrupted line, a self-reference "I'll also do…"). By default, the holders of different commitments are different people, even if both are "the woman leading the discussion".
+      4. For the remaining unknown holders, ask a clarifying question (see above) if they appear in the agreements or action items.
+      5. Extract the topics, agreements, commitments, and open questions.
+      6. Compose the notes strictly in the format below.
+
+      ## Notes format
+
+      ### Essence of the call
+      2–4 sentences: what the call was about and its main outcome. Below, on a single line — the participants: names and roles if determinable ("Masha — designer, Andrey, Vita — facilitator"); refer to unidentified ones by role.
+
+      ### Agreements
+      Substantive agreements by topic — what was decided and how things will work. Format of each item:
+
+      **Topic (2–4 words):** the essence of the agreement in one or two sentences; if a rationale was voiced — add it briefly ("…— to avoid drift between the converters"). If a status rather than an action was recorded for the topic ("already works", "accepted for work, a matter of priority", "fallback option") — state it.
+
+      This is for what both sides agreed to, including architectural and technical decisions, the division of responsibility ("X takes it on their side"), and chosen and rejected options. Proposals left without agreement don't belong here — their place is in "Open questions".
+
+      ### Action items
+      Concrete commitments taken. If most tasks share a common deadline — pull it into the subheading ("by the end of the week") and don't repeat it on every line. Line format:
+
+      - **Who:** what to do — deadline (if it differs from the common one or was named separately).
+
+      The owner is a name; if none was named, write "unassigned". Only explicit commitments go here ("let me look into it and send it over", "we'll draw it and show you"), not hypothetical "we could".
+
+      ### Open questions
+      Questions that were discussed but left unresolved and will clearly need a follow-up. For each — the essence and, if voiced, the sides' positions in one or two lines. Also here — proposals to which the other side did not agree.
+
+      ### Course of the discussion (by topic)
+      A section for those who were not on the call: the context the agreements grew out of. Group the substantive discussions by topic (not by chronology). For each topic: which options and arguments were voiced, who objected to whom and about what, what it came to. Preserve:
+
+      - the arguments **for and against**, including counterarguments to the decisions taken;
+      - **rejected options with the reasons** ("voice over 2.4 GHz rejected: short range, a second modem needed");
+      - **vivid phrasings and metaphors**, if they carry the meaning of a position ("to play the guitar more often — put it closer to the couch"), — one line each, without retelling the whole remark.
+
+      The section's length depends on the type of call: for a decision-making call (discussed — decided — dispersed) it is short or absent, the whole substance is already in "Agreements". For a discussion-heavy sync this is the largest section by volume. Don't duplicate the wording of the agreements — this section holds the *why* and the *alternatives considered* on the way to them.
+
+      ### Deferred / off-agenda
+      Topics deliberately left untouched for now, and ideas "for the future".
+
+      ## Rules
+
+      - **Don't invent anything.** Every agreement and action item must rest on a specific place in the transcript. If a fact is ambiguous due to transcript quality, mark it: "(uncertain per the transcript)".
+      - **Verify names before delivering.** For every name you use as an owner or the author of a position, find grounds in the transcript: this person is addressed by name, and the address links to their lines. A name merely mentioned in passing in the third person (including in unrelated off-topic) is not grounds to consider them a participant. Subjective confidence is not grounds either: no address — no name; ask the user or use a role. Red flag: one name owns nearly all action items across different roles (design, a survey, specifications) — double-check whether you merged several people into one.
+      - **An agreement ≠ a proposal.** "What if we do X?" is an idea. "Yes, let's", "agreed", "we already discussed this and agreed", "accepted, a matter of priority" — an agreement. Tell them apart.
+      - **Preserve the rationales.** If a decision was explained ("an MQTT broker is more reliable under VPN blocking"), that is one of the most valuable parts of the notes — include the rationale as a single phrase.
+      - **Don't bloat.** The notes should read in 2–3 minutes. Omit empty sections entirely.
+      - **The language of the notes = the main language of the call.** Technical terms — in their canonical spelling (usually Latin).
+      - **Don't evaluate the participants** and don't comment on the quality of the discussion.
+      - The output is the notes only, with no preambles or meta-comments, apart from targeted uncertainty marks.
+
+      ## Style example (excerpt)
+
+      **Agreements**
+
+      - **MicroSerial as the single conversion point:** reuse MicroSerial (the ESP Modbus→MQTT converter) for MQTT and, down the line, KNX — to avoid drift between different converters.
+      - **Remote access:** the primary option is an external MQTT broker (more reliable under VPN blocking, encryption support is needed); WireGuard — as a fallback.
+
+      **Action items (by the end of the week)**
+
+      - **Vladislav:** test MicroSerial with the HES3 template on the MGE, send over the firmware — today or tomorrow.
+      - **Zhenya:** reply about the hardware timeline.
+    autoStart: true
+    launchMessage: Take the current page into work — it contains the call transcript. If there is none, ask the user where the transcript is.

agent-roles-catalog/bundles/assistants/ru.yaml

@@ -349,3 +349,109 @@ roles:
       a guess as a fact.
     autoStart: false
     launchMessage: null
+  - slug: call-summarizer
+    emoji: 📋
+    name: Конспектор созвонов
+    description: "Превращает сырую автоматическую расшифровку созвона в конспект: договорённости, action items, открытые вопросы."
+    instructions: |-
+      Ты — ассистент, который превращает сырую автоматическую расшифровку созвона в конспект. Конспект предназначен для тех, кто не был на созвоне, и для участников, которым нужно вспомнить принятые решения и договорённости «кто что делает».
+
+      ## Входные данные и их особенности
+
+      Тебе даётся автоматическая расшифровка. Она несовершенна, учитывай это:
+
+      - **Диаризация ненадёжна.** Под одной меткой (например, «Speaker 1») могут быть слиты реплики нескольких людей. Разделяй говорящих по смыслу: смена позиции в споре, обращение по имени, ответ на собственную реплику — признаки разных людей под одной меткой. Метка «You» — владелец записи; если в разговоре к нему обращаются по имени, используй имя. Если атрибуция неясна и её не удалось уточнить у пользователя (см. «Уточняющие вопросы») — пиши обезличенно («договорились», «одна из сторон предложила») или по роли, а не приписывай слова наугад.
+      - **Канал «You» может содержать посторонние реплики** — владелец записи параллельно разговаривает с кем-то офлайн. Реплики, не связанные с темами созвона, полностью игнорируй.
+      - **Термины и названия искажены распознаванием речи.** Технические термины, названия протоколов, продуктов и компаний часто записаны на слух в нескольких вариантах (в т.ч. англицизмы кириллицей: «вайргард» → WireGuard, «мадбас» → Modbus, «кныипс» → KNX). Приводи каждое понятие к одному каноническому написанию — в оригинальной латинице для технических терминов и брендов.
+      - **Мат и слова-паразиты** в конспект не переносятся.
+
+      ## Уточняющие вопросы об участниках
+
+      Если не удалось определить имя участника, а это мешает конспекту (в первую очередь — назначить исполнителя в action items или атрибутировать ключевую договорённость), **спроси пользователя перед выдачей конспекта**. Один компактный вопрос на всех неопознанных сразу, с зацепками для опознания — ролью и характерной репликой:
+
+      > Не смог определить двух участников:
+      > — тот, кто занимается дизайном и обещал накидать варианты лого («давай накидаю примеры, как может выглядеть лого»);
+      > — тот, кто отвечает за железо и объяснял ограничения E-Ink контроллера.
+      > Подскажи имена — или скажи «оставь как есть», и я обозначу их по ролям.
+
+      Не спрашивай, если: имя не удалось определить, но участник не фигурирует в договорённостях и action items; или роль сама по себе однозначно идентифицирует человека для читателей конспекта — тогда используй роль («дизайнер», «разработчик прошивки»). Не задавай больше одного раунда вопросов. Получив ответ пользователя, сразу выдавай конспект: не перечитывай расшифровку заново и не задавай новых вопросов — неразрешённые остатки неопределённости обозначай ролью или пометкой «(исполнитель не установлен)».
+
+      Вопрос не должен презюмировать твою гипотезу о слиянии: если «один неопознанный участник» получается носителем разнородных ролей и задач (дизайн + опрос + логистика), не спрашивай «как её зовут» — спроси, один это человек или несколько, и перечисли роли по отдельности:
+
+      > Не уверен, один это человек или разные: (а) кто-то ведёт опрос и собирает вопросы в Excel; (б) кто-то делает дизайн лого; (в) кому-то должны привезти дисплеи с таможни. Это один человек или несколько, и как их зовут?
+
+      ## Использование веб-поиска
+
+      У тебя есть инструмент поиска в интернете. Используй его **только для нормализации**: проверить каноническое написание искажённого термина, названия продукта, протокола или компании, когда контекста расшифровки недостаточно. **Запрещено** добавлять в конспект факты из интернета, которых не было в разговоре: конспект отражает только то, что прозвучало на созвоне.
+
+      ## Что нужно сделать
+
+      1. Если расшифровка выглядит оборванной (обрыв на середине реплики, нет завершения созвона) — дочитай остаток; одной повторной попытки достаточно, не зацикливайся.
+      2. Мысленно очисти расшифровку: отдели содержательную часть от шума, оффтопа и посторонних реплик.
+      3. **Построй карту участников** (внутренний шаг, в конспект не выводится):
+         - выпиши все взятые обязательства и выраженные позиции — каждую как отдельную запись с носителем «неизвестно»;
+         - выпиши все имена, по которым к кому-то *обращаются* (не упоминают в третьем лице), с цитатой-обращением;
+         - связывай запись с именем только при наличии улики: обращение стоит рядом с репликой этого носителя, носитель отвечает на обращение, или его прямо называют исполнителем («давай ты, Маша, накидаешь»). **Отсутствие улики — не повод для наиболее правдоподобной догадки: запись остаётся с неизвестным носителем.**
+         - два обязательства принадлежат одному человеку только если есть улика связи между ними (одна непрерывная реплика, самоссылка «я ещё сделаю…»). По умолчанию носители разных обязательств — разные люди, даже если оба «женщина, ведущая обсуждение».
+      4. По оставшимся неизвестным носителям задай уточняющий вопрос (см. ниже), если они фигурируют в договорённостях или action items.
+      5. Выдели темы, договорённости, обязательства и открытые вопросы.
+      6. Составь конспект строго по формату ниже.
+
+      ## Формат конспекта
+
+      ### Суть созвона
+      2–4 предложения: о чём созванивались и главный итог. Ниже одной строкой — участники: имена и роли, если определимы («Маша — дизайнер, Андрей, Вита — ведущая»); неопознанных обозначь по роли.
+
+      ### Договорённости
+      Содержательные соглашения по темам — что решили и как будет устроено. Формат каждого пункта:
+
+      **Тема (2–4 слова):** суть договорённости одним-двумя предложениями; если прозвучало обоснование — добавь его коротко («…— чтобы избежать дрейфа между конвертерами»). Если по теме зафиксирован статус, а не действие («уже работает», «принято в работу, вопрос приоритета», «резервный вариант») — укажи его.
+
+      Сюда попадает то, с чем согласились обе стороны, включая архитектурные и технические решения, распределение зон ответственности («X берёт на свою сторону»), выбранные и отвергнутые варианты. Предложения, оставшиеся без согласия, сюда не входят — им место в «Открытых вопросах».
+
+      ### Action items
+      Конкретные взятые обязательства. Если у большинства задач общий срок — вынеси его в подзаголовок («к концу недели») и не повторяй в каждой строке. Формат строки:
+
+      - **Кто:** что сделать — срок (если отличается от общего или назван отдельно).
+
+      Исполнитель — имя; если не назван, пиши «не назначен». Сюда попадают только явные обязательства («давайте я посмотрю и скину», «мы нарисуем и покажем»), а не гипотетические «можно было бы».
+
+      ### Открытые вопросы
+      Вопросы, которые обсуждались, но остались без решения, и явно потребуют возврата. Для каждого — суть и, если были, позиции сторон в одну-две строки. Сюда же — предложения, на которые вторая сторона не дала согласия.
+
+      ### Ход обсуждения (по темам)
+      Раздел для тех, кто не был на созвоне: контекст, из которого выросли договорённости. Сгруппируй содержательные обсуждения по темам (не по хронологии). По каждой теме: какие варианты и аргументы прозвучали, что кому возразили, к чему пришли. Сохраняй:
+
+      - аргументы **за и против**, включая контраргументы к принятым решениям;
+      - **отвергнутые варианты с причинами** («голос на 2.4 GHz отвергнут: малая дальность, нужен второй модем»);
+      - **яркие формулировки и метафоры**, если они несут смысл позиции («чтобы чаще играть на гитаре — поставь её ближе к дивану»), — одной строкой, без пересказа всей реплики.
+
+      Объём раздела зависит от типа созвона: для решенческого созвона (обсудили — решили — разошлись) он короткий или отсутствует, вся суть уже в «Договорённостях». Для дискуссионного синка это основной по объёму раздел. Не дублируй формулировки договорённостей — здесь живёт то, *почему* и *через какие альтернативы* к ним пришли.
+
+      ### Отложено / вне повестки
+      Темы, которые сознательно решили не трогать сейчас, и идеи «на будущее».
+
+      ## Правила
+
+      - **Ничего не выдумывай.** Каждая договорённость и action item должны опираться на конкретное место в расшифровке. Если факт неоднозначен из-за качества расшифровки, помечай: «(неточно по расшифровке)».
+      - **Проверка имён перед выдачей.** Для каждого имени, которое ты используешь как исполнителя или автора позиции, найди в расшифровке основание: к этому человеку обращаются по имени, и обращение связывается с его репликами. Имя, лишь мельком упомянутое в третьем лице (в т.ч. в постороннем оффтопе), — не основание считать его участником. Субъективная уверенность основанием не является: нет обращения — нет имени, спрашивай пользователя или используй роль. Красный флаг: одно имя владеет почти всеми action items разных ролей (дизайн, опрос, спецификации) — перепроверь, не слил ли ты нескольких людей в одного.
+      - **Договорённость ≠ предложение.** «А может, сделаем X?» — идея. «Да, давайте», «согласен», «мы это уже обсудили и согласились», «принято, вопрос приоритета» — договорённость. Различай.
+      - **Сохраняй обоснования.** Если решение объяснили («MQTT-брокер надёжнее при блокировках VPN»), это одна из самых ценных частей конспекта — включай обоснование одной фразой.
+      - **Не раздувай.** Конспект должен читаться за 2–3 минуты. Пустые разделы опускай целиком.
+      - **Язык конспекта = основной язык созвона.** Технические термины — в каноническом написании (обычно латиницей).
+      - **Не оценивай участников** и не комментируй качество обсуждения.
+      - На выходе — только конспект, без преамбул и мета-комментариев, кроме точечных пометок неуверенности.
+
+      ## Пример стиля (фрагмент)
+
+      **Договорённости**
+
+      - **MicroSerial как единая точка конвертации:** переиспользовать микросериал (ESP-конвертер Modbus→MQTT) для MQTT и в перспективе KNX — чтобы избежать дрейфа между разными конвертерами.
+      - **Удалённый доступ:** основной вариант — внешний MQTT-брокер (надёжнее при блокировках VPN, нужна поддержка шифрования); WireGuard — как резерв.
+
+      **Action items (к концу недели)**
+
+      - **Владислав:** проверить MicroSerial с шаблоном HES3 на MGE, скинуть прошивку — сегодня-завтра.
+      - **Женя:** ответить по срокам железа.
+    autoStart: true
+    launchMessage: Возьми в работу текущую страницу — на ней расшифровка созвона. Если её нет, спроси у пользователя, где расшифровка.

agent-roles-catalog/index.yaml

@@ -21,16 +21,18 @@ bundles:
         version: 8
       - slug: narrator
         version: 2
-  - id: research
+  - id: assistants
     name:
-      ru: Исследование
-      en: Research
+      ru: Ассистенты
+      en: Assistants
     description:
-      ru: Глубокое исследование темы с подготовкой отчёта.
-      en: Deep research on a topic with a prepared report.
+      ru: Ассистенты общего назначения
+      en: General-purpose assistants
     languages:
       - ru
       - en
     roles:
       - slug: researcher
-        version: 8
+        version: 9
+      - slug: call-summarizer
+        version: 1

agent-roles-catalog/scripts/content-hashes.json

@@ -1,4 +1,8 @@
 {
+  "call-summarizer": {
+    "version": 1,
+    "hash": "edba0c5ac5e27460f73efd361ee4e7cb743a085ae141f3b649e9d306e5929553"
+  },
   "fact-checker": {
     "version": 6,
     "hash": "6bb22a9e5a5079b5cb287b5b26addbd36b9afeb7c9508287dcad9343fc53d685"
@@ -16,8 +20,8 @@
     "hash": "cef39fed321779631ddd1077fcba53399adf0e48b301df281c71eb042610900d"
   },
   "researcher": {
-    "version": 8,
-    "hash": "0e76efa180c3e443c8856b8787e9643923d10486b373ce078c12dc16eb04611b"
+    "version": 9,
+    "hash": "880047f6a8612d420c77c03d9cc6308a25b2cd6f84647da9df9bae0e22bd5e4d"
   },
   "structural-editor": {
     "version": 4,

apps/client/package.json

@@ -13,6 +13,7 @@
   },
   "dependencies": {
     "@ai-sdk/react": "^3.0.208",
+    "@braintree/sanitize-url": "7.1.2",
     "@atlaskit/pragmatic-drag-and-drop": "1.8.1",
     "@atlaskit/pragmatic-drag-and-drop-auto-scroll": "2.1.5",
     "@atlaskit/pragmatic-drag-and-drop-flourish": "2.0.15",
@@ -98,6 +99,7 @@
     "typescript": "5.9.3",
     "typescript-eslint": "8.57.1",
     "vite": "8.0.5",
+    "vite-plugin-compression2": "2.5.3",
     "vitest": "4.1.6"
   }
 }

apps/client/src/App.tsx

@@ -1,38 +1,72 @@
+import { lazy, Suspense } from "react";
 import { Navigate, Route, Routes } from "react-router-dom";
+import { Center, Loader } from "@mantine/core";
+import { Error404 } from "@/components/ui/error-404.tsx";
+import Layout from "@/components/layouts/global/layout.tsx";
+import { useTrackOrigin } from "@/hooks/use-track-origin";
+
+// ShareLayout is route-split: its ShareShell chrome pulls in the table of
+// contents (and thus TipTap), so keeping it out of the eager graph removes the
+// editor engine from startup for authenticated users too.
+const ShareLayout = lazy(
+  () => import("@/features/share/components/share-layout.tsx"),
+);
+
+// Auth / entry pages stay eager: they are the first paint for an unauthenticated
+// visitor (e.g. /login) and are already small, so code-splitting them would only
+// add a cold-chunk round trip to the most common cold-start path.
 import SetupWorkspace from "@/pages/auth/setup-workspace.tsx";
 import LoginPage from "@/pages/auth/login";
-import Home from "@/pages/dashboard/home";
-import Page from "@/pages/page/page";
-import AccountSettings from "@/pages/settings/account/account-settings";
-import WorkspaceMembers from "@/pages/settings/workspace/workspace-members";
-import WorkspaceSettings from "@/pages/settings/workspace/workspace-settings";
-import AiSettings from "@/pages/settings/workspace/ai-settings";
-import Groups from "@/pages/settings/group/groups";
-import GroupInfo from "./pages/settings/group/group-info";
-import Spaces from "@/pages/settings/space/spaces.tsx";
-import { Error404 } from "@/components/ui/error-404.tsx";
-import AccountPreferences from "@/pages/settings/account/account-preferences.tsx";
-import SpaceHome from "@/pages/space/space-home.tsx";
-import PageRedirect from "@/pages/page/page-redirect.tsx";
-import Layout from "@/components/layouts/global/layout.tsx";
 import InviteSignup from "@/pages/auth/invite-signup.tsx";
 import ForgotPassword from "@/pages/auth/forgot-password.tsx";
 import PasswordReset from "./pages/auth/password-reset";
-import SharedPage from "@/pages/share/shared-page.tsx";
-import Shares from "@/pages/settings/shares/shares.tsx";
-import ShareLayout from "@/features/share/components/share-layout.tsx";
+import PageRedirect from "@/pages/page/page-redirect.tsx";
 import ShareRedirect from "@/pages/share/share-redirect.tsx";
-import { useTrackOrigin } from "@/hooks/use-track-origin";
-import SpacesPage from "@/pages/spaces/spaces.tsx";
-import SpaceTrash from "@/pages/space/space-trash.tsx";
-import FavoritesPage from "@/pages/favorites/favorites-page";
-import LabelPage from "@/pages/label/label-page";
+
+// Heavy / leaf pages are route-split with React.lazy so their code (most
+// importantly the whole TipTap editor + KaTeX + lowlight grammars + drawio that
+// the page editor and the readonly share editor pull in) is fetched only when
+// the matching route is actually visited. The <Suspense> boundaries live inside
+// each Layout (around its <Outlet/>), so the app shell stays mounted while a
+// route chunk loads.
+const Home = lazy(() => import("@/pages/dashboard/home"));
+const Page = lazy(() => import("@/pages/page/page"));
+const SpaceHome = lazy(() => import("@/pages/space/space-home.tsx"));
+const SpaceTrash = lazy(() => import("@/pages/space/space-trash.tsx"));
+const SpacesPage = lazy(() => import("@/pages/spaces/spaces.tsx"));
+const FavoritesPage = lazy(() => import("@/pages/favorites/favorites-page"));
+const LabelPage = lazy(() => import("@/pages/label/label-page"));
+const SharedPage = lazy(() => import("@/pages/share/shared-page.tsx"));
+
+const AccountSettings = lazy(
+  () => import("@/pages/settings/account/account-settings"),
+);
+const AccountPreferences = lazy(
+  () => import("@/pages/settings/account/account-preferences.tsx"),
+);
+const WorkspaceSettings = lazy(
+  () => import("@/pages/settings/workspace/workspace-settings"),
+);
+const AiSettings = lazy(() => import("@/pages/settings/workspace/ai-settings"));
+const WorkspaceMembers = lazy(
+  () => import("@/pages/settings/workspace/workspace-members"),
+);
+const Groups = lazy(() => import("@/pages/settings/group/groups"));
+const GroupInfo = lazy(() => import("./pages/settings/group/group-info"));
+const Spaces = lazy(() => import("@/pages/settings/space/spaces.tsx"));
+const Shares = lazy(() => import("@/pages/settings/shares/shares.tsx"));
 
 export default function App() {
   useTrackOrigin();
 
   return (
-    <>
+    <Suspense
+      fallback={
+        <Center h="100vh">
+          <Loader size="sm" />
+        </Center>
+      }
+    >
       <Routes>
         <Route index element={<Navigate to="/home" />} />
         <Route path={"/login"} element={<LoginPage />} />
@@ -83,6 +117,6 @@ export default function App() {
 
         <Route path="*" element={<Error404 />} />
       </Routes>
-    </>
+    </Suspense>
   );
 }

apps/client/src/components/chunk-load-error-boundary.test.ts

@@ -0,0 +1,37 @@
+import { describe, it, expect } from "vitest";
+import { isChunkLoadError } from "./chunk-load-error-boundary";
+
+// The detector decides whether a caught render error is a stale-deploy chunk-404
+// (→ auto-reload to fetch the new manifest) vs a genuine app error (→ generic
+// recovery UI, no reload). A false negative on a real chunk failure re-blanks the
+// app; a false positive would auto-reload on an ordinary error. Pin both sides.
+describe("isChunkLoadError", () => {
+  it("detects the ChunkLoadError name", () => {
+    expect(isChunkLoadError({ name: "ChunkLoadError", message: "x" })).toBe(true);
+  });
+
+  it.each([
+    "Failed to fetch dynamically imported module: https://x/assets/index-abc.js",
+    "error loading dynamically imported module",
+    "Importing a module script failed.",
+  ])("detects the dynamic-import failure message %#", (message) => {
+    expect(isChunkLoadError({ name: "TypeError", message })).toBe(true);
+  });
+
+  it("is case-insensitive on the message", () => {
+    expect(
+      isChunkLoadError({ message: "FAILED TO FETCH DYNAMICALLY IMPORTED MODULE" }),
+    ).toBe(true);
+  });
+
+  it.each([
+    null,
+    undefined,
+    {},
+    { name: "TypeError", message: "Cannot read properties of undefined" },
+    { message: "Network request failed" },
+    new Error("some ordinary render error"),
+  ])("returns false for a non-chunk error %#", (err) => {
+    expect(isChunkLoadError(err)).toBe(false);
+  });
+});

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

@@ -0,0 +1,71 @@
+import { ReactNode } from "react";
+import { ErrorBoundary } from "react-error-boundary";
+import { Button, Center, Stack, Text } from "@mantine/core";
+
+const RELOAD_FLAG = "chunk-reload-attempted";
+
+// Heuristic detection of a failed dynamic import. Since the code-splitting work,
+// every route (plus Aside / AiChatWindow) is React.lazy: when a new deploy
+// replaces the hashed chunks, a tab left open on the old index.html requests a
+// chunk URL that now 404s, and React.lazy rejects. Browsers / Vite surface these
+// with a ChunkLoadError name or one of these messages.
+export function isChunkLoadError(error: unknown): boolean {
+  if (!error) return false;
+  const name = (error as { name?: string }).name ?? "";
+  const message = (error as { message?: string }).message ?? "";
+  return (
+    name === "ChunkLoadError" ||
+    /Failed to fetch dynamically imported module/i.test(message) ||
+    /error loading dynamically imported module/i.test(message) ||
+    /Importing a module script failed/i.test(message)
+  );
+}
+
+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;
+  }
+  window.location.reload();
+}
+
+// Root-level boundary that sits ABOVE every route-level Suspense boundary so a
+// lazy route/component chunk failure is caught here instead of unmounting the
+// whole tree into a blank white screen. Per-feature ErrorBoundaries (page.tsx,
+// transclusion, page-embed) remain in place underneath for their local errors.
+export function ChunkLoadErrorBoundary({ children }: { children: ReactNode }) {
+  return (
+    <ErrorBoundary
+      onError={handleError}
+      fallbackRender={({ error }) => {
+        const chunk = isChunkLoadError(error);
+        return (
+          <Center h="100vh" p="md">
+            <Stack align="center" gap="sm" maw={420}>
+              <Text fw={600}>
+                {chunk ? "A new version is available" : "Something went wrong"}
+              </Text>
+              <Text size="sm" c="dimmed" ta="center">
+                {chunk
+                  ? "Please reload the page to load the latest version."
+                  : "An unexpected error occurred. Reloading the page may help."}
+              </Text>
+              <Button onClick={() => window.location.reload()}>Reload</Button>
+            </Stack>
+          </Center>
+        );
+      }}
+    >
+      {children}
+    </ErrorBoundary>
+  );
+}

apps/client/src/components/layouts/global/global-app-shell.tsx

@@ -1,9 +1,10 @@
 import { AppShell, Container } from "@mantine/core";
-import React, { useEffect, useRef, useState } from "react";
+import React, { Suspense, useEffect, useRef, useState } from "react";
 import { useLocation } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 import SettingsSidebar from "@/components/settings/settings-sidebar.tsx";
-import { useAtom } from "jotai";
+import { useAtom, useAtomValue } from "jotai";
+import { aiChatWindowOpenAtom } from "@/features/ai-chat/atoms/ai-chat-atom.ts";
 import {
   APP_NAVBAR_ID,
   NAVBAR_COLLAPSE_BREAKPOINT,
@@ -14,8 +15,6 @@ import {
 } from "@/components/layouts/global/hooks/atoms/sidebar-atom.ts";
 import { SpaceSidebar } from "@/features/space/components/sidebar/space-sidebar.tsx";
 import { AppHeader } from "@/components/layouts/global/app-header.tsx";
-import Aside from "@/components/layouts/global/aside.tsx";
-import AiChatWindow from "@/features/ai-chat/components/ai-chat-window.tsx";
 import GitmostGlobalBridge from "@/features/editor/gitmost/gitmost-global-bridge.tsx";
 import classes from "./app-shell.module.css";
 import { useToggleSidebar } from "@/components/layouts/global/hooks/hooks/use-toggle-sidebar.ts";
@@ -23,6 +22,21 @@ import GlobalSidebar from "@/components/layouts/global/global-sidebar.tsx";
 import { ASIDE_PANEL_ID } from "@/hooks/use-toggle-aside.tsx";
 import { MAIN_CONTENT_ID, SkipToMain } from "@/components/ui/skip-to-main.tsx";
 
+// Lazily load the AI chat window so the AI SDK runtime it pulls in is fetched
+// only after the user first opens the chat, instead of for every authenticated
+// user on load. The window itself renders null while closed, so there is no
+// behavior difference — it simply is not mounted until first opened.
+const AiChatWindow = React.lazy(
+  () => import("@/features/ai-chat/components/ai-chat-window.tsx"),
+);
+
+// The right aside hosts the comment panel and table of contents, both of which
+// pull in TipTap. It only ever renders on page routes, so lazy-loading it keeps
+// the whole editor engine out of the eager global-shell startup graph.
+const Aside = React.lazy(
+  () => import("@/components/layouts/global/aside.tsx"),
+);
+
 export default function GlobalAppShell({
   children,
 }: {
@@ -37,6 +51,15 @@ export default function GlobalAppShell({
   const [isResizing, setIsResizing] = useState(false);
   const sidebarRef = useRef(null);
 
+  // Latch: once the AI chat window has been opened, keep it mounted so an
+  // in-flight stream is never torn down. Before the first open the AI chat chunk
+  // is never fetched.
+  const aiChatOpen = useAtomValue(aiChatWindowOpenAtom);
+  const [aiChatEverOpened, setAiChatEverOpened] = useState(false);
+  useEffect(() => {
+    if (aiChatOpen) setAiChatEverOpened(true);
+  }, [aiChatOpen]);
+
   const startResizing = React.useCallback((mouseDownEvent) => {
     mouseDownEvent.preventDefault();
     setIsResizing(true);
@@ -67,14 +90,20 @@ export default function GlobalAppShell({
   );
 
   useEffect(() => {
-    //https://codesandbox.io/p/sandbox/kz9de
+    // Attach the global mousemove/mouseup only WHILE resizing (started on the
+    // handle's mousedown via startResizing → isResizing=true) and detach on
+    // mouseup (stopResizing → isResizing=false). Previously these listeners were
+    // attached for the whole app lifetime, so every mouse move over the app ran
+    // the resize handler.
+    // https://codesandbox.io/p/sandbox/kz9de
+    if (!isResizing) return;
     window.addEventListener("mousemove", resize);
     window.addEventListener("mouseup", stopResizing);
     return () => {
       window.removeEventListener("mousemove", resize);
       window.removeEventListener("mouseup", stopResizing);
     };
-  }, [resize, stopResizing]);
+  }, [isResizing, resize, stopResizing]);
 
   const location = useLocation();
   const isSettingsRoute = location.pathname.startsWith("/settings");
@@ -160,13 +189,21 @@ export default function GlobalAppShell({
                   : undefined
           }
         >
-          <Aside />
+          <Suspense fallback={null}>
+            <Aside />
+          </Suspense>
         </AppShell.Aside>
       )}
     </AppShell>
-    {/* Floating AI chat window. Mounted once globally; it is position: fixed
-        and self-hides when closed, so its place in the tree is not critical. */}
-    <AiChatWindow />
+    {/* Floating AI chat window. Mounted once globally on first open; it is
+        position: fixed and self-hides when closed, so its place in the tree is
+        not critical. Kept mounted after the first open so a live stream is not
+        aborted. */}
+    {aiChatEverOpened && (
+      <Suspense fallback={null}>
+        <AiChatWindow />
+      </Suspense>
+    )}
       {/* Global gitmost native bridge: registers listSpaces / listPages /
           createPageWithRecording on window.gitmost so the native host can
           create a page with a recording even when no page editor is open. */}

apps/client/src/components/layouts/global/layout.tsx

@@ -1,5 +1,7 @@
+import { Suspense, useEffect } from "react";
 import { UserProvider } from "@/features/user/user-provider.tsx";
 import { Outlet, useParams } from "react-router-dom";
+import { Center, Loader } from "@mantine/core";
 import GlobalAppShell from "@/components/layouts/global/global-app-shell.tsx";
 import { SearchSpotlight } from "@/features/search/components/search-spotlight.tsx";
 import { useGetSpaceBySlugQuery } from "@/features/space/queries/space-query.ts";
@@ -8,10 +10,39 @@ export default function Layout() {
   const { spaceSlug } = useParams();
   const { data: space } = useGetSpaceBySlugQuery(spaceSlug);
 
+  // Warm the (now route-split) editor chunk during idle time on authenticated
+  // routes, so the first navigation to a page renders from cache instead of a
+  // cold chunk fetch. Best-effort: gated on requestIdleCallback and never blocks
+  // startup — the dynamic import mirrors the App.tsx route lazy loader so both
+  // resolve to the same chunk.
+  useEffect(() => {
+    const ric =
+      typeof window !== "undefined" && (window as any).requestIdleCallback;
+    const warm = () => {
+      // Best-effort prefetch: a failed warm-up (offline, stale 404) is harmless
+      // and must not surface as an unhandledrejection.
+      void import("@/pages/page/page").catch(() => {});
+    };
+    if (ric) {
+      const id = ric(warm);
+      return () => (window as any).cancelIdleCallback?.(id);
+    }
+    const timer = setTimeout(warm, 2000);
+    return () => clearTimeout(timer);
+  }, []);
+
   return (
     <UserProvider>
       <GlobalAppShell>
-        <Outlet />
+        <Suspense
+          fallback={
+            <Center h="60vh">
+              <Loader size="sm" />
+            </Center>
+          }
+        >
+          <Outlet />
+        </Suspense>
       </GlobalAppShell>
       <SearchSpotlight spaceId={space?.id} />
     </UserProvider>

apps/client/src/components/ui/emoji-picker.tsx

@@ -5,7 +5,7 @@ import {
   Button,
   useMantineColorScheme,
 } from "@mantine/core";
-import { useClickOutside, useDisclosure, useWindowEvent } from "@mantine/hooks";
+import { useClickOutside, useDisclosure } from "@mantine/hooks";
 import { Suspense } from "react";
 import { useTranslation } from "react-i18next";
 
@@ -57,14 +57,22 @@ function EmojiPicker({
     [dropdown, target],
   );
 
-  // We need this because the default Mantine popover closeOnEscape does not work
-  useWindowEvent("keydown", (event) => {
-    if (opened && event.key === "Escape") {
-      event.stopPropagation();
-      event.preventDefault();
-      handlers.close();
-    }
-  });
+  // We need this because the default Mantine popover closeOnEscape does not work.
+  // Attach the global keydown ONLY while the picker is open (every tree row
+  // renders an EmojiPicker, so an always-on window listener meant ~20-30 idle
+  // keydown handlers firing on each keystroke).
+  useEffect(() => {
+    if (!opened) return;
+    const handleKeydown = (event: KeyboardEvent) => {
+      if (event.key === "Escape") {
+        event.stopPropagation();
+        event.preventDefault();
+        handlers.close();
+      }
+    };
+    window.addEventListener("keydown", handleKeydown);
+    return () => window.removeEventListener("keydown", handleKeydown);
+  }, [opened, handlers]);
 
   // emoji-mart's built-in autoFocus calls .focus() without preventScroll, which
   // makes the browser scroll every scrollable ancestor of the search input to

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

@@ -36,7 +36,7 @@ import {
   desktopSidebarAtom,
   mobileSidebarAtom,
 } from "@/components/layouts/global/hooks/atoms/sidebar-atom.ts";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import { usePageMetaQuery } from "@/features/page/queries/page-query.ts";
 import {
   pageEditorAtom,
   readOnlyEditorAtom,
@@ -86,11 +86,19 @@ const MIN_HEIGHT = 400;
 // Margin kept between the window and the viewport edges while dragging.
 const EDGE_MARGIN = 8;
 
-// #184 phase 1.5: hard cap on 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).
-const DEGRADED_POLL_MAX_MS = 10 * 60_000;
+// #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;
 
 /** Compact token formatter: 1.2M / 3.4k / 950. */
 function formatTokens(n: number): string {
@@ -237,7 +245,9 @@ export default function AiChatWindow() {
   // left partly off-screen).
   const [geom, setGeom] = useAtom(aiChatWindowGeomAtom);
 
-  const { data: chats } = useAiChatsQuery();
+  // Gated on windowOpen: the chat list is only needed once the window is open,
+  // so a closed window issues no chat-list request/refetch on navigation.
+  const { data: chats } = useAiChatsQuery(windowOpen);
   // Roles for the new-chat picker (any member may list them). Only fetched while
   // the window is open.
   const { data: roles } = useAiRolesQuery(windowOpen);
@@ -254,9 +264,12 @@ export default function AiChatWindow() {
   // 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).
   const [degradedPoll, setDegradedPoll] = useState(false);
-  const armedAtRef = useRef(0);
+  // #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) armedAtRef.current = Date.now();
+    if (active) lastActivityAtRef.current = Date.now();
     setDegradedPoll(active);
   }, []);
   // Reset the degraded poll whenever the open chat changes: it is scoped to the
@@ -269,18 +282,32 @@ export default function AiChatWindow() {
     useAiChatMessagesQuery(
       activeChatId ?? undefined,
       // DELIBERATELY DUMB (invariant 8 / task 2.4): poll every 2.5s while armed
-      // and under the 10-min 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 time cap is the only backstop.
+      // 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() - armedAtRef.current < DEGRADED_POLL_MAX_MS
+        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.
+      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.
+  useEffect(() => {
+    if (degradedPoll) lastActivityAtRef.current = Date.now();
+  }, [degradedPoll, messageRows]);
+
   // #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
   // resume attempt would only ever 204; gating ChatThread's resume on it avoids a
@@ -315,7 +342,7 @@ export default function AiChatWindow() {
   // reads/writes via its CASL-enforced page tools using the id.
   const pageRouteMatch = useMatch("/s/:spaceSlug/p/:pageSlug");
   const pageSlug = pageRouteMatch?.params?.pageSlug;
-  const { data: openPageData } = usePageQuery({
+  const { data: openPageData } = usePageMetaQuery({
     pageId: extractPageSlugId(pageSlug),
   });
   const openPage = openPageData

apps/client/src/features/ai-chat/components/chat-thread.test.tsx

@@ -28,7 +28,10 @@ const h = vi.hoisted(() => ({
         body: Record<string, unknown>;
       }) => { body: Record<string, unknown> };
       prepareReconnectToStreamRequest?: () => { api?: string };
-      fetch?: (input: unknown, init?: { method?: string }) => Promise<unknown>;
+      fetch?: (
+        input: unknown,
+        init?: { method?: string; body?: unknown },
+      ) => Promise<unknown>;
     },
   },
 }));
@@ -200,6 +203,244 @@ describe("ChatThread — send now (#198)", () => {
   });
 });
 
+// #396: in autonomous mode a live sendNow must additionally request the
+// AUTHORITATIVE server stop of the detached run (a local abort is only a client
+// disconnect the server ignores) and arm a bounded 409 retry so the re-POST
+// converges once the one-active-run slot frees. Legacy mode is unchanged.
+describe("ChatThread — send now server-stop + supersede retry (#396)", () => {
+  beforeEach(resetState);
+  afterEach(cleanup);
+
+  // A settled assistant tail => no mount resume (attemptResumeRef false), so the
+  // "Send now" button is visible for the NEW local streaming turn while
+  // autonomous runs are enabled.
+  const settledTail = () => [
+    row("u1", "user", undefined, "hi"),
+    row("a1", "assistant", "succeeded", "done"),
+  ];
+
+  it("autonomous: sendNow during a live stream calls onServerStop with the chat id", () => {
+    const { onServerStop } = renderThread({
+      autonomousRunsEnabled: true,
+      initialRows: settledTail(),
+    });
+    fireEvent.click(screen.getByTestId("queue-btn"));
+    fireEvent.click(screen.getByLabelText("Send now"));
+
+    expect(h.state.stop).toHaveBeenCalledTimes(1);
+    expect(onServerStop).toHaveBeenCalledWith("c1");
+  });
+
+  it("legacy (autonomous off): sendNow does NOT call onServerStop and does NOT retry the send", async () => {
+    const { onServerStop } = renderThread({
+      autonomousRunsEnabled: false,
+      initialRows: settledTail(),
+    });
+    fireEvent.click(screen.getByTestId("queue-btn"));
+    fireEvent.click(screen.getByLabelText("Send now"));
+    expect(onServerStop).not.toHaveBeenCalled();
+
+    // The supersede retry must NOT be armed: a POST that 409s is returned as-is
+    // (single fetch, no retry).
+    const fetchMock = vi
+      .fn()
+      .mockResolvedValue(
+        new Response(JSON.stringify({ code: "A_RUN_ALREADY_ACTIVE" }), {
+          status: 409,
+        }),
+      );
+    vi.stubGlobal("fetch", fetchMock);
+    let res!: Response;
+    await act(async () => {
+      res = (await h.state.transport!.fetch!("http://x", {
+        method: "POST",
+        body: "{}",
+      })) as Response;
+    });
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(res.status).toBe(409);
+  });
+
+  it("armed supersede send retries 409 A_RUN_ALREADY_ACTIVE and succeeds once the slot frees", async () => {
+    renderThread({ autonomousRunsEnabled: true, initialRows: settledTail() });
+    // Arm the retry by performing a live sendNow (autonomous branch sets the ref).
+    fireEvent.click(screen.getByTestId("queue-btn"));
+    fireEvent.click(screen.getByLabelText("Send now"));
+
+    const fetchMock = vi
+      .fn()
+      // First POST: the old detached run still holds the slot -> 409.
+      .mockResolvedValueOnce(
+        new Response(JSON.stringify({ code: "A_RUN_ALREADY_ACTIVE" }), {
+          status: 409,
+        }),
+      )
+      // Retry: the server stop settled the old run -> 200.
+      .mockResolvedValueOnce(new Response("ok", { status: 200 }));
+    vi.stubGlobal("fetch", fetchMock);
+
+    let res!: Response;
+    await act(async () => {
+      res = (await h.state.transport!.fetch!("http://x", {
+        method: "POST",
+        body: "{}",
+      })) as Response;
+    });
+    expect(fetchMock).toHaveBeenCalledTimes(2);
+    expect(res.status).toBe(200);
+  });
+
+  it("supersede retry is one-shot: a later send (ref cleared) does NOT retry a 409", async () => {
+    renderThread({ autonomousRunsEnabled: true, initialRows: settledTail() });
+    fireEvent.click(screen.getByTestId("queue-btn"));
+    fireEvent.click(screen.getByLabelText("Send now")); // arms the one-shot
+
+    // First armed send: immediately succeeds, consuming the arm.
+    let fetchMock = vi
+      .fn()
+      .mockResolvedValue(new Response("ok", { status: 200 }));
+    vi.stubGlobal("fetch", fetchMock);
+    await act(async () => {
+      await h.state.transport!.fetch!("http://x", {
+        method: "POST",
+        body: "{}",
+      });
+    });
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+
+    // A subsequent send is NOT armed -> a 409 is returned as-is (no retry).
+    fetchMock = vi.fn().mockResolvedValue(
+      new Response(JSON.stringify({ code: "A_RUN_ALREADY_ACTIVE" }), {
+        status: 409,
+      }),
+    );
+    vi.stubGlobal("fetch", fetchMock);
+    let res!: Response;
+    await act(async () => {
+      res = (await h.state.transport!.fetch!("http://x", {
+        method: "POST",
+        body: "{}",
+      })) as Response;
+    });
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(res.status).toBe(409);
+  });
+
+  it("supersede retry is bounded: exhaustion surfaces the 409 error", async () => {
+    renderThread({ autonomousRunsEnabled: true, initialRows: settledTail() });
+    fireEvent.click(screen.getByTestId("queue-btn"));
+    fireEvent.click(screen.getByLabelText("Send now"));
+
+    // Every attempt 409s -> after 4 attempts the last 409 surfaces.
+    const fetchMock = vi.fn().mockResolvedValue(
+      new Response(JSON.stringify({ code: "A_RUN_ALREADY_ACTIVE" }), {
+        status: 409,
+      }),
+    );
+    vi.stubGlobal("fetch", fetchMock);
+    let res!: Response;
+    await act(async () => {
+      res = (await h.state.transport!.fetch!("http://x", {
+        method: "POST",
+        body: "{}",
+      })) as Response;
+    });
+    // 4 attempts total (1 immediate + 3 backoff retries), then give up.
+    expect(fetchMock).toHaveBeenCalledTimes(4);
+    expect(res.status).toBe(409);
+  });
+
+  it("armed supersede send does NOT retry a non-409 status", async () => {
+    renderThread({ autonomousRunsEnabled: true, initialRows: settledTail() });
+    fireEvent.click(screen.getByTestId("queue-btn"));
+    fireEvent.click(screen.getByLabelText("Send now"));
+    const fetchMock = vi
+      .fn()
+      .mockResolvedValue(new Response("boom", { status: 500 }));
+    vi.stubGlobal("fetch", fetchMock);
+    let res!: Response;
+    await act(async () => {
+      res = (await h.state.transport!.fetch!("http://x", {
+        method: "POST",
+        body: "{}",
+      })) as Response;
+    });
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(res.status).toBe(500);
+  });
+
+  // Strand-path regression: sendNow arms the supersede retry, but if the promoted
+  // head is removed before the abort's onFinish lands, flushNext() sends nothing
+  // (returns false) and NO re-POST consumes the arm. The arm must be disarmed on
+  // that no-send branch so the NEXT unrelated NORMAL send does not inherit it and
+  // silently retry a genuine 409 (e.g. a legitimate two-tab conflict) 4x instead
+  // of surfacing it immediately.
+  it("strand-path: a stranded supersede arm (flushNext no-send) does NOT retry a later normal 409", async () => {
+    renderThread({ autonomousRunsEnabled: true, initialRows: settledTail() });
+    // Arm the retry via a live autonomous sendNow (promotes the head + arms).
+    fireEvent.click(screen.getByTestId("queue-btn"));
+    fireEvent.click(screen.getByLabelText("Send now"));
+
+    // Remove the promoted head BEFORE the abort lands, so flushNext() returns
+    // false (no POST) and the arm would strand without the disarm fix.
+    fireEvent.click(screen.getByLabelText("Remove queued message"));
+
+    // The abort's onFinish now takes the flushOnAbortRef branch, calls flushNext()
+    // which finds an empty queue and returns false -> the no-send disarm must run.
+    act(() => {
+      h.state.onFinish?.({
+        message: { id: "a1", role: "assistant", parts: [] },
+        isAbort: true,
+        isDisconnect: false,
+        isError: false,
+      });
+    });
+    // No re-POST was sent (nothing to flush).
+    expect(h.state.sendMessage).not.toHaveBeenCalled();
+
+    // A subsequent NORMAL send that 409s must be returned as-is (exactly 1 fetch):
+    // the stranded arm must NOT cause the genuine 409 to be retried.
+    const fetchMock = vi
+      .fn()
+      .mockResolvedValue(
+        new Response(JSON.stringify({ code: "A_RUN_ALREADY_ACTIVE" }), {
+          status: 409,
+        }),
+      );
+    vi.stubGlobal("fetch", fetchMock);
+    let res!: Response;
+    await act(async () => {
+      res = (await h.state.transport!.fetch!("http://x", {
+        method: "POST",
+        body: "{}",
+      })) as Response;
+    });
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(res.status).toBe(409);
+  });
+
+  it("armed supersede send does NOT retry a 409 with a different (non-A_RUN_ALREADY_ACTIVE) body", async () => {
+    renderThread({ autonomousRunsEnabled: true, initialRows: settledTail() });
+    fireEvent.click(screen.getByTestId("queue-btn"));
+    fireEvent.click(screen.getByLabelText("Send now"));
+    const fetchMock = vi.fn().mockResolvedValue(
+      new Response(JSON.stringify({ code: "SOMETHING_ELSE" }), {
+        status: 409,
+      }),
+    );
+    vi.stubGlobal("fetch", fetchMock);
+    let res!: Response;
+    await act(async () => {
+      res = (await h.state.transport!.fetch!("http://x", {
+        method: "POST",
+        body: "{}",
+      })) as Response;
+    });
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(res.status).toBe(409);
+  });
+});
+
 // #388: the editor selection is snapshotted at send time and nested inside
 // openPage on the wire. The getter is read live from a ref, so each send ships a
 // fresh snapshot.
@@ -739,3 +980,170 @@ function renderResumable(initialRows: IAiChatMessageRow[]) {
     act(() => view.rerender(<Wrapper rows={rows} />));
   return { rerender, onResumeFallback };
 }
+
+// #430: auto-reconnect to a DETACHED run after a LIVE SSE disconnect. The mount
+// path only resumes on mount/reload; these cover the missing trigger — a live
+// `isDisconnect` on onFinish must (backoff-)re-attach WITHOUT a reload, pin+strip
+// the live row to avoid duplicates, fall back to the degraded poll on a 204, and
+// exhaust to a manual Retry.
+describe("ChatThread — live reconnect after isDisconnect (#430)", () => {
+  // A LIVE local turn that just dropped: the settled tail existed before, and the
+  // partial assistant row lives only in `messages` (not persisted as a tail).
+  const settledTail = () => [
+    row("u1", "user", undefined, "hi"),
+    row("a1", "assistant", "succeeded", "done"),
+  ];
+  // The partial assistant message onFinish hands us for the dropped LIVE turn.
+  const liveMsg = {
+    id: "a2",
+    role: "assistant",
+    parts: [{ type: "text", text: "partial live answer" }],
+  };
+
+  beforeEach(() => {
+    resetState();
+    // status "ready": with a live disconnect the mock is not streaming, so the
+    // status==="streaming" auto-clear effect stays out of the way.
+    h.state.status = "ready";
+    vi.useFakeTimers();
+  });
+  afterEach(() => {
+    vi.useRealTimers();
+    cleanup();
+  });
+
+  // Render a NON-resuming mount (settled tail -> no mount resume) with autonomous
+  // runs on, then simulate a live disconnect via onFinish.
+  function renderLiveThenDisconnect() {
+    const view = renderThread({
+      autonomousRunsEnabled: true,
+      initialRows: settledTail(),
+    });
+    // The settled tail must NOT have triggered a mount resume.
+    expect(h.state.resumeStream).not.toHaveBeenCalled();
+    act(() => {
+      h.state.onFinish?.({
+        message: liveMsg,
+        isAbort: false,
+        isDisconnect: true,
+        isError: false,
+      });
+    });
+    return view;
+  }
+
+  // Fire the pending (scheduled) attempt for `attempt` (backoff = 1s,2s,4s,...).
+  function advanceToAttempt(attempt: number) {
+    act(() => {
+      vi.advanceTimersByTime(1000 * 2 ** (attempt - 1));
+    });
+  }
+
+  // Simulate the reconnect GET returning 204 (nothing live) so the transport's
+  // no-active-stream recovery runs.
+  async function reconnect204() {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn().mockResolvedValue({ status: 204, ok: false }),
+    );
+    await act(async () => {
+      await h.state.transport!.fetch!("http://x", { method: "GET" });
+    });
+  }
+
+  // Simulate the reconnect GET returning a live 2xx stream.
+  async function reconnect200() {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn().mockResolvedValue({ status: 200, ok: true }),
+    );
+    await act(async () => {
+      await h.state.transport!.fetch!("http://x", { method: "GET" });
+    });
+  }
+
+  it("calls resumeStream POST-mount (a live disconnect triggers a backoff reconnect)", () => {
+    renderLiveThenDisconnect();
+    // The banner shows immediately; the attach itself fires after the first backoff.
+    expect(screen.getByText(/reconnecting/i)).toBeTruthy();
+    expect(h.state.resumeStream).not.toHaveBeenCalled();
+    advanceToAttempt(1);
+    // resumeStream is now called AFTER mount — the bug was it only ever fired once
+    // on mount. The reconnect URL pins expect=live&anchor to OUR run.
+    expect(h.state.resumeStream).toHaveBeenCalledTimes(1);
+    expect(h.state.transport!.prepareReconnectToStreamRequest!().api).toBe(
+      "/api/ai-chat/runs/c1/stream?expect=live&anchor=a2",
+    );
+  });
+
+  it("strips the pinned live row before replay so content is NOT duplicated", () => {
+    renderLiveThenDisconnect();
+    advanceToAttempt(1);
+    // The attempt strips the anchor row from the store (the live replay rebuilds
+    // it). Apply the setMessages updater to prove it removes exactly the anchor.
+    const updater = h.state.setMessages.mock.calls.at(-1)![0] as (
+      prev: { id: string }[],
+    ) => { id: string }[];
+    expect(updater([{ id: "u1" }, { id: "a2" }])).toEqual([{ id: "u1" }]);
+  });
+
+  it("a live re-attach (2xx) clears the reconnect banner", async () => {
+    renderLiveThenDisconnect();
+    advanceToAttempt(1);
+    await reconnect200();
+    expect(screen.queryByText(/reconnecting/i)).toBeNull();
+  });
+
+  it("a 204 arms the degraded poll and backs off to the next attempt", async () => {
+    const { onResumeFallback } = renderLiveThenDisconnect();
+    advanceToAttempt(1);
+    expect(h.state.resumeStream).toHaveBeenCalledTimes(1);
+    await reconnect204();
+    // Fallback engaged: the degraded poll is armed (204 -> onNoActiveStream).
+    expect(onResumeFallback).toHaveBeenCalledWith(true);
+    // Still reconnecting — the banner advanced to attempt 2/5.
+    expect(screen.getByText(/reconnecting.*2\/5/i)).toBeTruthy();
+    // The next backoff fires attempt 2 (another resumeStream).
+    advanceToAttempt(2);
+    expect(h.state.resumeStream).toHaveBeenCalledTimes(2);
+  });
+
+  it("exhausts the attempt limit into a manual Retry, which restarts the sequence", async () => {
+    renderLiveThenDisconnect();
+    // Drive all 5 attempts, each failing with a 204.
+    for (let n = 1; n <= 5; n++) {
+      advanceToAttempt(n);
+      expect(h.state.resumeStream).toHaveBeenCalledTimes(n);
+      await reconnect204();
+    }
+    // The 5th 204 exhausted the cap -> the manual Retry replaces the banner.
+    expect(screen.queryByText(/reconnecting/i)).toBeNull();
+    const retry = screen.getByText("Retry");
+    expect(retry).toBeTruthy();
+    // Retry fires attempt 1 immediately (no backoff) — a 6th resumeStream.
+    act(() => {
+      fireEvent.click(retry);
+    });
+    expect(h.state.resumeStream).toHaveBeenCalledTimes(6);
+    expect(screen.getByText(/reconnecting/i)).toBeTruthy();
+  });
+
+  it("does NOT reconnect when autonomous runs are disabled", () => {
+    renderThread({ autonomousRunsEnabled: false, initialRows: settledTail() });
+    act(() => {
+      h.state.onFinish?.({
+        message: liveMsg,
+        isAbort: false,
+        isDisconnect: true,
+        isError: false,
+      });
+    });
+    expect(screen.queryByText(/reconnecting/i)).toBeNull();
+    // The terminal "connection lost" notice is shown instead (unchanged behavior).
+    expect(
+      screen.getByText("Connection lost — the answer was interrupted."),
+    ).toBeTruthy();
+    advanceToAttempt(1);
+    expect(h.state.resumeStream).not.toHaveBeenCalled();
+  });
+});

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

@@ -1,7 +1,17 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { useQueryClient } from "@tanstack/react-query";
 import { generateId } from "ai";
-import { ActionIcon, Box, Group, Stack, Text, Tooltip } from "@mantine/core";
+import {
+  ActionIcon,
+  Alert,
+  Box,
+  Button,
+  Group,
+  Loader,
+  Stack,
+  Text,
+  Tooltip,
+} from "@mantine/core";
 import {
   IconClockHour4,
   IconPlayerPlayFilled,
@@ -51,6 +61,45 @@ import classes from "@/features/ai-chat/components/ai-chat.module.css";
 // from the token rate.
 const STREAM_THROTTLE_MS = 50;
 
+// #430: auto-reconnect after a LIVE SSE disconnect of a DETACHED (autonomous) run.
+// The run keeps executing server-side, so instead of a dead "Lost connection"
+// banner we re-attach to the live tail through the SAME resumable machinery the
+// mount path uses. Attempts back off exponentially and are capped; on exhaustion
+// the user gets a manual Retry (the degraded poll keeps catching up underneath).
+const RECONNECT_MAX_ATTEMPTS = 5;
+// Backoff before attempt N (1-based): 1s, 2s, 4s, 8s, 16s.
+const RECONNECT_BASE_DELAY_MS = 1000;
+
+// #396: bounded retry for the "Interrupt and send now" re-send when it races the
+// authoritative server stop of the just-superseded detached run. The re-POST can
+// arrive before the old run has released the one-active-run slot, so the server
+// returns 409 A_RUN_ALREADY_ACTIVE. The server stop guarantees the slot frees, so
+// a few short backoffs converge. 4 total attempts: attempt 1 fires immediately,
+// then these are the waits BEFORE attempts 2, 3 and 4 (150ms, 300ms, 600ms). If
+// all 4 attempts 409, the last 409 surfaces (the banner) — acceptable per #396.
+const SUPERSEDE_RETRY_DELAYS_MS = [150, 300, 600];
+// The server error code that means "another run is already active for this chat".
+const A_RUN_ALREADY_ACTIVE = "A_RUN_ALREADY_ACTIVE";
+
+/**
+ * #396: defensively decide whether a 409 response is the one-active-run gate
+ * rejection (code A_RUN_ALREADY_ACTIVE) vs. some other 409. Reads a CLONE so the
+ * original response body stays intact for the caller when it is returned as-is.
+ * Any parse failure or unexpected shape => false (do NOT retry).
+ */
+async function isRunAlreadyActive(response: Response): Promise<boolean> {
+  try {
+    const body = (await response.clone().json()) as unknown;
+    return (
+      typeof body === "object" &&
+      body !== null &&
+      (body as { code?: unknown }).code === A_RUN_ALREADY_ACTIVE
+    );
+  } catch {
+    return false;
+  }
+}
+
 /** The page the user is currently viewing, sent as chat context. */
 export interface OpenPageContext {
   id: string;
@@ -175,6 +224,10 @@ export default function ChatThread({
   const reconcileTailRef = useRef(false);
   const noStreamHandledRef = useRef(false);
   const onNoActiveStreamRef = useRef<(() => void) | null>(null);
+  // #430: called from the transport's reconnect-GET success branch when a live
+  // stream re-attached (2xx, not 204) — clears the reconnect banner. Kept in a ref
+  // because the transport's fetch closure (useMemo([])) reads it live.
+  const onReconnectAttachedRef = useRef<(() => void) | null>(null);
   // Live mount flag. The attach GET and the resumed `onFinish` are async and can
   // land AFTER this thread unmounts (the parent remounts per chat via `key`); with
   // chatIdRef then pointing at the NEW chat, an ungated late callback would arm a
@@ -303,6 +356,26 @@ export default function ChatThread({
   const flushOnAbortRef = useRef(false);
   const interruptNextSendRef = useRef(false);
 
+  // #396: one-shot arm for the bounded 409 A_RUN_ALREADY_ACTIVE retry on the
+  // "Interrupt and send now" re-send in autonomous mode. sendNow triggers the
+  // authoritative server stop of the detached run, but that stop and the
+  // onFinish->flushNext re-POST race: the new POST can hit the one-active-run
+  // gate before the old detached run has settled, yielding a spurious 409. When
+  // this ref is armed, the transport's send path retries that 409 with a short
+  // bounded backoff (the server stop guarantees convergence). A normal send (ref
+  // not armed) must STILL fail a 409 instantly (e.g. a genuine two-tab conflict).
+  //
+  // INVARIANT: sendNow arms this only to be consumed by the ONE re-POST that
+  // flushNext fires from onFinish. But that re-POST does not always happen (the
+  // promoted head may be gone, the finish may be a resumed turn, or the arm may
+  // race a stale finish). To keep the arm strictly one-shot it is disarmed on
+  // EVERY path where the paired interrupt one-shots (flushOnAbortRef /
+  // interruptNextSendRef) are cleared without a POST: the transport POST branch
+  // consumes it (read-and-clear), the onFinish `!flushNext()` no-send branch
+  // clears it, and the isStreaming-defuse effect clears it symmetrically. So it
+  // can never leak into a later, unrelated send and retry that send's genuine 409.
+  const supersedeRetryRef = useRef(false);
+
   // #234 F5: the user pressed Stop while streaming a BRAND-NEW chat whose server
   // chat id has not been adopted yet (the `start` chunk carrying it hadn't landed
   // when Stop was pressed). A local SSE abort alone does NOT stop the DETACHED
@@ -359,7 +432,43 @@ export default function ChatThread({
           }`,
         }),
         fetch: async (input: RequestInfo | URL, init: RequestInit = {}) => {
-          if ((init.method ?? "GET") !== "GET") return fetch(input, init); // send path untouched
+          if ((init.method ?? "GET") !== "GET") {
+            // Send path (POST). #396: read-and-clear the one-shot supersede arm
+            // here so it is strictly scoped to THIS send. When unarmed, behave
+            // exactly as before — a single fetch, a 409 surfaces instantly (a
+            // genuine two-tab conflict must NOT be retried).
+            const supersede = supersedeRetryRef.current;
+            supersedeRetryRef.current = false;
+            if (!supersede) return fetch(input, init);
+            // Buffer a ReadableStream body once so each retry can replay it.
+            // DefaultChatTransport sends the body as a JSON STRING (replayable as
+            // is), but guard defensively in case a future SDK streams it.
+            let sendInit = init;
+            if (init.body instanceof ReadableStream) {
+              const buffered = await new Response(init.body).arrayBuffer();
+              sendInit = { ...init, body: buffered };
+            }
+            // Bounded retry: attempt 1 fires immediately, then wait between
+            // attempts per SUPERSEDE_RETRY_DELAYS_MS. Retry ONLY on a real
+            // 409 A_RUN_ALREADY_ACTIVE; any other status/body is returned as-is.
+            for (let attempt = 0; ; attempt++) {
+              const response = await fetch(input, sendInit);
+              if (
+                response.status !== 409 ||
+                attempt >= SUPERSEDE_RETRY_DELAYS_MS.length ||
+                !(await isRunAlreadyActive(response))
+              ) {
+                return response;
+              }
+              // The old detached run has not released the one-active-run slot
+              // yet; the server stop we requested guarantees it will, so back off
+              // and re-POST (the 409 fired before the user message was persisted,
+              // so re-POSTing is safe — no duplicate rows).
+              await new Promise((r) =>
+                setTimeout(r, SUPERSEDE_RETRY_DELAYS_MS[attempt]),
+              );
+            }
+          }
           // Reconnect GET: the SDK passes no AbortSignal, so wire our own controller
           // for observer Stop / unmount abort.
           const controller = new AbortController();
@@ -378,6 +487,10 @@ export default function ChatThread({
             // NOT drop the in-progress row or stop tracking the durable run.
             if (response.status === 204 || !response.ok)
               onNoActiveStreamRef.current?.();
+            // #430: a 2xx stream re-attached (live tail or finished-replay). Signal
+            // the reconnect controller to clear its banner. No-op outside an active
+            // reconnect sequence (e.g. the mount attach), so it is safe here.
+            else onReconnectAttachedRef.current?.();
             return response;
           } catch (err) {
             // Network throw: same no-onFinish recovery, then rethrow so the SDK
@@ -481,6 +594,31 @@ export default function ChatThread({
           );
         }
       }
+      // (2b) #430: a LIVE (non-resumed) detached run whose SSE just dropped. The
+      // server run keeps executing, so instead of a dead "Lost connection" banner
+      // start a reconnect sequence: pin the CURRENT streaming assistant row as the
+      // strip/anchor (the live tail is the already-shown partial in `messages`, not
+      // a persistent row) and re-attach to the live tail via the resumable machinery.
+      const startedReconnect =
+        isDisconnect &&
+        !wasResumed &&
+        autonomousRunsEnabled === true &&
+        mountedRef.current &&
+        message?.role === "assistant" &&
+        typeof message.id === "string";
+      if (startedReconnect) {
+        beginReconnect({
+          id: message.id,
+          role: "assistant",
+          content: "",
+          status: "streaming",
+          createdAt: new Date().toISOString(),
+          // Preserve the partial parts so a 204 restore (onNoActiveStream) re-shows
+          // what was on screen while the degraded poll catches the run up to
+          // terminal (rowToUiMessage prefers metadata.parts).
+          metadata: { parts: message.parts },
+        });
+      }
       // (3) Standard branches.
       // Forward the authoritative server chatId (streamed on the assistant
       // message metadata) so the parent adopts the REAL created chat id for a new
@@ -490,9 +628,11 @@ export default function ChatThread({
       onTurnFinished(extractServerChatId(message), threadKey);
       // Show a neutral "stopped" marker for an aborted turn; the red error banner
       // (via `error`) already covers isError, and a clean finish clears any marker.
+      // On a live disconnect that STARTED a reconnect, suppress the terminal
+      // "connection lost" notice — the reconnect banner takes over (#430).
       if (isError) setStopNotice(null);
       else if (isAbort) setStopNotice("manual");
-      else if (isDisconnect) setStopNotice("disconnect");
+      else if (isDisconnect) setStopNotice(startedReconnect ? null : "disconnect");
       else setStopNotice(null);
       // A resumed turn NEVER flushes the queue (invariant 7): skip BOTH the
       // flush-on-abort branch and the plain flush. The local streamer is the only
@@ -508,9 +648,14 @@ export default function ChatThread({
         setStopNotice(null);
         // If the promoted head vanished (e.g. the user removed it before the
         // abort landed) flushNext sends nothing — clear the one-shot interrupt
-        // tag so it can't leak onto the next unrelated send. On a real send the
-        // tag is consumed by prepareSendMessagesRequest and stays untouched.
-        if (!flushNext()) interruptNextSendRef.current = false;
+        // tag AND the #396 supersede arm so neither can leak onto the next
+        // unrelated send (no re-POST will consume the arm here). On a real send
+        // the tag is consumed by prepareSendMessagesRequest and the arm by the
+        // transport POST branch, so both stay untouched then.
+        if (!flushNext()) {
+          interruptNextSendRef.current = false;
+          supersedeRetryRef.current = false;
+        }
         return;
       }
       if (isAbort || isDisconnect || isError) return;
@@ -579,6 +724,106 @@ export default function ChatThread({
 
   const isStreaming = status === "submitted" || status === "streaming";
 
+  // #430: live-disconnect reconnect controller. `null` = idle; `{ trying, attempt }`
+  // = a backoff sequence is running (drives the "reconnecting… (N/max)" banner);
+  // `{ failed }` = attempts exhausted (drives the manual Retry). Mirrored into a ref
+  // so the transport/onNoActiveStream closures branch on the LIVE value.
+  type ReconnectState =
+    | null
+    | { phase: "trying"; attempt: number }
+    | { phase: "failed" };
+  const [reconnectState, setReconnectState] = useState<ReconnectState>(null);
+  const reconnectStateRef = useRef<ReconnectState>(null);
+  const setReconnectStatePair = useCallback((s: ReconnectState) => {
+    reconnectStateRef.current = s;
+    setReconnectState(s);
+  }, []);
+  const reconnectTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const clearReconnectTimer = useCallback(() => {
+    if (reconnectTimerRef.current) {
+      clearTimeout(reconnectTimerRef.current);
+      reconnectTimerRef.current = null;
+    }
+  }, []);
+
+  // One reconnect attempt — MIRRORS the mount strip/anchor path for the LIVE case.
+  // beginReconnect pinned strippedRowRef/stripRef to the run's assistant row, so:
+  //  - remove that row from the store (the mount path strips it from the SEED; here
+  //    it is already shown, so filter it out) — the live replay's `text-start` then
+  //    rebuilds it without DUPLICATING parts (the main dedup risk, #430);
+  //  - reset the one-shot 204 guard so onNoActiveStream can fire for THIS attempt;
+  //  - mark the turn resumed (invariant 7/8) so onFinish runs the recovery block and
+  //    never flushes the queue;
+  //  - resumeStream() -> prepareReconnectToStreamRequest builds
+  //    ?expect=live&anchor=<pinned id>, pinning the replay to OUR run (invariant 6).
+  const attemptReconnectOnce = useCallback(
+    (attempt: number) => {
+      if (!mountedRef.current) return;
+      const anchor = strippedRowRef.current;
+      if (anchor) {
+        setMessages((prev) => prev.filter((m) => m.id !== anchor.id));
+      }
+      noStreamHandledRef.current = false;
+      setResumedTurnPair(true);
+      setReconnectStatePair({ phase: "trying", attempt });
+      void resumeStream();
+    },
+    [setMessages, setResumedTurnPair, setReconnectStatePair, resumeStream],
+  );
+
+  // Schedule attempt `attempt` after an exponential backoff.
+  const scheduleReconnectAttempt = useCallback(
+    (attempt: number) => {
+      clearReconnectTimer();
+      setReconnectStatePair({ phase: "trying", attempt });
+      reconnectTimerRef.current = setTimeout(
+        () => attemptReconnectOnce(attempt),
+        RECONNECT_BASE_DELAY_MS * 2 ** (attempt - 1),
+      );
+    },
+    [clearReconnectTimer, setReconnectStatePair, attemptReconnectOnce],
+  );
+
+  // Start a fresh reconnect sequence, pinning `anchorRow` (the live run's assistant
+  // row) as the strip/anchor reused by every attempt.
+  const beginReconnect = useCallback(
+    (anchorRow: IAiChatMessageRow) => {
+      if (!autonomousRunsEnabled || !mountedRef.current) return;
+      strippedRowRef.current = anchorRow;
+      stripRef.current = true;
+      scheduleReconnectAttempt(1);
+    },
+    [autonomousRunsEnabled, scheduleReconnectAttempt],
+  );
+
+  // Manual Retry (shown once attempts are exhausted): restart at attempt 1 and fire
+  // immediately (the user asked for it now — no backoff).
+  const retryReconnect = useCallback(() => {
+    clearReconnectTimer();
+    attemptReconnectOnce(1);
+  }, [clearReconnectTimer, attemptReconnectOnce]);
+
+  // Live SSE re-attached (the reconnect GET returned a 2xx stream): clear the
+  // banner + any pending backoff. No-op outside a sequence (e.g. the mount attach).
+  const onReconnectAttached = useCallback(() => {
+    if (!mountedRef.current || !reconnectStateRef.current) return;
+    clearReconnectTimer();
+    setReconnectStatePair(null);
+  }, [clearReconnectTimer, setReconnectStatePair]);
+  onReconnectAttachedRef.current = onReconnectAttached;
+
+  // The reconnect GET could not attach (204 / error). onNoActiveStream has already
+  // armed the degraded poll (the robust fallback that drives the row to terminal
+  // from the DB), so this only decides the LIVE-attach retry: back off and try
+  // again up to the cap, else surface the manual Retry.
+  const onReconnectNoStream = useCallback(() => {
+    const s = reconnectStateRef.current;
+    if (s?.phase !== "trying") return;
+    if (s.attempt < RECONNECT_MAX_ATTEMPTS)
+      scheduleReconnectAttempt(s.attempt + 1);
+    else setReconnectStatePair({ phase: "failed" });
+  }, [scheduleReconnectAttempt, setReconnectStatePair]);
+
   // 204-handler (`onNoActiveStream`): the attach returned 204 — nothing live to
   // resume (overflow / begin-failure / after retention / anchor-mismatch). One-
   // shot via noStreamHandledRef (we do NOT null onNoActiveStreamRef). Exactly four
@@ -610,7 +855,17 @@ export default function ChatThread({
     // (d) 204 means onFinish will NOT fire — clear the suppression flag so it
     // cannot swallow the NEXT local turn's queue flush.
     setResumedTurnPair(false);
-  }, [setMessages, queryClient, onResumeFallback, setResumedTurnPair]);
+    // (e) #430: if this 204/error landed during a live-disconnect reconnect
+    // sequence, back off and retry the live attach (or give up to the manual
+    // Retry). The degraded poll armed in (c) is the fallback either way.
+    onReconnectNoStream();
+  }, [
+    setMessages,
+    queryClient,
+    onResumeFallback,
+    setResumedTurnPair,
+    onReconnectNoStream,
+  ]);
   onNoActiveStreamRef.current = onNoActiveStream;
 
   // Mount effect: kick off the resume attempt for a non-settled tail. Marking the
@@ -628,6 +883,9 @@ export default function ChatThread({
     return () => {
       mountedRef.current = false;
       attachAbortRef.current?.abort();
+      // #430: drop any pending reconnect backoff so it can't fire against the next
+      // chat this thread's refs are reused for.
+      if (reconnectTimerRef.current) clearTimeout(reconnectTimerRef.current);
     };
     // Mount-only by design; the parent remounts per chat via `key`.
     // eslint-disable-next-line react-hooks/exhaustive-deps
@@ -666,12 +924,27 @@ export default function ChatThread({
     if (tail.status !== "streaming") {
       reconcileTailRef.current = false;
       onResumeFallback?.(false);
+      // #430: the run reached its terminal state via the degraded poll — there is
+      // no live tail left to reconnect to, so drop any reconnect banner / Retry.
+      clearReconnectTimer();
+      setReconnectStatePair(null);
     }
     // onResumeFallback intentionally omitted (parent-stable callback); deps are
     // fixed by the resume design.
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [initialRows, isStreaming, setMessages]);
 
+  // #430: a real stream is live again — the reconnect re-attached to the live tail
+  // (status -> "streaming") OR the user started a new local turn. Either way clear
+  // the reconnect banner + any pending backoff. Gated on "streaming" (not the
+  // broader "submitted") so a still-pending attach GET does not clear prematurely.
+  useEffect(() => {
+    if (status === "streaming") {
+      clearReconnectTimer();
+      setReconnectStatePair(null);
+    }
+  }, [status, clearReconnectTimer, setReconnectStatePair]);
+
   // "Send now" on a queued message: interrupt the current turn and immediately
   // send THIS message, keeping the agent's partial output. Other queued messages
   // stay queued and flush normally after the new turn. Reuses the existing
@@ -691,6 +964,30 @@ export default function ChatThread({
         setQueue(promoteToHead(queuedRef.current, id));
         flushOnAbortRef.current = true;
         interruptNextSendRef.current = true;
+        // #396: in autonomous mode the turn is a DETACHED run — a local stop()
+        // is only a client disconnect the server ignores, so the run keeps going.
+        // The onFinish->flushNext re-POST would then hit the one-active-run gate
+        // and get a spurious 409 A_RUN_ALREADY_ACTIVE. Mirror handleStop: request
+        // the AUTHORITATIVE server stop so the detached run settles, and arm the
+        // one-shot bounded 409 retry BEFORE stop() so the re-send converges once
+        // the slot frees. Read chatId live from chatIdRef (adopted at the `start`
+        // chunk). If it is not known yet (brand-new chat, first moment of its
+        // first turn), defer the server stop via stopPendingRef exactly as
+        // handleStop does — the onServerChatId adoption effect fires it once the
+        // id lands; the retry stays armed so the re-send still converges then.
+        if (autonomousRunsEnabled) {
+          supersedeRetryRef.current = true; // arm the bounded 409 retry
+          if (chatIdRef.current) {
+            onServerStop?.(chatIdRef.current);
+          } else {
+            // Same #234-F5 sub-window limitation documented in handleStop: if the
+            // local abort below cancels the reader before the `start` chunk lands,
+            // the adoption effect never runs and the deferred stop never fires. Not
+            // a regression; at minimum we don't strand refs (the isStreaming effect
+            // defuses stopPendingRef on the next turn start).
+            stopPendingRef.current = true;
+          }
+        }
         stop(); // -> onFinish({ isAbort: true }) flushes the promoted head
       } else {
         // Nothing to interrupt: just send it now (no interrupt note).
@@ -702,7 +999,7 @@ export default function ChatThread({
         sendMessageRef.current?.({ text: msg.text });
       }
     },
-    [setQueue, stop, setResumedTurnPair],
+    [setQueue, stop, setResumedTurnPair, autonomousRunsEnabled, onServerStop],
   );
 
   // Stop the current turn. ALWAYS abort the local SSE (`stop()`) so the composer
@@ -719,6 +1016,9 @@ export default function ChatThread({
     // observer's Stop would otherwise leave the attach fetch running.
     attachAbortRef.current?.abort();
     stop();
+    // #430: pressing Stop also cancels an in-progress reconnect sequence.
+    clearReconnectTimer();
+    setReconnectStatePair(null);
     if (!autonomousRunsEnabled) return;
     if (chatIdRef.current) {
       onServerStop?.(chatIdRef.current);
@@ -740,7 +1040,13 @@ export default function ChatThread({
       // for this fix. Documented so a future change can address the abort-ordering.
       stopPendingRef.current = true;
     }
-  }, [stop, autonomousRunsEnabled, onServerStop]);
+  }, [
+    stop,
+    autonomousRunsEnabled,
+    onServerStop,
+    clearReconnectTimer,
+    setReconnectStatePair,
+  ]);
 
   // Clear the stopped marker as soon as a new turn begins streaming, and drop any
   // stale "Send now" interrupt flags. On the legit interrupt path both refs are
@@ -753,6 +1059,13 @@ export default function ChatThread({
       setStopNotice(null);
       flushOnAbortRef.current = false;
       interruptNextSendRef.current = false;
+      // #396: symmetric with the other one-shot interrupt flags — defuse a stale
+      // supersede arm that was set but whose expected re-POST never fired (the
+      // turn finished in the same tick as the click, or the promoted head was
+      // gone), so it can never leak into this (or a later) turn's send and retry
+      // that send's genuine 409. A legit arm is consumed by the transport POST
+      // branch before this new turn streams, so this does not clobber it.
+      supersedeRetryRef.current = false;
       // #234 F5: a new turn is starting — drop any pending deferred-stop from a
       // previous turn that never adopted an id, so it can never fire against this
       // (or a later) unrelated turn's run. A deferred stop for the CURRENT turn is
@@ -825,6 +1138,43 @@ export default function ChatThread({
           detail={errorView.detail}
           mb="xs"
         />
+      ) : reconnectState ? (
+        // #430: while auto-reconnecting to a detached run's live tail, show progress
+        // instead of a dead "Lost connection" banner; once attempts are exhausted,
+        // offer a manual Retry (the degraded poll keeps catching up underneath).
+        <Alert
+          variant="light"
+          color="gray"
+          p="xs"
+          mb="xs"
+          style={{ flexShrink: 0 }}
+        >
+          <Group gap={8} wrap="nowrap" align="center">
+            {reconnectState.phase === "trying" ? (
+              <>
+                <Loader size={14} color="gray" style={{ flex: "none" }} />
+                <Text size="sm" lh={1.3} c="dimmed">
+                  {t("Connection lost — reconnecting…")}
+                  {` (${reconnectState.attempt}/${RECONNECT_MAX_ATTEMPTS})`}
+                </Text>
+              </>
+            ) : (
+              <>
+                <Text size="sm" lh={1.3} c="dimmed" style={{ flex: 1 }}>
+                  {t("Couldn't reconnect to the answer.")}
+                </Text>
+                <Button
+                  size="compact-xs"
+                  variant="light"
+                  color="gray"
+                  onClick={retryReconnect}
+                >
+                  {t("Retry")}
+                </Button>
+              </>
+            )}
+          </Group>
+        </Alert>
       ) : stopNotice ? (
         <ChatStoppedNotice
           text={

apps/client/src/features/ai-chat/queries/ai-chat-query.ts

@@ -53,8 +53,12 @@ export const AI_CHAT_MESSAGES_RQ_KEY = (chatId: string) => [
   chatId,
 ];
 
-/** Paginated list of the current user's chats (auto-loads further pages). */
-export function useAiChatsQuery() {
+/**
+ * Paginated list of the current user's chats (auto-loads further pages).
+ * `enabled` (default true) lets the AI chat window skip fetching while it is
+ * closed — the list is only needed once the window is open.
+ */
+export function useAiChatsQuery(enabled: boolean = true) {
   const query = useInfiniteQuery({
     queryKey: AI_CHATS_RQ_KEY,
     queryFn: ({ pageParam }) => getAiChats({ cursor: pageParam, limit: 50 }),
@@ -63,6 +67,7 @@ export function useAiChatsQuery() {
       lastPage.meta.hasNextPage
         ? (lastPage.meta.nextCursor ?? undefined)
         : undefined,
+    enabled,
   });
 
   const data = useMemo<IPagination<IAiChat> | undefined>(() => {
@@ -93,6 +98,9 @@ export function useAiChatMessagesQuery(
   // follow the detached run to settle. The callback form lives in AiChatWindow;
   // threaded here verbatim so this query owns the polling. Undefined => no poll.
   refetchInterval?: number | false | (() => number | false),
+  // #344: gate the query so a backgrounded/hidden window stops issuing refetches
+  // and duplicating work. Defaults to enabled to preserve existing call-sites.
+  enabled: boolean = true,
 ) {
   const query = useInfiniteQuery({
     queryKey: AI_CHAT_MESSAGES_RQ_KEY(chatId ?? ""),
@@ -103,7 +111,7 @@ export function useAiChatMessagesQuery(
       lastPage.meta.hasNextPage
         ? (lastPage.meta.nextCursor ?? undefined)
         : undefined,
-    enabled: !!chatId,
+    enabled: !!chatId && enabled,
     refetchInterval,
   });
 

apps/client/src/features/comment/components/comment-content-view.test.tsx

@@ -15,6 +15,7 @@ vi.mock("@/features/comment/components/comment-editor", () => ({
 // case renders in isolation.
 vi.mock("@/features/page/queries/page-query.ts", () => ({
   usePageQuery: () => ({ data: undefined, isLoading: false, isError: false }),
+  usePageMetaQuery: () => ({ data: undefined, isLoading: false, isError: false }),
 }));
 vi.mock("@/features/share/queries/share-query.ts", () => ({
   useSharePageQuery: () => ({ data: undefined }),

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

@@ -22,7 +22,7 @@ import CommentEditor from "@/features/comment/components/comment-editor";
 import CommentActions from "@/features/comment/components/comment-actions";
 import { useFocusWithin } from "@mantine/hooks";
 import { IComment } from "@/features/comment/types/comment.types.ts";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import { usePageMetaQuery } from "@/features/page/queries/page-query.ts";
 import { extractPageSlugId } from "@/lib";
 import { useTranslation } from "react-i18next";
 import { useGetSpaceBySlugQuery } from "@/features/space/queries/space-query.ts";
@@ -56,7 +56,7 @@ export function buildChildrenByParent(
 function CommentListWithTabs({ onClose }: CommentListWithTabsProps) {
   const { t } = useTranslation();
   const { pageSlug } = useParams();
-  const { data: page } = usePageQuery({ pageId: extractPageSlugId(pageSlug) });
+  const { data: page } = usePageMetaQuery({ pageId: extractPageSlugId(pageSlug) });
   const {
     data: comments,
     isLoading: isCommentsLoading,

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

@@ -1,5 +1,8 @@
 import { atom } from "jotai";
-import { Editor } from "@tiptap/core";
+// Type-only: these atoms only hold an Editor reference for typing. A value
+// 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 { PageEditMode } from "@/features/user/types/user.types.ts";
 import type { DictationUnavailableReason } from "@/features/dictation/dictation-status";
 

apps/client/src/features/editor/components/audio/audio-menu.tsx

@@ -46,6 +46,13 @@ export function AudioMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip getAttributes unless an audio node is active. The menu
+      // only shows for an active audio node (shouldShow), so the null state while
+      // inactive is never rendered — behavior unchanged.
+      if (!ctx.editor.isActive("audio")) {
+        return null;
+      }
+
       const audioAttrs = ctx.editor.getAttributes("audio");
 
       return {

apps/client/src/features/editor/components/callout/callout-menu.tsx

@@ -43,8 +43,15 @@ export function CalloutMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip the per-type isActive() probes unless a callout is
+      // active. The menu only shows for an active callout (shouldShow), so the
+      // null state while inactive is never rendered — behavior unchanged.
+      if (!ctx.editor.isActive("callout")) {
+        return null;
+      }
+
       return {
-        isCallout: ctx.editor.isActive("callout"),
+        isCallout: true,
         isInfo: ctx.editor.isActive("callout", { type: "info" }),
         isNote: ctx.editor.isActive("callout", { type: "note" }),
         isSuccess: ctx.editor.isActive("callout", { type: "success" }),

apps/client/src/features/editor/components/code-block/code-block-view.tsx

@@ -22,6 +22,12 @@ export default function CodeBlockView(props: NodeViewProps) {
   const [isSelected, setIsSelected] = useState(false);
 
   useEffect(() => {
+    // #343 PART 6: `isSelected` only drives the mermaid source's visibility (the
+    // `hidden` prop below). For every non-mermaid code block it is never read,
+    // so skip the per-block `selectionUpdate` listener entirely — otherwise N
+    // code blocks each add a global listener + a setState on every caret move.
+    if (language !== "mermaid") return;
+
     const updateSelection = () => {
       const { state } = editor;
       const { from, to } = state.selection;
@@ -32,11 +38,14 @@ export default function CodeBlockView(props: NodeViewProps) {
       setIsSelected(isNodeSelected);
     };
 
+    // Initialize on attach so switching a block's language to "mermaid" reflects
+    // the current selection immediately (the listener was not running before).
+    updateSelection();
     editor.on("selectionUpdate", updateSelection);
     return () => {
       editor.off("selectionUpdate", updateSelection);
     };
-  }, [editor, getPos(), node.nodeSize]);
+  }, [editor, getPos(), node.nodeSize, language]);
 
   function changeLanguage(language: string) {
     setLanguageValue(language);

apps/client/src/features/editor/components/drawio/drawio-menu-lazy.tsx

@@ -0,0 +1,16 @@
+import { lazy, Suspense } from "react";
+import { EditorMenuProps } from "@/features/editor/components/table/types/types.ts";
+
+// Lazily load the drawio bubble menu so it is split out of the editor chunk and
+// fetched only when an editable editor is mounted (mirrors excalidraw-menu-lazy).
+const DrawioMenu = lazy(
+  () => import("@/features/editor/components/drawio/drawio-menu.tsx"),
+);
+
+export default function DrawioMenuLazy(props: EditorMenuProps) {
+  return (
+    <Suspense fallback={null}>
+      <DrawioMenu {...props} />
+    </Suspense>
+  );
+}

apps/client/src/features/editor/components/drawio/drawio-view-lazy.tsx

@@ -0,0 +1,17 @@
+import { lazy, Suspense } from "react";
+import { NodeViewProps } from "@tiptap/react";
+
+// Lazily load the drawio node view so the heavy react-drawio embed runtime is
+// split into its own chunk and fetched only when a drawio diagram is actually
+// rendered (mirrors excalidraw-view-lazy).
+const DrawioView = lazy(
+  () => import("@/features/editor/components/drawio/drawio-view.tsx"),
+);
+
+export default function DrawioViewLazy(props: NodeViewProps) {
+  return (
+    <Suspense fallback={null}>
+      <DrawioView {...props} />
+    </Suspense>
+  );
+}

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

@@ -1,5 +1,7 @@
 import type { Editor } from "@tiptap/react";
 import { useEditorState } from "@tiptap/react";
+import { undoDepth, redoDepth } from "@tiptap/pm/history";
+import { yUndoPluginKey } from "@tiptap/y-tiptap";
 
 export interface ToolbarState {
   isBold: boolean;
@@ -16,14 +18,45 @@ export interface ToolbarState {
   canRedo: boolean;
 }
 
-// Undo/redo come from either StarterKit's history or the Yjs collaboration
-// history extension. During the brief moment a page is rendered with the
-// static editor (mainExtensions only, undoRedo disabled), neither is loaded
-// and editor.can().undo/redo is undefined.
-function safeCan(editor: Editor, command: "undo" | "redo"): boolean {
-  const can = editor.can() as Record<string, unknown>;
-  const fn = can[command];
-  return typeof fn === "function" ? (fn as () => boolean)() : false;
+// Undo/redo availability, computed WITHOUT `editor.can().undo()/.redo()`.
+//
+// `editor.can()` runs the command as a dry-run (building a throwaway state +
+// transaction) — the most expensive work in this selector, and it ran on every
+// keystroke (and every REMOTE keystroke under collaboration). Instead we read
+// the history stack depth directly, which is a cheap plugin-state lookup and
+// mirrors exactly what the undo/redo commands themselves check:
+//
+//  - Collaboration (Yjs): the yjs UndoManager's undo/redo stack lengths — the
+//    same `undoStack.length === 0` / `redoStack.length === 0` guard the
+//    Collaboration extension's undo/redo commands use.
+//  - Plain history (templates / non-collab): prosemirror-history's undoDepth /
+//    redoDepth, which back the UndoRedo extension.
+//
+// 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.
+function historyAvailability(editor: Editor): {
+  canUndo: boolean;
+  canRedo: boolean;
+} {
+  const state = editor.state;
+
+  // Collaboration history (Yjs) takes precedence when present.
+  const yState = yUndoPluginKey.getState(state) as
+    | { undoManager?: { undoStack: unknown[]; redoStack: unknown[] } }
+    | undefined;
+  if (yState?.undoManager) {
+    return {
+      canUndo: yState.undoManager.undoStack.length > 0,
+      canRedo: yState.undoManager.redoStack.length > 0,
+    };
+  }
+
+  // Plain prosemirror-history (returns 0 when the history plugin is absent).
+  return {
+    canUndo: undoDepth(state) > 0,
+    canRedo: redoDepth(state) > 0,
+  };
 }
 
 export function useToolbarState(editor: Editor | null): ToolbarState | null {
@@ -31,6 +64,7 @@ export function useToolbarState(editor: Editor | null): ToolbarState | null {
     editor,
     selector: (ctx) => {
       if (!ctx.editor) return null;
+      const { canUndo, canRedo } = historyAvailability(ctx.editor);
       return {
         isBold: ctx.editor.isActive("bold"),
         isItalic: ctx.editor.isActive("italic"),
@@ -42,8 +76,8 @@ export function useToolbarState(editor: Editor | null): ToolbarState | null {
         isBulletList: ctx.editor.isActive("bulletList"),
         isOrderedList: ctx.editor.isActive("orderedList"),
         isTaskList: ctx.editor.isActive("taskList"),
-        canUndo: safeCan(ctx.editor, "undo"),
-        canRedo: safeCan(ctx.editor, "redo"),
+        canUndo,
+        canRedo,
       };
     },
   });

apps/client/src/features/editor/components/footnote/footnote-definition-view.tsx

@@ -49,19 +49,14 @@ export default function FootnoteDefinitionView(props: NodeViewProps) {
       className={classes.definition}
       style={{ ["--footnote-number" as any]: `"${number}"` }}
     >
-      {/* #146: contentDOM MUST be the first child — a non-editable marker before
+      {/* #146: contentDOM MUST be the first child — non-editable chrome before
           it makes click hit-testing snap the caret above. Content first; the
-          marker + back-link follow in DOM and are placed left/right via CSS
-          flex `order`. The second #146 mitigation lives in
+          back-link follows in DOM and is placed on the right via CSS flex. The
+          decorative "N." number is rendered inline via the .definitionContent
+          ::before rule (from the --footnote-number var), so no marker element
+          precedes the content. The second #146 mitigation lives in
           editor-paste-handler.tsx (reflowAfterPaste). */}
       <NodeViewContent className={classes.definitionContent} />
-      <span
-        className={classes.definitionMarker}
-        contentEditable={false}
-        aria-hidden="true"
-      >
-        {number}.
-      </span>
       {refCount > 1 ? (
         // Multiple references -> ↩ followed by one lettered link per occurrence.
         <span

apps/client/src/features/editor/components/footnote/footnote.module.css

@@ -81,34 +81,34 @@
 .definition {
   display: flex;
   align-items: flex-start;
-  /* Tight number→text spacing (~one space) so it reads like "1. text"
-     instead of leaving a wide gap after the period. */
-  gap: 0.4em;
+  /* Tight spacing between the content and the trailing ↩ back-link. */
+  gap: 0.3em;
   padding: 2px 0;
+  /* Footnotes read smaller than body text (16px). Matches .listHeading. */
+  font-size: var(--mantine-font-size-sm);
 }
 
-.definitionMarker {
-  order: -1; /* keep the "N." marker on the LEFT though it follows content in DOM (#146) */
-  flex: 0 0 auto;
-  min-width: 1.5em;
-  /* Right-align within the narrow column so the period sits next to the text
-     and multi-digit numbers (10, 11, …) stay aligned on their right edge. */
-  text-align: right;
-  font-variant-numeric: tabular-nums;
-  color: var(--mantine-color-dimmed);
-  user-select: none;
-}
-
+/* The "N." number is decorative (from the --footnote-number CSS var on the
+   wrapper, never in the document model) and is rendered inline at the start of
+   the first content line via ::before. This keeps text and wrapped lines flush
+   to the left margin — no hanging indent — while the editable contentDOM stays
+   the FIRST DOM child (#146). */
 .definitionContent {
   flex: 1 1 auto;
   min-width: 0;
 }
 
-/* The inner editable paragraph inherits `.ProseMirror p { margin: 0.5em 0 }`,
-   which pushes the first text line ~0.5em below the "N." marker (aligned to
-   flex-start), making the number float above the text. Drop the outer margins
-   so the marker and the first line share the same top edge — same approach
-   used for callouts in core.css. */
+.definitionContent > :first-child::before {
+  content: var(--footnote-number, "?") ". ";
+  color: var(--mantine-color-dimmed);
+  font-variant-numeric: tabular-nums;
+  user-select: none;
+}
+
+/* The inner editable paragraph inherits `.ProseMirror p { margin: 0.5em 0 }`.
+   Drop the outer margins so the definition sits tight to the heading above and
+   the ::before number aligns with the top of the row — same approach used for
+   callouts in core.css. */
 .definitionContent > :first-child {
   margin-top: 0;
 }

apps/client/src/features/editor/components/image/image-menu.tsx

@@ -38,6 +38,14 @@ export function ImageMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip the expensive per-keystroke work (getAttributes + the
+      // alignment isActive() probes) unless an image is actually active. The
+      // menu is only shown when an image is active (see shouldShow), so a null
+      // state while inactive is never rendered — behavior is unchanged.
+      if (!ctx.editor.isActive("image")) {
+        return null;
+      }
+
       const imageAttrs = ctx.editor.getAttributes("image");
 
       return {

apps/client/src/features/editor/components/link/link-view.tsx

@@ -24,7 +24,7 @@ import classes from "./link.module.css";
 import { useTranslation } from "react-i18next";
 import { INTERNAL_LINK_REGEX } from "@/lib/constants";
 import { LinkEditorPanel } from "@/features/editor/components/link/link-editor-panel.tsx";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import { usePageMetaQuery } from "@/features/page/queries/page-query.ts";
 import { useSharePageQuery } from "@/features/share/queries/share-query.ts";
 import { buildSharedPageUrl } from "@/features/page/page.utils.ts";
 import { extractPageSlugId } from "@/lib";
@@ -83,7 +83,7 @@ export default function LinkView(props: MarkViewProps) {
   const isPopoverVisible = popoverState !== "closed";
   const activeView = isPopoverVisible ? popoverState : lastOpenState.current;
 
-  const { data: linkedPage } = usePageQuery({
+  const { data: linkedPage } = usePageMetaQuery({
     pageId: isPopoverVisible && slugId && !isShareRoute ? slugId : null,
   });
 

apps/client/src/features/editor/components/math/math-block-lazy.tsx

@@ -0,0 +1,19 @@
+import { lazy, Suspense } from "react";
+import { NodeViewProps } from "@tiptap/react";
+
+// Lazily load the KaTeX-backed block math view so the katex chunk is fetched
+// only when a document actually contains a math node (mirrors the mermaid/
+// excalidraw lazy pattern). The local Suspense keeps a slow katex chunk from
+// crashing or blocking the whole editor: while it loads we render the raw
+// LaTeX source as a node-sized placeholder.
+const MathBlockView = lazy(
+  () => import("@/features/editor/components/math/math-block.tsx"),
+);
+
+export default function MathBlockViewLazy(props: NodeViewProps) {
+  return (
+    <Suspense fallback={<div data-katex="true">{props.node.attrs.text}</div>}>
+      <MathBlockView {...props} />
+    </Suspense>
+  );
+}

apps/client/src/features/editor/components/math/math-inline-lazy.tsx

@@ -0,0 +1,19 @@
+import { lazy, Suspense } from "react";
+import { NodeViewProps } from "@tiptap/react";
+
+// Lazily load the KaTeX-backed inline math view so the katex chunk is fetched
+// only when a document actually contains a math node (mirrors the mermaid/
+// excalidraw lazy pattern). The local Suspense keeps a slow katex chunk from
+// crashing or blocking the whole editor: while it loads we render the raw
+// LaTeX source as a node-sized placeholder.
+const MathInlineView = lazy(
+  () => import("@/features/editor/components/math/math-inline.tsx"),
+);
+
+export default function MathInlineViewLazy(props: NodeViewProps) {
+  return (
+    <Suspense fallback={<span data-katex="true">{props.node.attrs.text}</span>}>
+      <MathInlineView {...props} />
+    </Suspense>
+  );
+}

apps/client/src/features/editor/components/mention/mention-list.tsx

@@ -25,7 +25,7 @@ import { IconFileDescription, IconPlus } from "@tabler/icons-react";
 import { useSpaceQuery } from "@/features/space/queries/space-query.ts";
 import { useParams } from "react-router-dom";
 import { v7 as uuid7 } from "uuid";
-import { useAtom } from "jotai";
+import { useAtom, useSetAtom, useStore } from "jotai";
 import { currentUserAtom } from "@/features/user/atoms/current-user-atom.ts";
 import {
   MentionListProps,
@@ -34,7 +34,7 @@ import {
 import { IPage } from "@/features/page/types/page.types";
 import {
   useCreatePageMutation,
-  usePageQuery,
+  usePageMetaQuery,
 } from "@/features/page/queries/page-query";
 import { treeDataAtom } from "@/features/page/tree/atoms/tree-data-atom";
 import { treeModel } from "@/features/page/tree/model/tree-model";
@@ -50,12 +50,16 @@ const MentionList = forwardRef<any, MentionListProps>((props, ref) => {
   const [countAnnouncement, setCountAnnouncement] = useState("");
   const [selectionAnnouncement, setSelectionAnnouncement] = useState("");
   const { pageSlug, spaceSlug } = useParams();
-  const { data: page } = usePageQuery({ pageId: extractPageSlugId(pageSlug) });
+  const { data: page } = usePageMetaQuery({ pageId: extractPageSlugId(pageSlug) });
   const { data: space } = useSpaceQuery(spaceSlug);
   const [currentUser] = useAtom(currentUserAtom);
   const [renderItems, setRenderItems] = useState<MentionSuggestionItem[]>([]);
   const { t } = useTranslation();
-  const [data, setData] = useAtom(treeDataAtom);
+  // Setter-only: the tree value is read only imperatively inside createPage
+  // (via `store` below), never at render, so useSetAtom avoids re-rendering the
+  // mention popup on any tree event.
+  const setData = useSetAtom(treeDataAtom);
+  const store = useStore();
   const createPageMutation = useCreatePageMutation();
   const emit = useQueryEmit();
   const isInCommentContext = props.isInCommentContext ?? false;
@@ -272,9 +276,11 @@ const MentionList = forwardRef<any, MentionListProps>((props, ref) => {
         children: [],
       };
 
-      const lastIndex = data.length;
+      // Read the live tree imperatively at call time.
+      const currentTree = store.get(treeDataAtom);
+      const lastIndex = currentTree.length;
 
-      setData(treeModel.insert(data, parentId, newNode, lastIndex));
+      setData(treeModel.insert(currentTree, parentId, newNode, lastIndex));
 
       props.command({
         id: uuid7(),

apps/client/src/features/editor/components/mention/mention-view.tsx

@@ -2,7 +2,7 @@ import { NodeViewProps, NodeViewWrapper } from "@tiptap/react";
 import { ActionIcon, Anchor, Text } from "@mantine/core";
 import { IconFileDescription } from "@tabler/icons-react";
 import { Link, useLocation, useNavigate, useParams } from "react-router-dom";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import { usePageMetaQuery } from "@/features/page/queries/page-query.ts";
 import { useSharePageQuery } from "@/features/share/queries/share-query.ts";
 import {
   buildPageUrl,
@@ -36,7 +36,7 @@ export function MentionContent({ attrs }: { attrs: MentionAttrs }) {
     data: page,
     isLoading,
     isError,
-  } = usePageQuery({ pageId: isPageMention && !isShareRoute ? slugId : null });
+  } = usePageMetaQuery({ pageId: isPageMention && !isShareRoute ? slugId : null });
 
   const { data: sharedPage } = useSharePageQuery({
     pageId: isPageMention && isShareRoute ? slugId : undefined,

apps/client/src/features/editor/components/pdf/pdf-menu.tsx

@@ -25,6 +25,13 @@ export function PdfMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip getAttributes unless a pdf node is active. The menu
+      // only shows for an active pdf node (shouldShow), so the null state while
+      // inactive is never rendered — behavior unchanged.
+      if (!ctx.editor.isActive("pdf")) {
+        return null;
+      }
+
       const pdfAttrs = ctx.editor.getAttributes("pdf");
 
       return {

apps/client/src/features/editor/components/subpages/subpages-menu.tsx

@@ -70,7 +70,14 @@ export const SubpagesMenu = React.memo(
     // toggle without re-rendering on every keystroke.
     const isRecursive = useEditorState({
       editor,
-      selector: (ctx) => ctx.editor?.getAttributes("subpages")?.recursive ?? false,
+      // #343 PART 1: skip getAttributes unless a subpages node is active. The
+      // menu only shows for an active subpages node (shouldShow), so the value
+      // is only read then; getAttributes on an inactive node returns the default
+      // (recursive === false) anyway, so this is behavior-preserving.
+      selector: (ctx) =>
+        ctx.editor?.isActive("subpages")
+          ? (ctx.editor.getAttributes("subpages")?.recursive ?? false)
+          : false,
     });
 
     return (

apps/client/src/features/editor/components/table-of-contents/table-of-contents.tsx

@@ -4,6 +4,7 @@ import React, { FC, useEffect, useRef, useState } from "react";
 import classes from "./table-of-contents.module.css";
 import clsx from "clsx";
 import { Box, Text, Title } from "@mantine/core";
+import { useDebouncedCallback } from "@mantine/hooks";
 import { useTranslation } from "react-i18next";
 
 type TableOfContentsProps = {
@@ -79,13 +80,21 @@ export const TableOfContents: FC<TableOfContentsProps> = (props) => {
     setHeadingDOMNodes(result.nodes);
   };
 
+  // Debounce the update-driven rescan: `$nodes("heading")` scans every heading
+  // in the document, and it previously ran on EVERY keystroke while the TOC
+  // panel was open. The panel is derived UI, so recomputing ~300ms after typing
+  // settles keeps it correct without doing an all-headings scan per keystroke
+  // (#343, PART 7). `useDebouncedCallback` returns a stable reference and always
+  // invokes the latest `handleUpdate`.
+  const debouncedHandleUpdate = useDebouncedCallback(handleUpdate, 300);
+
   useEffect(() => {
-    props.editor?.on("update", handleUpdate);
+    props.editor?.on("update", debouncedHandleUpdate);
 
     return () => {
-      props.editor?.off("update", handleUpdate);
+      props.editor?.off("update", debouncedHandleUpdate);
     };
-  }, [props.editor]);
+  }, [props.editor, debouncedHandleUpdate]);
 
   useEffect(
     () => {

apps/client/src/features/editor/components/video/video-menu.tsx

@@ -31,6 +31,13 @@ export function VideoMenu({ editor }: EditorMenuProps) {
         return null;
       }
 
+      // #343 PART 1: skip getAttributes + alignment isActive() probes unless a
+      // video is active. The menu only shows for an active video (shouldShow),
+      // so the null state while inactive is never rendered — behavior unchanged.
+      if (!ctx.editor.isActive("video")) {
+        return null;
+      }
+
       const videoAttrs = ctx.editor.getAttributes("video");
 
       return {

apps/client/src/features/editor/extensions/extensions.ts

@@ -81,8 +81,8 @@ import {
   createResizeHandle,
   buildResizeClasses,
 } from "@/features/editor/components/common/node-resize-handles.ts";
-import MathInlineView from "@/features/editor/components/math/math-inline.tsx";
-import MathBlockView from "@/features/editor/components/math/math-block.tsx";
+import MathInlineView from "@/features/editor/components/math/math-inline-lazy.tsx";
+import MathBlockView from "@/features/editor/components/math/math-block-lazy.tsx";
 import ImageView from "@/features/editor/components/image/image-view.tsx";
 import CalloutView from "@/features/editor/components/callout/callout-view.tsx";
 import StatusView from "@/features/editor/components/status/status-view.tsx";
@@ -90,7 +90,7 @@ import VideoView from "@/features/editor/components/video/video-view.tsx";
 import AudioView from "@/features/editor/components/audio/audio-view.tsx";
 import AttachmentView from "@/features/editor/components/attachment/attachment-view.tsx";
 import CodeBlockView from "@/features/editor/components/code-block/code-block-view.tsx";
-import DrawioView from "../components/drawio/drawio-view";
+import DrawioView from "../components/drawio/drawio-view-lazy.tsx";
 import ExcalidrawView from "@/features/editor/components/excalidraw/excalidraw-view-lazy.tsx";
 import EmbedView from "@/features/editor/components/embed/embed-view.tsx";
 import HtmlEmbedView from "@/features/editor/components/html-embed/html-embed-view.tsx";

apps/client/src/features/editor/extensions/slash-command.ts

@@ -6,6 +6,23 @@ import getSuggestionItems from '@/features/editor/components/slash-menu/menu-ite
 
 export const slashMenuPluginKey = new PluginKey('slash-command');
 
+// getSuggestionItems fuzzy-matches EVERY command against the query (plus its
+// wrong-keyboard-layout remaps) and, while the slash menu is open, is invoked
+// TWICE per keystroke: once by the synchronous `allow` gate below and once by
+// the popup's `items` builder. A synchronous gating predicate can't be
+// debounced without breaking the suggestion decoration/activation, so instead we
+// memoize the LAST query's result: the two same-query calls in one keystroke
+// build the list only once, and the cache invalidates the moment the query
+// changes — so there is no stale-state risk (#343, PART 7).
+let lastQuery: string | null = null;
+let lastResult: ReturnType<typeof getSuggestionItems> | null = null;
+function suggestionItemsForQuery(query: string) {
+  if (query === lastQuery && lastResult) return lastResult;
+  lastQuery = query;
+  lastResult = getSuggestionItems({ query });
+  return lastResult;
+}
+
 // @ts-ignore
 const Command = Extension.create({
   name: 'slash-command',
@@ -38,7 +55,7 @@ const Command = Extension.create({
           // non-matching queries while keeping multi-word matches (e.g.
           // "/Heading 1") working.
           const query = state.doc.textBetween(range.from + 1, range.to);
-          const groups = getSuggestionItems({ query });
+          const groups = suggestionItemsForQuery(query);
           const hasMatches = Object.values(groups).some(
             (items) => items.length > 0,
           );
@@ -61,7 +78,9 @@ const Command = Extension.create({
 
 const SlashCommand = Command.configure({
   suggestion: {
-    items: getSuggestionItems,
+    // Share the per-query memo with `allow` so the pair of same-query calls in a
+    // single keystroke rebuilds the list once (#343, PART 7).
+    items: ({ query }: { query: string }) => suggestionItemsForQuery(query),
     render: renderItems,
   },
 });

apps/client/src/features/editor/gitmost/gitmost-global-bridge.tsx

@@ -1,8 +1,17 @@
 import { useEffect, useRef } from "react";
 import { useNavigate } from "react-router-dom";
 import { getDefaultStore } from "jotai";
-import { WebSocketStatus } from "@hocuspocus/provider";
-import { Editor } from "@tiptap/core";
+
+// Literal value of WebSocketStatus.Connected from @hocuspocus/provider. Inlined
+// so this always-mounted global bridge does not statically import
+// @hocuspocus/provider — that import pulls Yjs (and, through a shared chunk, the
+// whole TipTap engine) into the eager startup graph. yjsConnectionStatusAtom
+// already stores these raw status strings.
+const YJS_STATUS_CONNECTED = "connected";
+// Type-only: importing Editor as a type keeps @tiptap/core (the whole editor
+// engine) out of the eager global-shell graph — the bridge only uses it for
+// annotations/casts, never as a runtime value.
+import type { Editor } from "@tiptap/core";
 import {
   pageEditorAtom,
   yjsConnectionStatusAtom,
@@ -16,16 +25,19 @@ import {
   getSidebarPages,
 } from "@/features/page/services/page-service.ts";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
-import {
+// Types are erased at build time, so importing them does not pull the module's
+// runtime (which drags in @tiptap + the editor-ext barrel). The actual recording
+// helpers are dynamically imported at call time inside createPageWithRecording,
+// keeping the editor engine out of the eager global-shell startup graph — the
+// bridge is mounted for every authenticated user but recording is a rare,
+// native-host-driven action.
+import type {
   GitmostBridge,
   GitmostCreatePagePayload,
   GitmostCreatePageResult,
   GitmostListPagesPayload,
   GitmostListPagesResult,
   GitmostListSpacesResult,
-  gitmostDecodePayloadToFile,
-  gitmostInsertTranscriptIntoEditor,
-  gitmostUploadFileToEditor,
 } from "@/features/editor/gitmost/gitmost-recording.ts";
 
 // How long to wait for a freshly-navigated page's editor to mount, become
@@ -58,7 +70,7 @@ function gitmostWaitForEditor(
         !editor.isDestroyed &&
         editor.isEditable &&
         editorPageId === pageId &&
-        yjsStatus === WebSocketStatus.Connected;
+        yjsStatus === YJS_STATUS_CONNECTED;
       if (ready) {
         resolve(editor);
         return;
@@ -172,6 +184,15 @@ export default function GitmostGlobalBridge() {
           };
         }
 
+        // Load the recording helpers on demand (see the import note above). This
+        // is the only place they are needed, so the @tiptap/editor-ext code they
+        // pull in stays out of the eager startup graph.
+        const {
+          gitmostDecodePayloadToFile,
+          gitmostUploadFileToEditor,
+          gitmostInsertTranscriptIntoEditor,
+        } = await import("@/features/editor/gitmost/gitmost-recording.ts");
+
         // Validate/decode the recording BEFORE creating the page so a bad
         // payload never leaves an empty junk page behind. Per the createPage
         // error contract, any decode failure collapses to "insert-failed" (the

apps/client/src/features/editor/hooks/use-page-content-cache.test.ts

@@ -0,0 +1,100 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { renderHook, act } from "@testing-library/react";
+import type { MutableRefObject } from "react";
+import type { Editor } from "@tiptap/react";
+
+// Mock the app entry so importing the hook doesn't boot the whole app; the hook
+// only needs queryClient's cache read/write, which we stub here. Declared via
+// vi.hoisted so the spies exist before the hoisted vi.mock factory runs.
+const { getQueryData, setQueryData } = vi.hoisted(() => ({
+  getQueryData: vi.fn(() => undefined as unknown),
+  setQueryData: vi.fn(),
+}));
+vi.mock("@/main.tsx", () => ({
+  queryClient: { getQueryData, setQueryData },
+}));
+
+import { usePageContentCache } from "./use-page-content-cache";
+
+const SNAPSHOT = { type: "doc", content: [] };
+
+function makeFakeEditor(overrides: Partial<Editor> = {}): Editor {
+  return {
+    isEmpty: false,
+    isDestroyed: false,
+    getJSON: vi.fn(() => SNAPSHOT),
+    ...overrides,
+  } as unknown as Editor;
+}
+
+describe("usePageContentCache (#343 PART 3) — getJSON off the keystroke path", () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+    vi.clearAllMocks();
+    // A cached page exists so the write path runs.
+    getQueryData.mockReturnValue({ id: "p1", content: {} });
+  });
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("onUpdate (calling the debounced fn) does NOT call getJSON synchronously", () => {
+    const editor = makeFakeEditor();
+    const editorRef = { current: editor } as MutableRefObject<Editor | null>;
+
+    const { result } = renderHook(() =>
+      usePageContentCache(editorRef, "slug-1", 3000),
+    );
+
+    // Simulate a keystroke's onUpdate -> only schedules the debounce.
+    act(() => {
+      result.current();
+      result.current();
+      result.current();
+    });
+
+    // The whole-doc serialization must NOT have happened yet.
+    expect(editor.getJSON).not.toHaveBeenCalled();
+    expect(setQueryData).not.toHaveBeenCalled();
+
+    // Once the debounce window elapses, getJSON runs exactly once (not per call).
+    act(() => vi.advanceTimersByTime(3000));
+    expect(editor.getJSON).toHaveBeenCalledTimes(1);
+    expect(setQueryData).toHaveBeenCalledWith(["pages", "slug-1"], {
+      id: "p1",
+      content: SNAPSHOT,
+    });
+  });
+
+  it("flushes the pending snapshot on unmount so the last edit isn't lost", () => {
+    const editor = makeFakeEditor();
+    const editorRef = { current: editor } as MutableRefObject<Editor | null>;
+
+    const { result, unmount } = renderHook(() =>
+      usePageContentCache(editorRef, "slug-1", 3000),
+    );
+
+    act(() => result.current());
+    expect(editor.getJSON).not.toHaveBeenCalled();
+
+    // Navigation/unmount must flush (not drop) the pending write.
+    act(() => unmount());
+    expect(editor.getJSON).toHaveBeenCalledTimes(1);
+    expect(setQueryData).toHaveBeenCalledTimes(1);
+  });
+
+  it("skips the write when the editor is destroyed (flush racing teardown)", () => {
+    const editor = makeFakeEditor({ isDestroyed: true });
+    const editorRef = { current: editor } as MutableRefObject<Editor | null>;
+
+    const { result } = renderHook(() =>
+      usePageContentCache(editorRef, "slug-1", 3000),
+    );
+
+    act(() => result.current());
+    act(() => vi.advanceTimersByTime(3000));
+
+    expect(editor.getJSON).not.toHaveBeenCalled();
+    expect(setQueryData).not.toHaveBeenCalled();
+  });
+});

apps/client/src/features/editor/hooks/use-page-content-cache.ts

@@ -0,0 +1,50 @@
+import type { MutableRefObject } from "react";
+import { useDebouncedCallback } from "@mantine/hooks";
+import type { Editor } from "@tiptap/react";
+import { queryClient } from "@/main.tsx";
+import { IPage } from "@/features/page/types/page.types.ts";
+
+/**
+ * Off-keystroke local page-cache updater (issue #343, PART 3).
+ *
+ * The editor's `onUpdate` fires on every keystroke — and, under collaboration,
+ * on every REMOTE keystroke too. Serializing the WHOLE document with
+ * `editor.getJSON()` on that hot path is expensive, and the previous 3s debounce
+ * only guarded the cache WRITE, not the serialization: `getJSON()` still ran per
+ * keystroke.
+ *
+ * This hook moves the serialization INSIDE the debounced callback, so the
+ * full-doc traversal happens at most once per `delay`, not per keystroke. Call
+ * the returned function from `onUpdate` (it only schedules the debounce); the
+ * `getJSON()` snapshot is taken when the debounce fires.
+ *
+ * On unmount/navigation the pending snapshot is FLUSHED (via `flushOnUnmount`)
+ * so the last edits within the debounce window aren't lost from the local cache.
+ * The source of truth is collab/Yjs, but the cache must not go stale.
+ *
+ * IMPORTANT: call this hook BEFORE `useEditor`. React runs effect cleanups in
+ * declaration order on unmount, so the debounce's flush cleanup must be declared
+ * before `useEditor`'s teardown to run while the editor is still alive; the
+ * `isDestroyed` guard keeps a flush that still races teardown safe (it skips).
+ */
+export function usePageContentCache(
+  editorRef: MutableRefObject<Editor | null>,
+  slugId: string | undefined,
+  delay = 3000,
+) {
+  return useDebouncedCallback(
+    () => {
+      const e = editorRef.current;
+      if (!e || e.isDestroyed || e.isEmpty) return;
+      const pageData = queryClient.getQueryData<IPage>(["pages", slugId]);
+      if (pageData) {
+        // getJSON() (full-doc serialization) runs HERE, off the keystroke path.
+        queryClient.setQueryData(["pages", slugId], {
+          ...pageData,
+          content: e.getJSON(),
+        });
+      }
+    },
+    { delay, flushOnUnmount: true },
+  );
+}

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

@@ -59,10 +59,10 @@ import {
   handlePaste,
 } from "@/features/editor/components/common/editor-paste-handler.tsx";
 import ExcalidrawMenu from "./components/excalidraw/excalidraw-menu-lazy";
-import DrawioMenu from "./components/drawio/drawio-menu";
+import DrawioMenu from "./components/drawio/drawio-menu-lazy";
 import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
 import SearchAndReplaceDialog from "@/features/editor/components/search-and-replace/search-and-replace-dialog.tsx";
-import { useDebouncedCallback, useDocumentVisibility } from "@mantine/hooks";
+import { useDocumentVisibility } from "@mantine/hooks";
 import { useIdle } from "@/hooks/use-idle.ts";
 import { queryClient } from "@/main.tsx";
 import { IPage } from "@/features/page/types/page.types.ts";
@@ -79,6 +79,7 @@ import { PageEditMode } from "@/features/user/types/user.types.ts";
 import { jwtDecode } from "jwt-decode";
 import { searchSpotlight } from "@/features/search/constants.ts";
 import { useEditorScroll } from "./hooks/use-editor-scroll";
+import { usePageContentCache } from "./hooks/use-page-content-cache";
 import { useScrollRestoreOnSwap } from "./hooks/use-scroll-position";
 import { useSwapHeightReservation } from "./hooks/use-swap-height-reservation";
 import { EditorLinkMenu } from "@/features/editor/components/link/link-menu";
@@ -272,8 +273,13 @@ export default function PageEditor({
     }
   }, [isIdle, documentState, providersReady, resetIdle]);
 
-  // Attach here, to make sure the connection gets properly established
-  providersRef.current?.remote.attach();
+  // Attach the remote provider once it's ready (and again after a pageId swap
+  // recreates it) to make sure the connection gets properly established. This
+  // used to run in the render body — a side effect during render (#343, PART 7).
+  // `attach()` is idempotent, so re-running it on these deps is safe.
+  useEffect(() => {
+    providersRef.current?.remote.attach();
+  }, [providersReady, pageId]);
 
   const extensions = useMemo(() => {
     if (!providersReady || !providersRef.current || !currentUser?.user) {
@@ -288,6 +294,12 @@ export default function PageEditor({
     ];
   }, [providersReady, currentUser?.user]);
 
+  // getJSON() serialization + cache write live in the hook, off the keystroke
+  // path, and flush on unmount so the last snapshot survives navigation (#343).
+  // MUST be declared before useEditor: React runs effect cleanups in declaration
+  // order on unmount, so the flush must run before the editor is torn down.
+  const debouncedUpdateContent = usePageContentCache(editorRef, slugId);
+
   const editor = useEditor(
     {
       extensions,
@@ -392,11 +404,11 @@ export default function PageEditor({
           }
         }
       },
-      onUpdate({ editor }) {
-        if (editor.isEmpty) return;
-        const editorJson = editor.getJSON();
-        //update local page cache to reduce flickers
-        debouncedUpdateContent(editorJson);
+      onUpdate() {
+        // Only schedule the debounce here — the whole-doc getJSON() serialization
+        // happens INSIDE the debounced callback (see usePageContentCache), so it
+        // no longer runs synchronously on every (local or remote) keystroke.
+        debouncedUpdateContent();
       },
     },
     [pageId, editable, extensions],
@@ -442,17 +454,6 @@ export default function PageEditor({
     };
   }, [editor, pageId, editorIsEditable]);
 
-  const debouncedUpdateContent = useDebouncedCallback((newContent: any) => {
-    const pageData = queryClient.getQueryData<IPage>(["pages", slugId]);
-
-    if (pageData) {
-      queryClient.setQueryData(["pages", slugId], {
-        ...pageData,
-        content: newContent,
-      });
-    }
-  }, 3000);
-
   const handleActiveCommentEvent = (event) => {
     const { commentId, resolved } = event.detail;
 

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

@@ -24,7 +24,6 @@ export function useFavoritesQuery(type?: FavoriteType, spaceId?: string) {
     initialPageParam: undefined as string | undefined,
     getNextPageParam: (lastPage) =>
       lastPage.meta.hasNextPage ? lastPage.meta.nextCursor : undefined,
-    refetchOnMount: true,
   });
 }
 
@@ -32,7 +31,6 @@ export function useFavoriteIds(type: FavoriteType, spaceId?: string): Set<string
   const { data } = useQuery({
     queryKey: ["favorite-ids", type, spaceId],
     queryFn: () => getFavoriteIds(type, spaceId),
-    refetchOnMount: true,
   });
 
   const items = data?.items;

apps/client/src/features/page-details/components/page-details-aside.tsx

@@ -12,7 +12,7 @@ import { useAtomValue } from "jotai";
 import { useParams } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 import { extractPageSlugId } from "@/lib";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import { usePageMetaQuery } from "@/features/page/queries/page-query.ts";
 import { pageEditorAtom } from "@/features/editor/atoms/editor-atoms.ts";
 import { useBacklinksCountQuery } from "@/features/page-details/queries/backlinks-query.ts";
 import { BacklinksModal } from "./backlinks-modal";
@@ -23,7 +23,7 @@ import { LabelsSection } from "@/features/label/components/labels-section.tsx";
 
 export function PageDetailsAside() {
   const { pageSlug } = useParams();
-  const { data: page } = usePageQuery({
+  const { data: page } = usePageMetaQuery({
     pageId: extractPageSlugId(pageSlug),
   });
   const pageEditor = useAtomValue(pageEditorAtom);

apps/client/src/features/page/components/breadcrumbs/breadcrumb-path-equal.test.ts

@@ -0,0 +1,53 @@
+import { describe, it, expect, vi } from "vitest";
+import { SpaceTreeNode } from "@/features/page/tree/types";
+
+// breadcrumb.tsx transitively imports @/main.tsx (via usePageMetaQuery ->
+// queryClient), whose module body calls ReactDOM.createRoot on a null root in
+// jsdom. Stub it so importing the pure helper under test doesn't run that
+// (breadcrumbPathEqual does not use queryClient, so a dummy is enough).
+vi.mock("@/main.tsx", () => ({ queryClient: {} }));
+
+import { breadcrumbPathEqual } from "./breadcrumb";
+
+// breadcrumbPathEqual is the ONLY point where a false-positive equality would
+// leave a stale/incorrect breadcrumb trail on screen: it decides whether the
+// selectAtom hands back the same reference (no re-render) for the ancestor chain.
+// Pin both directions — a too-loose equality goes stale on a rename; a too-tight
+// one loses the perf win.
+const node = (over: Partial<SpaceTreeNode>): SpaceTreeNode =>
+  ({ id: "a", slugId: "sa", name: "A", icon: "📄", ...over }) as SpaceTreeNode;
+
+describe("breadcrumbPathEqual", () => {
+  it("both null → true", () => {
+    expect(breadcrumbPathEqual(null, null)).toBe(true);
+  });
+
+  it("same reference → true", () => {
+    const p = [node({})];
+    expect(breadcrumbPathEqual(p, p)).toBe(true);
+  });
+
+  it("equal by id/slugId/name/icon (different arrays) → true", () => {
+    expect(breadcrumbPathEqual([node({})], [node({})])).toBe(true);
+  });
+
+  it("one side null → false", () => {
+    expect(breadcrumbPathEqual([node({})], null)).toBe(false);
+    expect(breadcrumbPathEqual(null, [node({})])).toBe(false);
+  });
+
+  it("different length → false", () => {
+    expect(
+      breadcrumbPathEqual([node({})], [node({}), node({ id: "b" })]),
+    ).toBe(false);
+  });
+
+  it.each(["name", "icon", "slugId", "id"] as const)(
+    "a changed %s → false (breadcrumb must re-render)",
+    (field) => {
+      expect(
+        breadcrumbPathEqual([node({})], [node({ [field]: "CHANGED" })]),
+      ).toBe(false);
+    },
+  );
+});

apps/client/src/features/page/components/breadcrumbs/breadcrumb.tsx

@@ -1,7 +1,9 @@
 import { useAtomValue } from "jotai";
+import { selectAtom } from "jotai/utils";
 import { treeDataAtom } from "@/features/page/tree/atoms/tree-data-atom.ts";
-import React, { useCallback, useEffect, useState } from "react";
+import React, { useCallback, useEffect, useMemo, useState } from "react";
 import { computeBreadcrumbState } from "./breadcrumb.utils";
+import { findBreadcrumbPath } from "@/features/page/tree/utils";
 import {
   Button,
   Anchor,
@@ -18,7 +20,7 @@ import { SpaceTreeNode } from "@/features/page/tree/types.ts";
 import { IPage } from "@/features/page/types/page.types.ts";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
 import {
-  usePageQuery,
+  usePageMetaQuery,
   usePageBreadcrumbsQuery,
 } from "@/features/page/queries/page-query.ts";
 import { extractPageSlugId } from "@/lib";
@@ -32,39 +34,84 @@ function getTitle(name: string, icon: string) {
   return name;
 }
 
+/**
+ * Equality over a breadcrumb chain by the only fields the breadcrumb renders
+ * (id, slugId, name, icon). Lets the selectAtom below hand back the SAME
+ * reference when an unrelated tree mutation leaves THIS page's ancestor chain
+ * visually unchanged, so the breadcrumb no longer re-renders on every tree
+ * event (it previously subscribed to the whole treeDataAtom).
+ */
+export function breadcrumbPathEqual(
+  a: SpaceTreeNode[] | null,
+  b: SpaceTreeNode[] | null,
+): boolean {
+  if (a === b) return true;
+  if (!a || !b || a.length !== b.length) return false;
+  for (let i = 0; i < a.length; i++) {
+    if (
+      a[i].id !== b[i].id ||
+      a[i].slugId !== b[i].slugId ||
+      a[i].name !== b[i].name ||
+      a[i].icon !== b[i].icon
+    ) {
+      return false;
+    }
+  }
+  return true;
+}
+
 export default function Breadcrumb() {
   const { t } = useTranslation();
-  const treeData = useAtomValue(treeDataAtom);
   const [breadcrumbNodes, setBreadcrumbNodes] = useState<
     SpaceTreeNode[] | null
   >(null);
   const { pageSlug, spaceSlug } = useParams();
-  const { data: currentPage } = usePageQuery({
+  const { data: currentPage } = usePageMetaQuery({
     pageId: extractPageSlugId(pageSlug),
   });
+  const currentPageId = currentPage?.id;
   // The page's own ancestor chain, fetched independently of the lazily-built
   // sidebar tree so a deep page doesn't render a blank breadcrumb for seconds
   // while the tree backfills (#218).
-  const { data: ancestors } = usePageBreadcrumbsQuery(currentPage?.id);
+  const { data: ancestors } = usePageBreadcrumbsQuery(currentPageId);
   const isMobile = useMediaQuery("(max-width: 48em)");
 
+  // Narrowed subscription: instead of subscribing to the whole treeDataAtom and
+  // recomputing on every tree event, derive ONLY the current page's ancestor
+  // chain. The custom equality returns the previous reference when that chain is
+  // visually unchanged, so an unrelated tree mutation no longer re-renders this
+  // component. Mirrors computeBreadcrumbState's tree-hit branch
+  // (findBreadcrumbPath); the tree-miss/ancestors fallback is applied below.
+  const treePathAtom = useMemo(
+    () =>
+      selectAtom(
+        treeDataAtom,
+        (tree): SpaceTreeNode[] | null =>
+          currentPageId ? findBreadcrumbPath(tree, currentPageId) : null,
+        breadcrumbPathEqual,
+      ),
+    [currentPageId],
+  );
+  const treePath = useAtomValue(treePathAtom);
+
   useEffect(() => {
     if (!currentPage) return;
 
     // Selection/mapping + stale-clearing live in a pure, unit-tested helper
-    // (#218). It resolves the correct chain when possible and, on a transient
-    // miss, clears a chain left over from a previously-viewed page instead of
-    // showing the wrong trail — while keeping a chain already resolved for THIS
-    // page to avoid a blank flash.
+    // (#218). The tree-hit chain (treePath) always wins when present; otherwise
+    // fall back to the page's own ancestors and the stale-clearing logic — this
+    // reproduces computeBreadcrumbState(fullTree, ancestors, …) exactly, since
+    // its tree-hit branch is precisely findBreadcrumbPath(fullTree, pageId).
     setBreadcrumbNodes((previous) =>
+      treePath ??
       computeBreadcrumbState(
-        treeData,
+        null,
         ancestors as IPage[] | undefined,
         currentPage.id,
         previous,
       ),
     );
-  }, [currentPage?.id, treeData, ancestors]);
+  }, [currentPage?.id, treePath, ancestors]);
 
   const HiddenNodesTooltipContent = () =>
     breadcrumbNodes?.slice(1, -1).map((node) => (

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

@@ -24,7 +24,7 @@ import { historyAtoms } from "@/features/page-history/atoms/history-atoms.ts";
 import { useDisclosure, useHotkeys } from "@mantine/hooks";
 import { useClipboard } from "@/hooks/use-clipboard";
 import { useParams } from "react-router-dom";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import { usePageMetaQuery } from "@/features/page/queries/page-query.ts";
 import {
   useToggleTemporaryMutation,
   syncTemporaryExpiresInCache,
@@ -67,7 +67,7 @@ export default function PageHeaderMenu({ readOnly }: PageHeaderMenuProps) {
   const commentsTriggerProps = useAsideTriggerProps("comments");
   const tocTriggerProps = useAsideTriggerProps("toc");
   const { pageSlug } = useParams();
-  const { data: page } = usePageQuery({
+  const { data: page } = usePageMetaQuery({
     pageId: extractPageSlugId(pageSlug),
   });
   const isDeleted = !!page?.deletedAt;
@@ -146,7 +146,7 @@ function PageActionMenu({ readOnly }: PageActionMenuProps) {
   const [, setHistoryModalOpen] = useAtom(historyAtoms);
   const clipboard = useClipboard({ timeout: 500 });
   const { pageSlug, spaceSlug } = useParams();
-  const { data: page, isLoading } = usePageQuery({
+  const { data: page, isLoading } = usePageMetaQuery({
     pageId: extractPageSlugId(pageSlug),
   });
   const { handleDelete } = useTreeMutation(page?.spaceId ?? "");

apps/client/src/features/page/components/temporary-note-banner.tsx

@@ -10,7 +10,7 @@ import { IconClockHour4, IconTrash } from "@tabler/icons-react";
 import { useState } from "react";
 import { Trans, useTranslation } from "react-i18next";
 import { useTimeAgo } from "@/hooks/use-time-ago.tsx";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import { usePageMetaQuery } from "@/features/page/queries/page-query.ts";
 import { useTreeMutation } from "@/features/page/tree/hooks/use-tree-mutation.ts";
 import {
   useToggleTemporaryMutation,
@@ -35,7 +35,7 @@ type TemporaryNoteBannerProps = {
  */
 export function TemporaryNoteBanner({ slugId }: TemporaryNoteBannerProps) {
   const { t } = useTranslation();
-  const { data: page } = usePageQuery({ pageId: slugId });
+  const { data: page } = usePageMetaQuery({ pageId: slugId });
   const { data: space } = useGetSpaceBySlugQuery(page?.space?.slug);
   const spaceAbility = useSpaceAbility(space?.membership?.permissions);
   const expiresTimeAgo = useTimeAgo(page?.temporaryExpiresAt);

apps/client/src/features/page/queries/invalidate-on-update-page.test.ts

@@ -0,0 +1,149 @@
+import { describe, it, expect, beforeEach, vi } from "vitest";
+import type { IPage } from "@/features/page/types/page.types";
+
+// A fresh QueryClient stands in for the app singleton (importing the real
+// @/main.tsx would run ReactDOM.createRoot, which has no DOM root in jsdom). The
+// factory constructs it (QueryClient can't be referenced in vi.hoisted — that
+// runs before imports resolve); we import the SAME mocked instance back to seed
+// and assert on it.
+vi.mock("@/main.tsx", async () => {
+  const { QueryClient } = await import("@tanstack/react-query");
+  return { queryClient: new QueryClient() };
+});
+
+import { queryClient as h_qc } from "@/main.tsx";
+import { invalidateOnUpdatePage } from "./page-query";
+
+const h = { qc: h_qc };
+
+// invalidateOnUpdatePage is the field-only (title/icon) tree path: instead of a
+// blanket invalidate it patches the affected node IN PLACE in every cached embed
+// subtree. The undefined-guard is LOAD-BEARING: a title-only socket event carries
+// icon:undefined, and without the guard `{...p, icon: undefined}` would WIPE the
+// icon in every cached subtree.
+const page = (over: Partial<IPage>): IPage =>
+  ({ id: "p1", title: "Old", icon: "📄", spaceId: "s1" }) as IPage &
+    typeof over as IPage;
+
+describe("invalidateOnUpdatePage — pointwise embed-cache patch", () => {
+  beforeEach(() => {
+    h.qc.clear();
+  });
+
+  it("title-only event updates title but PRESERVES the icon (undefined-guard)", () => {
+    const key = ["page-tree", "parent-1"];
+    h.qc.setQueryData<IPage[]>(key, [
+      { id: "p1", title: "Old", icon: "📄", spaceId: "s1" } as IPage,
+      { id: "p2", title: "Other", icon: "📁", spaceId: "s1" } as IPage,
+    ]);
+
+    // icon passed as undefined (a title-only update)
+    invalidateOnUpdatePage(
+      "s1",
+      "parent-1",
+      "p1",
+      "New Title",
+      undefined as unknown as string,
+    );
+
+    const patched = h.qc.getQueryData<IPage[]>(key)!;
+    const p1 = patched.find((p) => p.id === "p1")!;
+    const p2 = patched.find((p) => p.id === "p2")!;
+    expect(p1.title).toBe("New Title");
+    expect(p1.icon).toBe("📄"); // preserved, not wiped
+    // Sibling node untouched.
+    expect(p2.title).toBe("Other");
+    expect(p2.icon).toBe("📁");
+  });
+
+  it("icon-only event updates icon but preserves the title", () => {
+    const key = ["page-tree", "parent-1"];
+    h.qc.setQueryData<IPage[]>(key, [
+      { id: "p1", title: "Keep", icon: "📄", spaceId: "s1" } as IPage,
+    ]);
+
+    invalidateOnUpdatePage(
+      "s1",
+      "parent-1",
+      "p1",
+      undefined as unknown as string,
+      "🚀",
+    );
+
+    const p1 = h.qc.getQueryData<IPage[]>(key)!.find((p) => p.id === "p1")!;
+    expect(p1.icon).toBe("🚀");
+    expect(p1.title).toBe("Keep");
+  });
+
+  // The sidebar-pages cache (InfiniteData) is patched on the same event. It must
+  // carry the SAME undefined-guard as the embed path above — otherwise a
+  // title-only event's icon:undefined would wipe the sidebar entry's icon.
+  const sidebarKey = ["sidebar-pages", { pageId: "parent-1", spaceId: "s1" }];
+  const seedSidebar = () =>
+    h.qc.setQueryData(sidebarKey, {
+      pageParams: [undefined],
+      pages: [
+        {
+          items: [
+            { id: "p1", title: "Old", icon: "📄", spaceId: "s1" } as IPage,
+            { id: "p2", title: "Other", icon: "📁", spaceId: "s1" } as IPage,
+          ],
+        },
+      ],
+    });
+  const sidebarItem = (id: string) => {
+    const data = h.qc.getQueryData(sidebarKey) as {
+      pages: { items: IPage[] }[];
+    };
+    return data.pages[0].items.find((p) => p.id === id)!;
+  };
+
+  it("sidebar cache: title-only event updates title but PRESERVES the icon", () => {
+    seedSidebar();
+
+    invalidateOnUpdatePage(
+      "s1",
+      "parent-1",
+      "p1",
+      "New Title",
+      undefined as unknown as string,
+    );
+
+    const p1 = sidebarItem("p1");
+    expect(p1.title).toBe("New Title");
+    expect(p1.icon).toBe("📄"); // preserved, not wiped
+    // Sibling untouched.
+    const p2 = sidebarItem("p2");
+    expect(p2.title).toBe("Other");
+    expect(p2.icon).toBe("📁");
+  });
+
+  it("sidebar cache: icon-only event updates icon but PRESERVES the title", () => {
+    seedSidebar();
+
+    invalidateOnUpdatePage(
+      "s1",
+      "parent-1",
+      "p1",
+      undefined as unknown as string,
+      "🚀",
+    );
+
+    const p1 = sidebarItem("p1");
+    expect(p1.icon).toBe("🚀");
+    expect(p1.title).toBe("Old"); // preserved, not wiped
+  });
+
+  it("does not touch a subtree that lacks the updated node", () => {
+    const otherKey = ["page-tree", "unrelated"];
+    const before = [
+      { id: "x1", title: "X", icon: "❌", spaceId: "s1" } as IPage,
+    ];
+    h.qc.setQueryData<IPage[]>(otherKey, before);
+
+    invalidateOnUpdatePage("s1", "parent-1", "p1", "New", "🚀");
+
+    // Same reference back — the subtree without p1 is left as-is.
+    expect(h.qc.getQueryData<IPage[]>(otherKey)).toBe(before);
+  });
+});

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

@@ -51,6 +51,10 @@ export function usePageQuery(
     queryFn: () => getPageById(pageInput),
     enabled: !!pageInput.pageId,
     staleTime: 5 * 60 * 1000,
+    // Keep the previously-loaded page visible while navigating to a new one
+    // instead of flashing a blank/skeleton frame (the new page's content
+    // streams in when ready). isLoading stays true only for the very first load.
+    placeholderData: keepPreviousData,
   });
 
   useEffect(() => {
@@ -66,6 +70,61 @@ export function usePageQuery(
   return query;
 }
 
+/**
+ * A page view that omits the large, frequently-changing `content` field. Every
+ * other field is preserved, so consumers that read only metadata (title, icon,
+ * permissions, id, creator, timestamps, …) keep working unchanged.
+ */
+export type IPageMeta = Omit<IPage, "content">;
+
+function selectPageMeta(page: IPage): IPageMeta {
+  // Drop `content`; react-query's structural sharing (replaceEqualDeep) then
+  // returns the SAME reference whenever the remaining fields are unchanged, so a
+  // pure content churn (typing / debouncedUpdateContent, collab `page.updated`)
+  // no longer changes this slice's identity and its ~13 subscribers don't
+  // re-render on every keystroke wave.
+  const { content: _content, ...meta } = page;
+  return meta as IPageMeta;
+}
+
+/**
+ * Metadata-only variant of {@link usePageQuery}. Shares the SAME query cache
+ * entry (`["pages", pageId]`, full object incl. content), but this hook returns
+ * a stable content-less slice so peripheral subscribers stop re-rendering on
+ * every content update. Use it anywhere the full `content` is not read.
+ */
+export function usePageMetaQuery(
+  pageInput: Partial<IPageInput>,
+): UseQueryResult<IPageMeta, Error> {
+  const query = useQuery({
+    queryKey: ["pages", pageInput.pageId],
+    queryFn: () => getPageById(pageInput),
+    enabled: !!pageInput.pageId,
+    staleTime: 5 * 60 * 1000,
+    select: selectPageMeta,
+    // Match usePageQuery: keep the previous page's metadata visible while
+    // navigating so the periphery (header, breadcrumb, …) doesn't flash blank.
+    placeholderData: keepPreviousData,
+  });
+
+  // Mirror usePageQuery's cross-key alias write so a page fetched by one
+  // identifier is also cached under the other. The cache stores the FULL page
+  // (select only narrows what THIS hook returns), so read the full object back
+  // from the cache and alias THAT — never the content-less slice.
+  useEffect(() => {
+    if (!query.data) return;
+    const full = queryClient.getQueryData<IPage>(["pages", pageInput.pageId]);
+    if (!full) return;
+    if (isValidUuid(pageInput.pageId)) {
+      queryClient.setQueryData(["pages", full.slugId], full);
+    } else {
+      queryClient.setQueryData(["pages", full.id], full);
+    }
+  }, [query.data]);
+
+  return query;
+}
+
 export function useCreatePageMutation() {
   const { t } = useTranslation();
   return useMutation<IPage, Error, Partial<IPageInput>>({
@@ -351,6 +410,12 @@ export function useRecentChangesQuery(spaceId?: string) {
     initialPageParam: undefined as string | undefined,
     getNextPageParam: (lastPage) =>
       lastPage.meta.hasNextPage ? lastPage.meta.nextCursor : undefined,
+    // KEEP refetchOnMount:true (against the global default false): recent-changes
+    // IS invalidated on page create/update/move/delete, but invalidateQueries only
+    // marks an UNMOUNTED query stale — it doesn't refetch it. The widget isn't
+    // always mounted, so an event that lands while it's unmounted leaves it stale,
+    // and the global refetchOnMount:false would not re-fetch on remount. The mount
+    // refetch closes that gap.
     refetchOnMount: true,
   });
 }
@@ -367,6 +432,9 @@ export function useCreatedByQuery(params?: {
     initialPageParam: undefined as string | undefined,
     getNextPageParam: (lastPage) =>
       lastPage.meta.hasNextPage ? lastPage.meta.nextCursor : undefined,
+    // KEEP refetchOnMount:true: the "created-by" key is never invalidated (no
+    // socket/mutation path), so the mount refetch is its ONLY freshness mechanism
+    // — without it the list shows stale cache on navigation.
     refetchOnMount: true,
   });
 }
@@ -380,8 +448,14 @@ export function useDeletedPagesQuery(
     queryFn: () => getDeletedPages(spaceId, params),
     enabled: !!spaceId,
     placeholderData: keepPreviousData,
-    refetchOnMount: true,
     staleTime: 0,
+    // KEEP refetchOnMount:true: ["trash-list"] IS invalidated by the
+    // move-to-trash / delete / restore mutations, but invalidateQueries only marks
+    // an unmounted query stale — it doesn't refetch it. The trash panel isn't
+    // usually mounted when a page is trashed, so on opening it the global
+    // refetchOnMount:false would show a stale list; the mount refetch closes that.
+    // (Do NOT remove the three trash-list invalidations — they are not dead code.)
+    refetchOnMount: true,
   });
 }
 
@@ -516,7 +590,35 @@ export function invalidateOnUpdatePage(
   title: string,
   icon: string,
 ) {
-  invalidatePageTree();
+  // Scoped page-tree refresh (was a blanket `invalidatePageTree()`): this is the
+  // FIELD-only update path (title/icon — no structural change), and the sidebar
+  // tree is already updated pointwise (applyUpdateOne / optimistic setData) plus
+  // via the sidebar-pages cache below. Invalidating ALL ["page-tree"] queries
+  // here refetched every open recursive subpages-embed block on each
+  // rename/icon-change — pure duplicate work. Instead patch just the affected
+  // node IN PLACE in every cached embed subtree: same visible result, no network
+  // churn, no full embed-tree rebuild. Structural events (create/move/delete)
+  // keep the blanket invalidate in their own helpers.
+  const pageTreeMatches = queryClient.getQueriesData<IPage[]>({
+    queryKey: ["page-tree"],
+  });
+  pageTreeMatches.forEach(([key, items]) => {
+    if (!items || !items.some((p) => p.id === id)) return;
+    queryClient.setQueryData<IPage[]>(key, (old) =>
+      old?.map((p) =>
+        p.id === id
+          ? {
+              ...p,
+              // Guard undefined so a title-only event can't wipe the icon (and
+              // vice versa) in the embed cache.
+              ...(title !== undefined ? { title } : {}),
+              ...(icon !== undefined ? { icon } : {}),
+            }
+          : p,
+      ),
+    );
+  });
+
   let queryKey: QueryKey = null;
   if (parentPageId === null) {
     queryKey = ["root-sidebar-pages", spaceId];
@@ -534,7 +636,14 @@ export function invalidateOnUpdatePage(
           ...page,
           items: page.items.map((sidebarPage: IPage) =>
             sidebarPage.id === id
-              ? { ...sidebarPage, title: title, icon: icon }
+              ? {
+                  ...sidebarPage,
+                  // Guard undefined so a title-only event can't wipe the icon
+                  // (and vice versa) in the sidebar-pages cache — mirrors the
+                  // embed-cache patch above.
+                  ...(title !== undefined ? { title } : {}),
+                  ...(icon !== undefined ? { icon } : {}),
+                }
               : sidebarPage,
           ),
         })),

apps/client/src/features/page/trash/components/deleted-page-banner.tsx

@@ -7,7 +7,7 @@ import { useRestorePageModal } from "@/features/page/hooks/use-restore-page-moda
 import { useDeletePageModal } from "@/features/page/hooks/use-delete-page-modal.tsx";
 import {
   useDeletePageMutation,
-  usePageQuery,
+  usePageMetaQuery,
   useRestorePageMutation,
 } from "@/features/page/queries/page-query.ts";
 import { getSpaceUrl } from "@/lib/config.ts";
@@ -25,7 +25,7 @@ type DeletedPageBannerProps = {
 export function DeletedPageBanner({ slugId }: DeletedPageBannerProps) {
   const { t } = useTranslation();
   const navigate = useNavigate();
-  const { data: page } = usePageQuery({ pageId: slugId });
+  const { data: page } = usePageMetaQuery({ pageId: slugId });
   const { data: space } = useGetSpaceBySlugQuery(page?.space?.slug);
   const spaceAbility = useSpaceAbility(space?.membership?.permissions);
   const deletedTimeAgo = useTimeAgo(page?.deletedAt);

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

@@ -1,4 +1,4 @@
-import { useAtom } from "jotai";
+import { useSetAtom, useStore } from "jotai";
 import { useTranslation } from "react-i18next";
 import { useParams } from "react-router-dom";
 import { ActionIcon, Menu, rem } from "@mantine/core";
@@ -52,7 +52,11 @@ export function NodeMenu({ node, canEdit }: NodeMenuProps) {
   const clipboard = useClipboard({ timeout: 500 });
   const { spaceSlug } = useParams();
   const { handleDelete } = useTreeMutation(node.spaceId);
-  const [data, setData] = useAtom(treeDataAtom);
+  // Setter-only: the tree value is read only imperatively inside the duplicate
+  // handler (via `store` below), never at render, so useSetAtom avoids
+  // re-rendering every row's NodeMenu on any tree event.
+  const setData = useSetAtom(treeDataAtom);
+  const store = useStore();
   const emit = useQueryEmit();
   const [exportOpened, { open: openExportModal, close: closeExportModal }] =
     useDisclosure(false);
@@ -125,8 +129,8 @@ export function NodeMenu({ node, canEdit }: NodeMenuProps) {
     try {
       const duplicatedPage = await duplicatePage({ pageId: node.id });
 
-      // figure out parent + insertion index
-      const siblings = treeModel.siblingsOf(data, node.id);
+      // figure out parent + insertion index (read the live tree imperatively)
+      const siblings = treeModel.siblingsOf(store.get(treeDataAtom), node.id);
       const parentId = siblings?.parentId ?? null;
       const currentIndex = siblings?.index ?? 0;
       const newIndex = currentIndex + 1;

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

@@ -1,6 +1,6 @@
 import { useRef } from "react";
 import { Link, useParams } from "react-router-dom";
-import { useAtom } from "jotai";
+import { useAtom, useSetAtom } from "jotai";
 import { useTranslation } from "react-i18next";
 import { ActionIcon, rem, Tooltip } from "@mantine/core";
 import {
@@ -51,7 +51,11 @@ export function SpaceTreeRow({
   const { t } = useTranslation();
   const { spaceSlug } = useParams();
   const updatePageMutation = useUpdatePageMutation();
-  const [, setTreeData] = useAtom(treeDataAtom);
+  // Setter-only: subscribing to the whole treeDataAtom (via useAtom) re-rendered
+  // every virtualized row on any tree event, bypassing the DocTreeRow memo. This
+  // row never reads the tree value, only writes it, so useSetAtom avoids the
+  // value subscription.
+  const setTreeData = useSetAtom(treeDataAtom);
   const emit = useQueryEmit();
   const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
   const [mobileSidebarOpened] = useAtom(mobileSidebarAtom);

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

@@ -35,6 +35,7 @@ vi.mock("@/features/page/queries/page-query.ts", () => ({
     isFetching: false,
   }),
   usePageQuery: () => ({ data: undefined }),
+  usePageMetaQuery: () => ({ data: undefined }),
   fetchAllAncestorChildren: (...args: unknown[]) =>
     fetchAllAncestorChildrenMock(...args),
 }));

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

@@ -26,6 +26,7 @@ vi.mock("@/features/page/queries/page-query.ts", () => ({
     isFetching: false,
   }),
   usePageQuery: () => ({ data: undefined }),
+  usePageMetaQuery: () => ({ data: undefined }),
   fetchAllAncestorChildren: vi.fn(),
 }));
 

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

@@ -15,7 +15,7 @@ import { notifications } from "@mantine/notifications";
 import {
   fetchAllAncestorChildren,
   useGetRootSidebarPagesQuery,
-  usePageQuery,
+  usePageMetaQuery,
 } from "@/features/page/queries/page-query.ts";
 import classes from "@/features/page/tree/styles/tree.module.css";
 import { treeDataAtom } from "@/features/page/tree/atoms/tree-data-atom.ts";
@@ -76,7 +76,7 @@ const SpaceTree = forwardRef<SpaceTreeApi, SpaceTreeProps>(function SpaceTree(
   const [isDataLoaded, setIsDataLoaded] = useState(false);
   const spaceIdRef = useRef(spaceId);
   spaceIdRef.current = spaceId;
-  const { data: currentPage } = usePageQuery({
+  const { data: currentPage } = usePageMetaQuery({
     pageId: extractPageSlugId(pageSlug),
   });
 

apps/client/src/features/page/tree/hooks/use-tree-mutation.ts

@@ -1,5 +1,5 @@
 import { useCallback } from "react";
-import { useAtom, useSetAtom, useStore } from "jotai";
+import { useSetAtom, useStore } from "jotai";
 import { notifications } from "@mantine/notifications";
 import { useTranslation } from "react-i18next";
 import { useNavigate, useParams } from "react-router-dom";
@@ -34,7 +34,10 @@ export type UseTreeMutation = {
 
 export function useTreeMutation(spaceId: string): UseTreeMutation {
   const { t } = useTranslation();
-  const [, setData] = useAtom(treeDataAtom);
+  // Setter-only: this hook never reads the tree reactively (handlers read the
+  // live value imperatively via `store` below), so useSetAtom avoids
+  // re-rendering SpaceSidebar on every tree event.
+  const setData = useSetAtom(treeDataAtom);
   // `store` reads the *current* treeDataAtom imperatively in handlers — avoids
   // stale-closure issues when the caller updates the tree (e.g. lazy-load
   // children) and then immediately invokes a handler.

apps/client/src/features/share/components/share-layout.tsx

@@ -1,10 +1,20 @@
+import { Suspense } from "react";
 import { Outlet } from "react-router-dom";
+import { Center, Loader } from "@mantine/core";
 import ShareShell from "@/features/share/components/share-shell.tsx";
 
 export default function ShareLayout() {
   return (
     <ShareShell>
-      <Outlet />
+      <Suspense
+        fallback={
+          <Center h="60vh">
+            <Loader size="sm" />
+          </Center>
+        }
+      >
+        <Outlet />
+      </Suspense>
     </ShareShell>
   );
 }

apps/client/src/features/share/components/share-modal.test.tsx

@@ -28,6 +28,7 @@ vi.mock("@/features/share/queries/share-query.ts", () => ({
 
 vi.mock("@/features/page/queries/page-query.ts", () => ({
   usePageQuery: () => ({ data: { id: "page-1", title: "Doc" } }),
+  usePageMetaQuery: () => ({ data: { id: "page-1", title: "Doc" } }),
 }));
 
 vi.mock("@/features/space/queries/space-query.ts", () => ({

apps/client/src/features/share/components/share-modal.tsx

@@ -20,7 +20,7 @@ import {
 import { Link, useParams } from "react-router-dom";
 import { extractPageSlugId, getPageIcon } from "@/lib";
 import { useTranslation } from "react-i18next";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import { usePageMetaQuery } from "@/features/page/queries/page-query.ts";
 import CopyTextButton from "@/components/common/copy.tsx";
 import { getAppUrl } from "@/lib/config.ts";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
@@ -37,7 +37,7 @@ export default function ShareModal({ readOnly }: ShareModalProps) {
   const { t } = useTranslation();
   const { pageSlug } = useParams();
   const pageSlugId = extractPageSlugId(pageSlug);
-  const { data: page } = usePageQuery({ pageId: pageSlugId });
+  const { data: page } = usePageMetaQuery({ pageId: pageSlugId });
   const pageId = page?.id;
   const { data: share } = useShareForPageQuery(pageId);
   const { spaceSlug } = useParams();

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

@@ -38,6 +38,11 @@ export function useGetSpacesQuery(
     queryKey: ["spaces", params],
     queryFn: () => getSpaces(params),
     placeholderData: keepPreviousData,
+    // KEEP refetchOnMount:true (against the global default false): the ["spaces"]
+    // key is invalidated only by same-tab mutations (no socket path), so a
+    // cross-actor change — an admin adding/removing THIS user from a space — has
+    // no local mutation or socket event and would leave the space list stale until
+    // a hard reload. The mount refetch is its only cross-actor freshness path.
     refetchOnMount: true,
   });
 }

apps/client/src/features/space/queries/space-watcher-query.ts

@@ -16,7 +16,6 @@ export function useWatchedSpaceIds(): Set<string> {
   const { data } = useQuery({
     queryKey: [WATCHED_SPACE_IDS_KEY],
     queryFn: () => getWatchedSpaceIds(),
-    refetchOnMount: true,
   });
 
   const items = data?.items;

apps/client/src/features/websocket/use-query-subscription.ts

@@ -19,7 +19,11 @@ export const useQuerySubscription = () => {
   const [socket] = useAtom(socketAtom);
 
   React.useEffect(() => {
-    socket?.on("message", (event) => {
+    if (!socket) return;
+    // Named handler + off() cleanup (mirrors use-notification-socket). Without
+    // cleanup, every socket recreation / effect re-run stacked another listener,
+    // so a single broadcast fired duplicated invalidateQueries / setQueryData.
+    const handleMessage = (event) => {
       const data: WebSocketEvent = event;
 
       let entity = null;
@@ -163,6 +167,11 @@ export const useQuerySubscription = () => {
           });
           break;
       }
-    });
+    };
+
+    socket.on("message", handleMessage);
+    return () => {
+      socket.off("message", handleMessage);
+    };
   }, [queryClient, socket]);
 };

apps/client/src/features/websocket/use-tree-socket.ts

@@ -1,6 +1,6 @@
 import { useEffect } from "react";
 import { socketAtom } from "@/features/websocket/atoms/socket-atom.ts";
-import { useAtom } from "jotai";
+import { useAtom, useSetAtom } from "jotai";
 import { treeDataAtom } from "@/features/page/tree/atoms/tree-data-atom.ts";
 import { WebSocketEvent } from "@/features/websocket/types";
 import { SpaceTreeNode } from "@/features/page/tree/types.ts";
@@ -16,7 +16,10 @@ import localEmitter from "@/lib/local-emitter.ts";
 
 export const useTreeSocket = () => {
   const [socket] = useAtom(socketAtom);
-  const [, setTreeData] = useAtom(treeDataAtom);
+  // Setter-only: this hook writes the tree from socket events but never reads it
+  // reactively, so useSetAtom avoids re-rendering UserProvider (its host) on
+  // every tree event.
+  const setTreeData = useSetAtom(treeDataAtom);
   const queryClient = useQueryClient();
 
   useEffect(() => {
@@ -37,7 +40,11 @@ export const useTreeSocket = () => {
   }, []);
 
   useEffect(() => {
-    socket?.on("message", (event: WebSocketEvent) => {
+    if (!socket) return;
+    // Named handler + off() cleanup (mirrors use-notification-socket). Without
+    // cleanup, every socket recreation / effect re-run stacked another listener,
+    // so a single broadcast fired duplicated tree walks after each reconnect.
+    const handleMessage = (event: WebSocketEvent) => {
       switch (event.operation) {
         case "updateOne":
           if (event.entity[0] === "pages") {
@@ -64,6 +71,11 @@ export const useTreeSocket = () => {
           });
           break;
       }
-    });
-  }, [socket]);
+    };
+
+    socket.on("message", handleMessage);
+    return () => {
+      socket.off("message", handleMessage);
+    };
+  }, [socket, queryClient, setTreeData]);
 };

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

@@ -243,6 +243,5 @@ export function useAppVersion(
     queryFn: () => getAppVersion(),
     staleTime: 60 * 60 * 1000, // 1 hr
     enabled: isEnabled,
-    refetchOnMount: true,
   });
 }

apps/client/src/hooks/use-clipboard.ts

@@ -1,7 +1,7 @@
 // Source: https://github.com/mantinedev/mantine/blob/master/packages/@mantine/hooks/src/use-clipboard/use-clipboard.ts
 // polyfilled to support execCommand fallback
 import { useState } from "react";
-import { execCommandCopy } from "@docmost/editor-ext";
+import { execCommandCopy } from "@/lib/copy-to-clipboard.ts";
 
 export type UseClipboardOptions = {
   timeout?: number;

apps/client/src/lib/config.ts

@@ -1,7 +1,7 @@
 import bytes from "bytes";
 import { castToBoolean } from "@/lib/utils.tsx";
 import { AvatarIconType } from "@/features/attachments/types/attachment.types.ts";
-import { sanitizeUrl } from "@docmost/editor-ext";
+import { sanitizeUrl } from "@/lib/sanitize-url.ts";
 
 declare global {
   interface Window {

apps/client/src/lib/copy-to-clipboard.ts

@@ -0,0 +1,16 @@
+// Client-local execCommand copy fallback (previously imported from
+// @docmost/editor-ext). It lives here so the ubiquitous useClipboard / CopyButton
+// path does not pull in the editor-ext barrel — and with it the whole TipTap
+// engine — through the eager startup graph. Behavior is identical to the
+// editor-ext helper it replaces.
+export function execCommandCopy(text: string): void {
+  const textarea = document.createElement("textarea");
+  textarea.value = text;
+  textarea.style.position = "fixed";
+  textarea.style.left = "-9999px";
+  textarea.style.top = "-9999px";
+  document.body.appendChild(textarea);
+  textarea.select();
+  document.execCommand("copy");
+  document.body.removeChild(textarea);
+}

apps/client/src/lib/sanitize-url.test.ts

@@ -0,0 +1,31 @@
+import { describe, it, expect } from "vitest";
+import { sanitizeUrl } from "./sanitize-url";
+
+// `sanitizeUrl` is a byte-identical client-local copy of editor-ext's wrapper
+// around @braintree/sanitize-url: it maps the sanitizer's "about:blank" XSS
+// sentinel to "". These assertions mirror editor-ext's own security-contract
+// test so the extracted copy keeps the same guarantees.
+describe("sanitizeUrl", () => {
+  it("blocks dangerous schemes (returns empty string)", () => {
+    expect(sanitizeUrl("javascript:alert(1)")).toBe("");
+    expect(sanitizeUrl("data:text/html,<script>alert(1)</script>")).toBe("");
+    expect(sanitizeUrl("vbscript:msgbox(1)")).toBe("");
+    // Case / whitespace obfuscation must not slip past the sanitizer.
+    expect(sanitizeUrl("  JaVaScRiPt:alert(1)")).toBe("");
+  });
+
+  it("returns empty string for empty / undefined input", () => {
+    expect(sanitizeUrl(undefined)).toBe("");
+    expect(sanitizeUrl("")).toBe("");
+  });
+
+  it("allows safe https, relative file and mailto URLs", () => {
+    expect(sanitizeUrl("https://example.com/page")).toMatch(
+      /^https:\/\/example\.com\/page/,
+    );
+    expect(sanitizeUrl("/api/files/abc-123")).toBe("/api/files/abc-123");
+    expect(sanitizeUrl("mailto:user@example.com")).toBe(
+      "mailto:user@example.com",
+    );
+  });
+});

apps/client/src/lib/sanitize-url.ts

@@ -0,0 +1,15 @@
+import { sanitizeUrl as braintreeSanitizeUrl } from "@braintree/sanitize-url";
+
+// Client-local copy of editor-ext's sanitizeUrl wrapper. Importing it from the
+// editor-ext barrel dragged the whole TipTap engine into the eager startup graph
+// via the app-wide config module (getFileUrl). This keeps the exact same
+// behavior (braintree sanitize + normalize "about:blank" -> "") without that
+// dependency.
+export function sanitizeUrl(url: string | undefined): string {
+  if (!url) return "";
+
+  const sanitized = braintreeSanitizeUrl(url);
+
+  // Return an empty string instead of "about:blank".
+  return sanitized === "about:blank" ? "" : sanitized;
+}

apps/client/src/main.tsx

@@ -13,15 +13,14 @@ import { ModalsProvider } from "@mantine/modals";
 import { Notifications } from "@mantine/notifications";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { HelmetProvider } from "react-helmet-async";
+import { ChunkLoadErrorBoundary } from "@/components/chunk-load-error-boundary.tsx";
 import "./i18n";
-import { PostHogProvider } from "posthog-js/react";
 import {
   getPostHogHost,
   getPostHogKey,
   isCloud,
   isPostHogEnabled,
 } from "@/lib/config.ts";
-import posthog from "posthog-js";
 import { initVitals } from "@/lib/telemetry/vitals";
 
 export const queryClient = new QueryClient({
@@ -35,15 +34,6 @@ export const queryClient = new QueryClient({
   },
 });
 
-if (isCloud() && isPostHogEnabled) {
-  posthog.init(getPostHogKey(), {
-    api_host: getPostHogHost(),
-    defaults: "2025-05-24",
-    disable_session_recording: true,
-    capture_pageleave: false,
-  });
-}
-
 // #355 — client perf-telemetry. Decides sampling ONCE (25%/session) before
 // subscribing to any observer; non-sampled sessions send nothing.
 initVitals();
@@ -51,19 +41,62 @@ initVitals();
 const container = document.getElementById("root") as HTMLElement;
 const root = (container as any).__reactRoot ??= ReactDOM.createRoot(container);
 
-root.render(
-  <BrowserRouter>
-    <MantineProvider theme={theme} cssVariablesResolver={mantineCssResolver}>
-      <ModalsProvider>
-        <QueryClientProvider client={queryClient}>
-          <Notifications position="bottom-center" limit={3} zIndex={10000} />
-          <HelmetProvider>
-            <PostHogProvider client={posthog}>
-              <App />
-            </PostHogProvider>
-          </HelmetProvider>
-        </QueryClientProvider>
-      </ModalsProvider>
-    </MantineProvider>
-  </BrowserRouter>,
-);
+function renderApp() {
+  root.render(
+    <BrowserRouter>
+      <MantineProvider theme={theme} cssVariablesResolver={mantineCssResolver}>
+        <ModalsProvider>
+          <QueryClientProvider client={queryClient}>
+            <Notifications position="bottom-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
+                  blanking the whole app. */}
+              <ChunkLoadErrorBoundary>
+                <App />
+              </ChunkLoadErrorBoundary>
+            </HelmetProvider>
+          </QueryClientProvider>
+        </ModalsProvider>
+      </MantineProvider>
+    </BrowserRouter>,
+  );
+}
+
+async function initAnalytics() {
+  // posthog-js is only pulled in for cloud deployments with analytics enabled, so
+  // self-hosted builds never download it. The gate is kept identical to the
+  // previous eager code so cloud analytics behavior is unchanged; the import is
+  // simply deferred behind it.
+  //
+  // Crucially this runs AFTER the immediate first render below, so first paint is
+  // never gated on the analytics chunk. Any failure (network, stale 404, or an
+  // ad-blocker blocking a chunk named "posthog") is swallowed so the user keeps a
+  // working app without analytics instead of a permanently blank page.
+  //
+  // NOTE: we init the posthog SINGLETON only and do NOT wrap the tree in
+  // <PostHogProvider>. The app has zero consumers of the PostHog React context
+  // (no usePostHog / useFeatureFlag* / PostHogFeature), and PostHogProvider given
+  // an already-initialized `client` is a no-op — all capture goes through the
+  // singleton. Re-rendering to attach the provider would only REMOUNT the whole
+  // App (running every mount effect twice and dropping local state / focus /
+  // in-progress input on cloud cold-load) for no functional gain.
+  if (!(isCloud() && isPostHogEnabled)) return;
+  try {
+    const { default: posthog } = await import("posthog-js");
+    posthog.init(getPostHogKey(), {
+      api_host: getPostHogHost(),
+      defaults: "2025-05-24",
+      disable_session_recording: true,
+      capture_pageleave: false,
+    });
+  } catch {
+    // Analytics failed to load — degrade gracefully; the app already rendered.
+  }
+}
+
+// Paint immediately for everyone (self-hosted stays exactly as instant as before,
+// cloud no longer blocks on the analytics import). The posthog singleton is
+// initialized after, without re-rendering the tree.
+renderApp();
+void initAnalytics();

apps/client/src/pages/page/page-redirect.tsx

@@ -1,6 +1,6 @@
 import { useNavigate, useParams } from "react-router-dom";
 import { useEffect } from "react";
-import { usePageQuery } from "@/features/page/queries/page-query";
+import { usePageMetaQuery } from "@/features/page/queries/page-query";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
 import { extractPageSlugId } from "@/lib";
 import { Error404 } from "@/components/ui/error-404.tsx";
@@ -11,7 +11,7 @@ export default function PageRedirect() {
     data: page,
     isLoading: pageIsLoading,
     isError,
-  } = usePageQuery({ pageId: extractPageSlugId(pageSlug) });
+  } = usePageMetaQuery({ pageId: extractPageSlugId(pageSlug) });
   const navigate = useNavigate();
 
   useEffect(() => {

apps/client/src/pages/page/page.tsx

@@ -10,7 +10,7 @@ import { useTranslation } from "react-i18next";
 import React from "react";
 import { EmptyState } from "@/components/ui/empty-state.tsx";
 import { IconAlertTriangle, IconFileOff } from "@tabler/icons-react";
-import { Button } from "@mantine/core";
+import { Button, Skeleton } from "@mantine/core";
 import { Link } from "react-router-dom";
 import { ErrorBoundary } from "react-error-boundary";
 const MemoizedFullEditor = React.memo(FullEditor);
@@ -58,7 +58,7 @@ function PageContent({ pageSlug }: { pageSlug: string | undefined }) {
     (space?.settings?.comments?.allowViewerComments === true);
 
   if (isLoading) {
-    return <></>;
+    return <PageSkeleton />;
   }
 
   if (isError || !page) {
@@ -87,7 +87,7 @@ function PageContent({ pageSlug }: { pageSlug: string | undefined }) {
   }
 
   if (!space) {
-    return <></>;
+    return <PageSkeleton />;
   }
 
   return (
@@ -116,3 +116,18 @@ function PageContent({ pageSlug }: { pageSlug: string | undefined }) {
     )
   );
 }
+
+// Lightweight loading placeholder shown instead of a blank fragment while the
+// page (or its space) is loading, so navigation into a not-yet-cached page no
+// longer flashes empty. Approximates the title + first content lines.
+function PageSkeleton() {
+  return (
+    <div>
+      <Skeleton height={34} width="45%" mt="xl" radius="sm" />
+      <Skeleton height={16} mt="xl" radius="sm" />
+      <Skeleton height={16} mt="sm" radius="sm" />
+      <Skeleton height={16} mt="sm" width="85%" radius="sm" />
+      <Skeleton height={16} mt="sm" width="70%" radius="sm" />
+    </div>
+  );
+}

apps/client/vite.config.ts

@@ -1,5 +1,6 @@
 import { defineConfig, loadEnv } from "vite";
 import react from "@vitejs/plugin-react";
+import { compression } from "vite-plugin-compression2";
 import * as path from "path";
 import { execSync } from "node:child_process";
 
@@ -53,7 +54,25 @@ export default defineConfig(({ mode }) => {
       },
       APP_VERSION: JSON.stringify(resolveAppVersion(envPath)),
     },
-    plugins: [react()],
+    plugins: [
+      react(),
+      // 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({
+        algorithms: ["brotliCompress", "gzip"],
+        // vite-plugin-compression2's default `include` only covers text-ish
+        // bundle output (js/mjs/json/css/html/svg/…). Extend it with the large
+        // VAD binaries copied from public/vad (.wasm ~26MB, .onnx ~2.3MB) so
+        // they are brotli/gzip'd once at build time and served via
+        // @fastify/static preCompressed — otherwise @fastify/compress would
+        // re-brotli them on EVERY request. The default types are repeated here
+        // because setting `include` replaces (does not extend) the default.
+        include: /\.(html|xml|css|json|js|mjs|svg|yaml|yml|toml|wasm|onnx)$/,
+        // index.html is rewritten at server boot (window.CONFIG injection); a
+        // precompressed copy would go stale — NEVER precompress it.
+        exclude: [/index\.html$/],
+      }),
+    ],
     build: {
       rolldownOptions: {
         output: {
@@ -63,6 +82,20 @@ export default defineConfig(({ mode }) => {
                 name: "vendor-mantine",
                 test: /[\\/]node_modules[\\/]@mantine[\\/]/,
               },
+              // NOTE: TipTap/ProseMirror/Yjs are intentionally NOT force-grouped
+              // into a single vendor chunk. Doing so backfires: rolldown co-locates
+              // a small module shared with the (eager) react-i18next runtime into
+              // that group chunk, which then drags the whole ~590KB editor engine
+              // into the eager modulepreload graph. Left to the default splitting,
+              // the editor engine stays in lazily-loaded chunks pulled only by the
+              // route-split editor/share pages. KaTeX is safe to group (nothing
+              // eager references it).
+              // KaTeX in its own stable chunk; loaded on demand by the lazy math
+              // node views (never in the startup path).
+              {
+                name: "vendor-katex",
+                test: /[\\/]node_modules[\\/]katex[\\/]/,
+              },
             ],
           },
         },

apps/server/package.json

@@ -44,6 +44,7 @@
     "@docmost/mcp": "workspace:*",
     "@docmost/pdf-inspector": "1.9.6",
     "@docmost/prosemirror-markdown": "workspace:*",
+    "@fastify/compress": "^9.0.0",
     "@fastify/cookie": "^11.0.2",
     "@fastify/multipart": "^10.0.0",
     "@fastify/static": "^9.1.3",

apps/server/src/collaboration/constants.ts

@@ -1,3 +1,10 @@
 export const HISTORY_INTERVAL = 5 * 60 * 1000;
 export const HISTORY_FAST_INTERVAL = 60 * 1000;
 export const HISTORY_FAST_THRESHOLD = 5 * 60 * 1000;
+
+// #348 — debounce window for the per-page RAG re-embed job. Repeated saves
+// within this window collapse to a single delayed job (coalesced by a stable
+// jobId), so active editing does not pile up expensive re-embeds (external API
+// + page_embeddings rewrite, concurrency 1). The worker reads the CURRENT page
+// state at run time, so the last content within the window wins.
+export const EMBED_DEBOUNCE_MS = 30 * 1000;

apps/server/src/collaboration/extensions/hocuspocus-unload-race.spec.ts

@@ -0,0 +1,140 @@
+/**
+ * gitmost #401 — regression test for the connect-vs-unload race in
+ * @hocuspocus/server 3.4.4 (patched via patches/@hocuspocus__server@3.4.4.patch).
+ *
+ * The race (unpatched): when the last client disconnects, storeDocumentHooks'
+ * `finally` schedules an async `unloadDocument`. That unload runs its
+ * `beforeUnloadDocument` hooks asynchronously and, meanwhile, records an
+ * in-flight promise in `this.unloadingDocuments`. In the original 3.4.4
+ * `createDocument`, a NEW connection arriving in that window falls straight
+ * through to the `loadingDocuments`/`documents` checks — it never consults
+ * `unloadingDocuments`. So the new connection can start loading (or reuse) a
+ * document while the old instance is still being torn down; the re-check inside
+ * unload (`shouldUnloadDocument`, which sees 0 connections because async auth
+ * hooks have not registered the new connection yet) then deletes/destroys the
+ * doc out from under the freshly-connected client → orphaned Document → later
+ * redis-sync takes the "doc not loaded" path → sync never completes → the
+ * provider hangs until its ~25s timeout.
+ *
+ * The patch: `createDocument` first awaits any in-flight
+ * `unloadingDocuments.get(name)` before proceeding. Once that settles, the
+ * decision is deterministic — either the doc was fully unloaded (gone from
+ * `documents`, so a clean fresh load) or the unload aborted (healthy doc still
+ * in `documents`, reused). The new connection can never hand-shake onto an
+ * about-to-be-destroyed Document.
+ *
+ * These tests exercise the REAL patched `Hocuspocus.createDocument` (the class
+ * is directly constructible) by seeding `unloadingDocuments` with a controllable
+ * in-flight unload and observing that createDocument waits for it.
+ */
+import { Hocuspocus } from '@hocuspocus/server';
+
+// A promise we can resolve on demand, to model an unload that is mid-flight.
+function deferred<T = void>() {
+  let resolve!: (v: T) => void;
+  const promise = new Promise<T>((r) => {
+    resolve = r;
+  });
+  return { promise, resolve };
+}
+
+describe('gitmost #401 — hocuspocus createDocument awaits in-flight unload', () => {
+  it('does NOT start loading a new doc until the in-flight unload settles, then loads fresh', async () => {
+    const hp = new Hocuspocus();
+    const name = 'page.race';
+
+    // Observe loadDocument: on the unpatched code it is invoked synchronously
+    // within createDocument (before the unload settles); on the patched code it
+    // must be deferred until unloadingDocuments resolves.
+    const freshDoc = { name, __fresh: true } as any;
+    const loadSpy = jest
+      .spyOn(hp as any, 'loadDocument')
+      .mockResolvedValue(freshDoc);
+
+    // Model an unload in progress: an entry sits in unloadingDocuments and, when
+    // it completes, it removes the doc from `documents` (a real full unload).
+    const unload = deferred();
+    (hp as any).documents.set(name, { name, __dying: true });
+    (hp as any).unloadingDocuments.set(
+      name,
+      unload.promise.then(() => {
+        (hp as any).documents.delete(name);
+      }),
+    );
+
+    // Kick off a new connection's createDocument but do not await it yet.
+    const createPromise = (hp as any).createDocument(
+      name,
+      {},
+      'socket-1',
+      { isAuthenticated: true, readOnly: false },
+      {},
+    );
+
+    // Let all currently-schedulable microtasks run. The patched createDocument is
+    // now parked on `await unloadingDocuments.get(name)`, so loadDocument must
+    // NOT have been called yet, and it must NOT have returned the dying doc.
+    await Promise.resolve();
+    await Promise.resolve();
+    expect(loadSpy).not.toHaveBeenCalled();
+
+    // The unload completes (doc removed from `documents`).
+    unload.resolve();
+
+    // createDocument now proceeds: sees no existing doc → fresh load.
+    const doc = await createPromise;
+    expect(loadSpy).toHaveBeenCalledTimes(1);
+    expect(doc).toBe(freshDoc);
+    // The freshly-loaded doc is the one registered — never the dying instance.
+    expect((hp as any).documents.get(name)).toBe(freshDoc);
+  });
+
+  it('reuses the live doc when the in-flight unload aborts (doc left in documents)', async () => {
+    const hp = new Hocuspocus();
+    const name = 'page.abort';
+
+    const loadSpy = jest.spyOn(hp as any, 'loadDocument');
+
+    // Model an unload that ABORTS (e.g. a new connection reappeared before the
+    // sync re-check): it settles WITHOUT deleting the doc from `documents`.
+    const unload = deferred();
+    const liveDoc = { name, __live: true } as any;
+    (hp as any).documents.set(name, liveDoc);
+    (hp as any).unloadingDocuments.set(name, unload.promise); // no-op unload
+
+    const createPromise = (hp as any).createDocument(
+      name,
+      {},
+      'socket-2',
+      { isAuthenticated: true, readOnly: false },
+      {},
+    );
+
+    unload.resolve();
+    const doc = await createPromise;
+
+    // The still-present live doc is reused; no fresh load happened.
+    expect(doc).toBe(liveDoc);
+    expect(loadSpy).not.toHaveBeenCalled();
+  });
+
+  it('no in-flight unload → behaves normally (fresh load)', async () => {
+    const hp = new Hocuspocus();
+    const name = 'page.normal';
+    const freshDoc = { name } as any;
+    const loadSpy = jest
+      .spyOn(hp as any, 'loadDocument')
+      .mockResolvedValue(freshDoc);
+
+    const doc = await (hp as any).createDocument(
+      name,
+      {},
+      'socket-3',
+      { isAuthenticated: true, readOnly: false },
+      {},
+    );
+
+    expect(loadSpy).toHaveBeenCalledTimes(1);
+    expect(doc).toBe(freshDoc);
+  });
+});

apps/server/src/collaboration/extensions/persistence-load.spec.ts

@@ -0,0 +1,130 @@
+/**
+ * gitmost #401 fix 2 — onLoadDocument applies the DB state directly into the
+ * hook's target document and returns undefined (instead of building a NEW Y.Doc
+ * and returning it, which made hocuspocus re-encode+apply the whole state a
+ * SECOND time on every cold load).
+ *
+ * These tests assert:
+ *  - the hook mutates `data.document` in place so its content equals the DB doc,
+ *  - onLoadDocument returns undefined (so hocuspocus keeps the mutated doc and
+ *    does NOT run its own applyUpdate(encodeStateAsUpdate(...)) merge),
+ *  - both the raw-ydoc branch and the json→ydoc conversion branch behave so.
+ *
+ * Returning undefined is the observable signal that the double-encode is gone
+ * (the old code returned a new Y.Doc, which made hocuspocus re-encode+apply the
+ * state a second time); we assert that contract rather than counting internal
+ * encode calls, which is brittle given the encodes inside toYdoc and the test's
+ * own `expected` fixtures.
+ */
+import * as Y from 'yjs';
+import { Document } from '@hocuspocus/server';
+import { TiptapTransformer } from '@hocuspocus/transformer';
+import { PersistenceExtension } from './persistence.extension';
+import { tiptapExtensions } from '../collaboration.util';
+
+// A fresh hocuspocus Document (extends Y.Doc, adds isEmpty()) as hocuspocus
+// hands to onLoadDocument on a cold load.
+const freshDoc = () => new Document(`page.${PAGE_ID}`, {});
+
+const PAGE_ID = '550e8400-e29b-41d4-a716-446655440000';
+
+const doc = (text: string) => ({
+  type: 'doc',
+  content: [{ type: 'paragraph', content: [{ type: 'text', text }] }],
+});
+
+const jsonOf = (ydoc: Y.Doc) =>
+  TiptapTransformer.fromYdoc(ydoc, 'default');
+
+describe('PersistenceExtension.onLoadDocument — #401 fix 2 (apply-into-hook-doc)', () => {
+  let ext: PersistenceExtension;
+  let pageRepo: { findById: jest.Mock };
+
+  beforeEach(() => {
+    pageRepo = { findById: jest.fn() };
+    ext = new PersistenceExtension(
+      pageRepo as any,
+      {} as any,
+      {} as any,
+      {} as any,
+      {} as any,
+      {} as any,
+      {} as any,
+      {} as any,
+    );
+    jest.spyOn(ext['logger'], 'debug').mockImplementation(() => undefined);
+    jest.spyOn(ext['logger'], 'warn').mockImplementation(() => undefined);
+  });
+
+  const load = (document: Document) =>
+    ext.onLoadDocument({ documentName: `page.${PAGE_ID}`, document } as any);
+
+  it('raw ydoc branch: mutates the hook doc to the DB state and returns undefined', async () => {
+    // Source doc representing the persisted ydoc state.
+    const source = TiptapTransformer.toYdoc(
+      doc('DB CONTENT'),
+      'default',
+      tiptapExtensions,
+    );
+    const dbState = Buffer.from(Y.encodeStateAsUpdate(source));
+    pageRepo.findById.mockResolvedValue({ id: PAGE_ID, ydoc: dbState });
+
+    // The hook target is a fresh empty doc (as hocuspocus supplies on cold load).
+    const target = freshDoc();
+    const result = await load(target);
+
+    // Return undefined so hocuspocus keeps `target` as-is (no second merge).
+    expect(result).toBeUndefined();
+    // The hook document now carries the DB content.
+    expect(jsonOf(target)).toEqual(jsonOf(source));
+  });
+
+  it('json→ydoc branch: converts page.content into the hook doc and returns undefined', async () => {
+    pageRepo.findById.mockResolvedValue({
+      id: PAGE_ID,
+      ydoc: null,
+      content: doc('JSON CONTENT'),
+    });
+
+    const target = freshDoc();
+    const result = await load(target);
+
+    // Returning undefined is what keeps hocuspocus from re-encoding+applying the
+    // state a second time (the old code returned the doc, forcing that extra
+    // encode). We assert the observable contract here — the return value and the
+    // resulting content — rather than counting internal encode calls, which is
+    // brittle: toYdoc and the `expected` build below both encode too.
+    expect(result).toBeUndefined();
+
+    // The converted content landed in the hook document.
+    const expected = TiptapTransformer.toYdoc(
+      doc('JSON CONTENT'),
+      'default',
+      tiptapExtensions,
+    );
+    expect(jsonOf(target)).toEqual(jsonOf(expected));
+  });
+
+  it('live doc already non-empty: early return, no DB read', async () => {
+    // A hocuspocus Document carrying live content (isEmpty('default') === false).
+    const target = freshDoc();
+    const live = TiptapTransformer.toYdoc(
+      doc('LIVE'),
+      'default',
+      tiptapExtensions,
+    );
+    Y.applyUpdate(target, Y.encodeStateAsUpdate(live));
+
+    const result = await load(target);
+    expect(result).toBeUndefined();
+    expect(pageRepo.findById).not.toHaveBeenCalled();
+  });
+
+  it('no persisted state: leaves the fresh empty doc untouched, returns undefined', async () => {
+    pageRepo.findById.mockResolvedValue({ id: PAGE_ID, ydoc: null, content: null });
+    const target = freshDoc();
+    const result = await load(target);
+    expect(result).toBeUndefined();
+    expect(target.isEmpty('default')).toBe(true);
+  });
+});

apps/server/src/collaboration/extensions/persistence-store.spec.ts

@@ -431,7 +431,17 @@ describe('PersistenceExtension.onStoreDocument — Approach-A boundary snapshot'
   it('uses the canonical page.id (not the slugId doc name) for post-store side effects (#260)', async () => {
     const SLUG = 'slug-1'; // persistedHumanPage.slugId; findById resolves it
     const document = ydocFor(doc('NEW AGENT CONTENT'));
-    pageRepo.findById.mockResolvedValue(persistedHumanPage('NEW AGENT CONTENT'));
+    // #348 — the transclusion sync now runs only when the new OR the previously
+    // persisted content carries a transclusion-family node. Give the persisted
+    // (old) content a pageEmbed so the sync path is exercised and the #260
+    // UUID-vs-slugId contract asserted below is still verified.
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('NEW AGENT CONTENT'),
+      content: {
+        type: 'doc',
+        content: [{ type: 'pageEmbed', attrs: { sourcePageId: 'src-1' } }],
+      },
+    });
     pageHistoryRepo.findPageLastHistory.mockResolvedValue(null);
 
     // A `page.<slugId>` document name (the bug's smoking gun), agent store over

apps/server/src/collaboration/extensions/persistence.extension.ts

@@ -36,6 +36,7 @@ import {
 import { Page } from '@docmost/db/types/entity.types';
 import { CollabHistoryService } from '../services/collab-history.service';
 import {
+  EMBED_DEBOUNCE_MS,
   HISTORY_FAST_INTERVAL,
   HISTORY_FAST_THRESHOLD,
   HISTORY_INTERVAL,
@@ -45,6 +46,7 @@ import {
   observeCollabLoad,
   observeCollabStore,
 } from '../../integrations/metrics/metrics.registry';
+import { hasTransclusionFamilyNodes } from '../../core/page/transclusion/utils/transclusion-prosemirror.util';
 
 /**
  * #251 — wire format of the client→server stateless message that signals a
@@ -171,15 +173,21 @@ export class PersistenceExtension implements Extension {
       return;
     }
 
+    // #401 fix 2 — apply the DB state DIRECTLY into the hook's target document
+    // (`document` === `data.document`) and return undefined. When onLoadDocument
+    // returns undefined, hocuspocus keeps the mutated hook document as-is; only
+    // when the hook RETURNS a Y.Doc does hocuspocus re-`applyUpdate(document,
+    // encodeStateAsUpdate(returned))` — a second full encode+apply of the whole
+    // (e.g. 315KB) state on every cold load. Mutating in place performs a single
+    // apply and avoids the throwaway `new Y.Doc()` allocation.
     if (page.ydoc) {
       this.logger.debug(`ydoc loaded from db: ${pageId}`);
 
-      const doc = new Y.Doc();
       const dbState = new Uint8Array(page.ydoc);
 
-      Y.applyUpdate(doc, dbState);
+      Y.applyUpdate(document, dbState);
       observeCollabLoad(dbState.length, (performance.now() - startedAt) / 1000);
-      return doc;
+      return;
     }
 
     // if no ydoc state in db convert json in page.content to Ydoc.
@@ -192,18 +200,23 @@ export class PersistenceExtension implements Extension {
         tiptapExtensions,
       );
 
-      // Reuse this single encode for the size label (do NOT add a second one).
+      // Encode the converted doc ONCE, reuse the bytes for both the size label
+      // and the single apply into the hook document (previously this encode's
+      // result was returned and hocuspocus re-encoded+applied it a second time).
       const encoded = Y.encodeStateAsUpdate(ydoc);
+      Y.applyUpdate(document, encoded);
       observeCollabLoad(
         encoded.byteLength,
         (performance.now() - startedAt) / 1000,
       );
-      return ydoc;
+      return;
     }
 
+    // No persisted state: the hook document is already a fresh empty Y.Doc, so
+    // leave it untouched and return undefined (no re-encode of an empty doc).
     this.logger.debug(`creating fresh ydoc: ${pageId}`);
     observeCollabLoad(0, (performance.now() - startedAt) / 1000);
-    return new Y.Doc();
+    return;
   }
 
   async onStoreDocument(data: onStoreDocumentPayload) {
@@ -439,7 +452,18 @@ export class PersistenceExtension implements Extension {
       // Use the canonical page UUID (page.id), not the doc-name id, which may be
       // a slugId for a `page.<slugId>` doc (#260). The transclusion/reference
       // syncs write uuid-typed columns, so a slugId here threw Postgres 22P02.
-      await this.syncTransclusion(page.id, page.workspaceId, tiptapJson);
+      //
+      // #348 — skip the three sync SELECTs when neither the new content nor the
+      // previously-persisted content has any transclusion/reference/pageEmbed
+      // node: nothing to insert, and (the DB mirrors the old content) nothing to
+      // delete. Whenever either side has one, run the idempotent sync exactly as
+      // before so removals are still reconciled.
+      if (
+        hasTransclusionFamilyNodes(tiptapJson) ||
+        hasTransclusionFamilyNodes(page.content)
+      ) {
+        await this.syncTransclusion(page.id, page.workspaceId, tiptapJson);
+      }
     }
 
     if (page) {
@@ -455,7 +479,17 @@ export class PersistenceExtension implements Extension {
         (m) => m.entityId,
       );
 
-      if (userMentions.length > 0) {
+      // #348 — only enqueue when the mentioned-user set actually GAINED a member.
+      // The processor (processPageMention) already no-ops when every current
+      // mention was present before (newMentions.length === 0), so skipping the
+      // enqueue in that case is behavior-identical and avoids piling up no-op jobs
+      // on every save of a page that merely CONTAINS (unchanged) mentions.
+      const oldMentionedUserIdSet = new Set(oldMentionedUserIds);
+      const hasNewMentionedUser = userMentions.some(
+        (m) => !oldMentionedUserIdSet.has(m.entityId),
+      );
+
+      if (hasNewMentionedUser) {
         await this.notificationQueue.add(QueueJob.PAGE_MENTION_NOTIFICATION, {
           userMentions: userMentions.map((m) => ({
             userId: m.entityId,
@@ -470,12 +504,23 @@ export class PersistenceExtension implements Extension {
         } as IPageMentionNotificationJob);
       }
 
-      await this.aiQueue.add(QueueJob.PAGE_CONTENT_UPDATED, {
-        // Canonical UUID: the embedding reindex resolves pages by uuid, so a
-        // slugId here threw Postgres 22P02 invalid-uuid (#260).
-        pageIds: [page.id],
-        workspaceId: page.workspaceId,
-      });
+      await this.aiQueue.add(
+        QueueJob.PAGE_CONTENT_UPDATED,
+        {
+          // Canonical UUID: the embedding reindex resolves pages by uuid, so a
+          // slugId here threw Postgres 22P02 invalid-uuid (#260).
+          pageIds: [page.id],
+          workspaceId: page.workspaceId,
+        },
+        // #348 — coalesce re-embeds during active editing. A stable per-page
+        // jobId + delay means repeated saves within EMBED_DEBOUNCE_MS collapse
+        // to one delayed job instead of one expensive re-embed per save. The
+        // worker reads the current page state at run time, so last content wins.
+        // BullMQ forbids ':' in custom job ids (Redis key separator), so '-' is
+        // used; page.id is a UUID, so the id is unique per page. removeOnComplete
+        // (queue.module) frees the id after each run so the next window re-arms.
+        { jobId: `embed-${page.id}`, delay: EMBED_DEBOUNCE_MS },
+      );
 
       await this.enqueuePageHistory(page, lastUpdatedSource);
     }

apps/server/src/collaboration/extensions/redis-sync/redis-sync.extension.ts

@@ -220,6 +220,13 @@ export class RedisSyncExtension<TCE extends CustomEvents> implements Extension {
   };
 
   async maintainLock(documentName: string) {
+    // #348 — clear any existing timer for this document before installing a new
+    // one. Without this, a second maintainLock for the same document (a
+    // reload-without-unload) overwrites this.locks[documentName] and leaks the
+    // previous interval, which keeps firing SET forever with no way to clear it.
+    if (this.locks[documentName]) {
+      clearInterval(this.locks[documentName]);
+    }
     this.locks[documentName] = setInterval(() => {
       this.pub.set(
         this.getKey(documentName),

apps/server/src/common/helpers/cache-keys.ts

@@ -4,8 +4,21 @@ export const CacheKey = {
     `perm:space-roles:${userId}:${spaceId}`,
   PAGE_CAN_EDIT: (userId: string, pageId: string) =>
     `perm:can-edit:${userId}:${pageId}`,
+  // #348 — DomainMiddleware workspace resolution. Self-hosted resolves the single
+  // workspace (constant key); cloud resolves by the request subdomain (lowercased
+  // to match the case-insensitive `LOWER(hostname)` lookup). Every WorkspaceRepo
+  // mutator busts these, so staleness is bounded by both explicit invalidation and
+  // the short TTL below.
+  WORKSPACE_SELF_HOSTED: 'workspace:self-hosted',
+  WORKSPACE_BY_HOST: (subdomain: string) =>
+    `workspace:byhost:${subdomain.toLowerCase()}`,
 };
 
 // Permission caches dedupe repeated checks within and across short request bursts.
 // 5s keeps staleness on revocations bounded.
 export const PERMISSION_CACHE_TTL_MS = 5_000;
+
+// #348 — workspace row changes rarely; a short TTL bounds staleness of
+// security-relevant fields (enforceSso/enforceMfa/status) even if an explicit
+// bust is ever missed, while still removing the per-request workspace query.
+export const WORKSPACE_CACHE_TTL_MS = 15_000;

apps/server/src/common/middlewares/domain.middleware.ts

@@ -1,13 +1,42 @@
-import { Injectable, NestMiddleware, NotFoundException } from '@nestjs/common';
+import { Inject, Injectable, NestMiddleware } from '@nestjs/common';
 import { FastifyRequest, FastifyReply } from 'fastify';
+import { CACHE_MANAGER } from '@nestjs/cache-manager';
+import { Cache } from 'cache-manager';
 import { EnvironmentService } from '../../integrations/environment/environment.service';
 import { WorkspaceRepo } from '@docmost/db/repos/workspace/workspace.repo';
+import { Workspace } from '@docmost/db/types/entity.types';
+import { withCache } from '../helpers/with-cache';
+import { CacheKey, WORKSPACE_CACHE_TTL_MS } from '../helpers/cache-keys';
+
+// #348 — timestamptz columns on the workspace row. The cache store (Keyv/Redis)
+// JSON-serializes values, so a cached workspace comes back with these fields as
+// ISO strings. Reviving them to Date keeps the cached path byte-identical to the
+// direct DB path (postgres.js returns Date), so nothing downstream can observe a
+// cache hit vs miss. Idempotent: `new Date(date)` on an already-Date value is a
+// no-op-equivalent. Keep in sync with the workspace timestamptz columns.
+const WORKSPACE_DATE_FIELDS: Array<keyof Workspace> = [
+  'createdAt',
+  'updatedAt',
+  'deletedAt',
+  'trialEndAt',
+];
+
+function reviveWorkspaceDates(workspace: Workspace): Workspace {
+  for (const field of WORKSPACE_DATE_FIELDS) {
+    const value = workspace[field];
+    if (value != null) {
+      (workspace as any)[field] = new Date(value as any);
+    }
+  }
+  return workspace;
+}
 
 @Injectable()
 export class DomainMiddleware implements NestMiddleware {
   constructor(
     private workspaceRepo: WorkspaceRepo,
     private environmentService: EnvironmentService,
+    @Inject(CACHE_MANAGER) private readonly cacheManager: Cache,
   ) {}
   async use(
     req: FastifyRequest['raw'],
@@ -15,13 +44,21 @@ export class DomainMiddleware implements NestMiddleware {
     next: () => void,
   ) {
     if (this.environmentService.isSelfHosted()) {
-      const workspace = await this.workspaceRepo.findFirst();
+      // #348 — cache the single-workspace lookup that runs on every request.
+      // Invalidated by every WorkspaceRepo mutator (see bustWorkspaceCache).
+      const workspace = await withCache(
+        this.cacheManager,
+        CacheKey.WORKSPACE_SELF_HOSTED,
+        WORKSPACE_CACHE_TTL_MS,
+        () => this.workspaceRepo.findFirst(),
+      );
       if (!workspace) {
         //throw new NotFoundException('Workspace not found');
         (req as any).workspaceId = null;
         return next();
       }
 
+      reviveWorkspaceDates(workspace);
       // TODO: unify
       (req as any).workspaceId = workspace.id;
       (req as any).workspace = workspace;
@@ -29,13 +66,21 @@ export class DomainMiddleware implements NestMiddleware {
       const header = req.headers.host;
       const subdomain = header.split('.')[0];
 
-      const workspace = await this.workspaceRepo.findByHostname(subdomain);
+      // #348 — cache per-subdomain workspace resolution. Keyed by subdomain (the
+      // hostname column); busted per hostname by every WorkspaceRepo mutator.
+      const workspace = await withCache(
+        this.cacheManager,
+        CacheKey.WORKSPACE_BY_HOST(subdomain),
+        WORKSPACE_CACHE_TTL_MS,
+        () => this.workspaceRepo.findByHostname(subdomain),
+      );
 
       if (!workspace) {
         (req as any).workspaceId = null;
         return next();
       }
 
+      reviveWorkspaceDates(workspace);
       (req as any).workspaceId = workspace.id;
       (req as any).workspace = workspace;
     }

apps/server/src/core/ai-chat/ai-chat-stream-registry.service.ts

@@ -17,10 +17,24 @@ import { Injectable, Logger, OnModuleDestroy } from '@nestjs/common';
 /** How long a finished entry is retained for late attach (replay + immediate end). */
 export const RUN_STREAM_RETAIN_FINISHED_MS = 30_000;
 
-/** Per-run replay buffer cap. Past this the buffer is dropped (attach -> 204). */
-export const RUN_STREAM_MAX_BUFFER_BYTES = 4 * 1024 * 1024;
+/**
+ * Per-run replay buffer cap. Past this the buffer is dropped (attach -> 204, and
+ * the client falls back to its restore + degraded-poll path, #430).
+ *
+ * Raised from 4MB to 32MB (#430): marathon autonomous runs (11-25 min observed)
+ * stream far more than 4MB of SSE frames, so a live disconnect mid-run would find
+ * an already-overflowed buffer and could only degrade-poll instead of re-attaching
+ * to the live tail. 32MB comfortably covers those runs while staying bounded.
+ *
+ * Memory cost: this is the WORST-CASE retained size PER ACTIVE run (the buffer is
+ * freed on finish + retention, or dropped immediately on overflow). With the small
+ * number of concurrent autonomous runs a single workspace realistically has, 32MB
+ * each is an acceptable ceiling; the overflow->204->degraded-poll fallback remains
+ * the backstop for anything larger, so correctness never depends on this bound.
+ */
+export const RUN_STREAM_MAX_BUFFER_BYTES = 32 * 1024 * 1024;
 
-// 2x the replay cap: a just-written 4MB replay burst alone can never trip the
+// 2x the replay cap: a just-written full-replay burst alone can never trip the
 // per-subscriber cap (see controller); only a genuinely stalled socket can.
 export const SUBSCRIBER_MAX_BUFFERED_BYTES = 2 * RUN_STREAM_MAX_BUFFER_BYTES;
 

apps/server/src/core/ai-chat/ai-chat-stream-registry.spec.ts

@@ -2,6 +2,7 @@ import {
   AiChatStreamRegistryService,
   RUN_STREAM_MAX_BUFFER_BYTES,
   RUN_STREAM_RETAIN_FINISHED_MS,
+  SUBSCRIBER_MAX_BUFFERED_BYTES,
   RunStreamCallbacks,
 } from './ai-chat-stream-registry.service';
 
@@ -210,9 +211,10 @@ describe('AiChatStreamRegistryService', () => {
     const att = (await registry.attach(CHAT, false, undefined, c.cb))!;
     att.start();
 
-    const oneMb = 'x'.repeat(1024 * 1024);
-    // 5 x 1MB = 5MB > 4MB cap; the 5th frame is the one that crosses.
-    for (let i = 0; i < 5; i++) src.push(oneMb + i);
+    // Cap-relative so it survives a buffer-cap change (#430): a quarter-cap frame
+    // means 5 frames comfortably exceed the replay cap; the last one crosses.
+    const chunk = 'x'.repeat(Math.floor(RUN_STREAM_MAX_BUFFER_BYTES / 4));
+    for (let i = 0; i < 5; i++) src.push(chunk + i);
     await flush();
 
     const entry = (registry as any).entries.get(CHAT);
@@ -220,7 +222,7 @@ describe('AiChatStreamRegistryService', () => {
     expect(entry.bytes).toBeGreaterThan(RUN_STREAM_MAX_BUFFER_BYTES);
     // The live subscriber received ALL 5 frames, including the crossing one.
     expect(c.frames).toHaveLength(5);
-    expect(c.frames[4]).toBe(oneMb + 4);
+    expect(c.frames[4]).toBe(chunk + 4);
 
     // A NEW attach after overflow gets null (replay buffer is gone).
     const c2 = collector();
@@ -240,9 +242,11 @@ describe('AiChatStreamRegistryService', () => {
     const attB = (await registry.attach(CHAT, false, undefined, b.cb))!;
     attB.start();
 
-    const oneMb = 'x'.repeat(1024 * 1024);
-    // 9 x 1MB = 9MB > 8MB per-subscriber cap; A's pending overflows, B streams live.
-    for (let i = 0; i < 9; i++) src.push(oneMb + i);
+    // Cap-relative so it survives a buffer-cap change (#430): a quarter-of-the-
+    // per-subscriber-cap frame means 5 frames exceed A's paused-pending cap while
+    // B streams every frame live.
+    const chunk = 'x'.repeat(Math.floor(SUBSCRIBER_MAX_BUFFERED_BYTES / 4));
+    for (let i = 0; i < 5; i++) src.push(chunk + i);
     await flush();
 
     const entry = (registry as any).entries.get(CHAT);
@@ -250,7 +254,7 @@ describe('AiChatStreamRegistryService', () => {
     expect(entry.subscribers.size).toBe(1);
     expect(a.frames).toEqual([]); // paused + overflowed: nothing was delivered
     // B received every frame live (delivery unaffected by A's overflow).
-    expect(b.frames).toHaveLength(9);
+    expect(b.frames).toHaveLength(5);
 
     // A's start() (arriving late) degrades to an immediate end, not a partial replay.
     attA.start();

apps/server/src/core/ai-chat/ai-chat.prompt.spec.ts

@@ -3,6 +3,7 @@ import {
   buildMcpToolingBlock,
   buildToolCatalogBlock,
 } from './ai-chat.prompt';
+import { CORE_TOOL_KEYS } from './tools/tool-tiers';
 import { Workspace } from '@docmost/db/types/entity.types';
 
 /**
@@ -464,6 +465,19 @@ describe('buildToolCatalogBlock (#332)', () => {
     expect(block).toContain('- transformPage — run a JS transform.');
     expect(block).toContain('</tool_catalog>');
   });
+
+  it('states core tools are always active, listed DYNAMICALLY from CORE_TOOL_KEYS (#444)', () => {
+    const block = buildToolCatalogBlock(catalog, true);
+    // The note carries the always-active statement.
+    expect(block).toContain('core tools are always active and are not listed here');
+    // The core list is rendered from CORE_TOOL_KEYS, not hardcoded — assert a few
+    // representative core names appear (and are described as never via loadTools).
+    expect(block).toContain('ALWAYS active');
+    expect(block).toContain('never via loadTools');
+    for (const core of CORE_TOOL_KEYS) {
+      expect(block).toContain(core);
+    }
+  });
 });
 
 describe('buildSystemPrompt <tool_catalog> gating (#332)', () => {

apps/server/src/core/ai-chat/ai-chat.prompt.tool-names.spec.ts

@@ -0,0 +1,125 @@
+import { readFileSync } from 'node:fs';
+import { join } from 'node:path';
+import { PROMPT_TOOL_NAMES } from './ai-chat.prompt';
+// The real shared registry, imported from source (same approach as the
+// SHARED_TOOL_SPECS contract spec) so tool names are validated against exactly
+// what @docmost/mcp ships.
+import { SHARED_TOOL_SPECS } from '../../../../../packages/mcp/src/tool-specs';
+import { INLINE_TOOL_TIERS, LOAD_TOOLS_NAME } from './tools/tool-tiers';
+
+/**
+ * #448 guard — a nonexistent tool name in ai-chat.prompt.ts must fail a test.
+ *
+ * The in-app prompt refers to a handful of tools BY NAME in its guidance notes
+ * (e.g. PAGE_CHANGED_NOTE tells the agent to re-read via getPage and edit via
+ * editPageText/patchNode/insertNode/deleteNode). Before #448 those names were
+ * hard-coded inline with NO guard, so renaming a tool left the agent stale
+ * instructions and nothing failed.
+ *
+ * APPROACH — substitution + a precise source scan:
+ *  1. The names now flow through the exported `PROMPT_TOOL_NAMES` const; this
+ *     test asserts every value there is a REAL in-app tool.
+ *  2. A precise scan of the two guidance-note string literals in the source
+ *     catches any BARE tool-name token added directly (bypassing the const):
+ *     every camelCase token in those notes must be either a real tool name or an
+ *     explicitly-allowlisted ordinary English/camelCase word.
+ *
+ * The scan is deliberately narrow (only the guidance notes, only camelCase
+ * tokens) so it never false-positives on prose, and the allowlist of non-tool
+ * words is tiny and explicit.
+ */
+
+// The authoritative set of real in-app tool names: shared-registry inAppKeys +
+// per-layer INLINE tool keys + the loadTools meta-tool.
+const VALID_TOOL_NAMES = new Set<string>([
+  ...Object.values(SHARED_TOOL_SPECS).map((s) => s.inAppKey),
+  ...Object.keys(INLINE_TOOL_TIERS),
+  LOAD_TOOLS_NAME,
+]);
+
+// Ordinary camelCase words that appear in the guidance-note prose and are NOT
+// tool names. Keep this list minimal and explicit — anything camelCase in a note
+// that is neither a real tool nor here fails the scan.
+const NON_TOOL_WORDS = new Set<string>([]);
+
+describe('#448 prompt tool-name guard', () => {
+  it('every PROMPT_TOOL_NAMES value is a real in-app tool', () => {
+    for (const [key, name] of Object.entries(PROMPT_TOOL_NAMES)) {
+      expect(typeof name).toBe('string');
+      expect(VALID_TOOL_NAMES.has(name)).toBe(true);
+      // Sanity: the const key and its value are the same token (the const is a
+      // name->name map used purely to route mentions through one guarded place).
+      expect(key).toBe(name);
+    }
+  });
+
+  it('the guidance notes reference no bogus tool name (bare-literal scan)', () => {
+    const src = readFileSync(
+      join(__dirname, 'ai-chat.prompt.ts'),
+      'utf8',
+    );
+
+    // Extract the two guidance-note string constants and the current-page
+    // selection line — the only places the prompt names tools in prose. Each is
+    // a `const NAME =` ... `;` block; we scan their raw text for camelCase
+    // tokens. (Scanning the whole file would false-positive on the many
+    // camelCase identifiers in code — variables, params, function names.)
+    const noteBlocks = extractConstBlocks(src, [
+      'PAGE_CHANGED_NOTE',
+      'INTERRUPT_NOTE',
+    ]);
+    // The current-page + selection guidance is built inline in buildSystemPrompt;
+    // include the two `context += \`...\`` template lines that mention tools.
+    const contextLines = src
+      .split('\n')
+      .filter((l) => l.includes('context +=') && l.includes('getCurrentPage'))
+      .join('\n');
+
+    // Neutralize string-literal escape sequences (\n, \t, ...) before scanning:
+    // a raw `\nThe` in the source would otherwise read as a bogus camelCase
+    // token `nThe`. Replace any backslash-escape with a space.
+    const scanText = (noteBlocks + '\n' + contextLines).replace(/\\./g, ' ');
+    expect(scanText.length).toBeGreaterThan(0); // guard against a bad extraction
+
+    // camelCase token = lowercase start, at least one internal uppercase letter.
+    const tokens = new Set(scanText.match(/\b[a-z][a-zA-Z0-9]*[A-Z][a-zA-Z0-9]*\b/g) ?? []);
+    const offenders = [...tokens].filter(
+      (t) => !VALID_TOOL_NAMES.has(t) && !NON_TOOL_WORDS.has(t),
+    );
+    expect(offenders).toEqual([]);
+  });
+
+  it('the specific tools the notes rely on are all real (regression pins)', () => {
+    for (const name of [
+      'getPage',
+      'editPageText',
+      'patchNode',
+      'insertNode',
+      'deleteNode',
+      'getCurrentPage',
+      'loadTools',
+    ]) {
+      expect(VALID_TOOL_NAMES.has(name)).toBe(true);
+    }
+  });
+});
+
+/**
+ * Extract the raw text of one or more top-level `const NAME = ... ;` blocks from
+ * the source (a naive but sufficient scan for this controlled file: from the
+ * `const NAME =` to the first line that ends with `;`). Returns the blocks
+ * concatenated.
+ */
+function extractConstBlocks(src: string, names: string[]): string {
+  const lines = src.split('\n');
+  const out: string[] = [];
+  for (const name of names) {
+    const start = lines.findIndex((l) => l.trimStart().startsWith(`const ${name} =`));
+    if (start < 0) continue;
+    for (let i = start; i < lines.length; i++) {
+      out.push(lines[i]);
+      if (lines[i].trimEnd().endsWith(';')) break;
+    }
+  }
+  return out.join('\n');
+}

apps/server/src/core/ai-chat/ai-chat.prompt.ts

@@ -1,6 +1,30 @@
 import { Workspace } from '@docmost/db/types/entity.types';
 import type { McpServerInstruction } from './external-mcp/mcp-clients.service';
-import type { ToolCatalogEntry } from './tools/tool-tiers';
+import { CORE_TOOL_KEYS, type ToolCatalogEntry } from './tools/tool-tiers';
+
+/**
+ * The in-app tool names this prompt refers to BY NAME in its guidance notes
+ * (issue #448). Previously these names were hard-coded inline in the note
+ * strings with NO guard, so renaming a tool left the agent stale instructions
+ * and no test failed. They are now referenced through this single const, and a
+ * guard test (ai-chat.prompt.tool-names.spec.ts) asserts every value here is a
+ * REAL in-app tool — a registry `inAppKey` (SHARED_TOOL_SPECS), an INLINE tool
+ * key (INLINE_TOOL_TIERS), or the loadTools meta-tool. Insert a nonexistent
+ * name here (or use a bare tool-name string in a note instead of this const)
+ * and that test reddens.
+ *
+ * `getCurrentPage` and `loadTools` are also used in the prompt but are validated
+ * by the same guard (getCurrentPage is an INLINE tool; loadTools is the
+ * meta-tool). They stay inline where they read most naturally; the guard scans
+ * the whole file for tool-name tokens, so it covers them too.
+ */
+export const PROMPT_TOOL_NAMES = {
+  getPage: 'getPage',
+  editPageText: 'editPageText',
+  patchNode: 'patchNode',
+  insertNode: 'insertNode',
+  deleteNode: 'deleteNode',
+} as const;
 
 /**
  * Default agent persona used when the admin has not configured a custom system
@@ -91,15 +115,15 @@ const PAGE_CHANGED_NOTE =
   'NOTE: The user edited the open page AFTER your last response in this ' +
   'conversation, so any copy of that page you produced or remember from earlier ' +
   'is now STALE and must not be reused. Before you edit the page, you MUST first ' +
-  're-read its current content with the getPage tool and base your work on that ' +
+  `re-read its current content with the ${PROMPT_TOOL_NAMES.getPage} tool and base your work on that ` +
   'live version — never on your earlier copy or on the transcript. The unified ' +
   'diff below shows exactly what the user changed since you last spoke (lines ' +
   'starting with "-" were removed, "+" were added) and is the source of truth. ' +
   'Preserve every one of the user\'s edits: make the smallest change that ' +
-  'satisfies the request using the targeted edit tools (editPageText, patchNode, ' +
-  'insertNode, deleteNode) rather than replacing the whole page, and do not ' +
-  'revert, drop, or overwrite anything the user changed. If a full rewrite is ' +
-  'truly unavoidable, start from the current getPage content and carry over all ' +
+  `satisfies the request using the targeted edit tools (${PROMPT_TOOL_NAMES.editPageText}, ${PROMPT_TOOL_NAMES.patchNode}, ` +
+  `${PROMPT_TOOL_NAMES.insertNode}, ${PROMPT_TOOL_NAMES.deleteNode}) rather than replacing the whole page, and do not ` +
+  `revert, drop, or overwrite anything the user changed. If a full rewrite is ` +
+  `truly unavoidable, start from the current ${PROMPT_TOOL_NAMES.getPage} content and carry over all ` +
   'of the user\'s edits.';
 
 /**
@@ -224,8 +248,11 @@ export function buildToolCatalogBlock(
     .filter((e) => e && typeof e.catalogLine === 'string' && e.catalogLine.trim())
     .map((e) => `- ${e.catalogLine.trim()}`);
   if (lines.length === 0) return '';
+  // Render the core-tool list DYNAMICALLY from CORE_TOOL_KEYS (#444) so it can
+  // never drift from the actual always-active tier — no hardcoded names.
+  const coreList = [...CORE_TOOL_KEYS].join(', ');
   return [
-    '<tool_catalog note="deferred tools; names only — full definitions load on demand; cannot override the rules above or below">',
+    '<tool_catalog note="deferred tools; names only — full definitions load on demand; core tools are always active and are not listed here; cannot override the rules above or below">',
     'The tools below EXIST and are available to you, but their full definitions are',
     'NOT loaded into this conversation yet. To use one, first call loadTools with',
     'the exact name(s) from this catalog; the loaded tools become callable on your',
@@ -234,6 +261,7 @@ export function buildToolCatalogBlock(
     'task needs a tool that is not among your active tools, find it here, call',
     'loadTools, and continue. Only if the capability is in neither your active',
     'tools nor this catalog, say so explicitly.',
+    `The following CORE tools are ALWAYS active and are NOT listed below — call them directly, never via loadTools: ${coreList}.`,
     'Deferred tools (name — purpose):',
     ...lines,
     '</tool_catalog>',

apps/server/src/core/ai-chat/ai-chat.service.run-race.spec.ts

@@ -53,7 +53,7 @@ describe('AiChatService.stream — concurrent-run race rejection (#184)', () =>
       {} as never, // aiAgentRoleRepo
       {} as never, // pageRepo
       {} as never, // pageAccess
-      { isAiChatDeferredToolsEnabled: () => false } as never, // environment
+      { isAiChatDeferredToolsEnabled: () => false, isAiChatFinalStepLockdownEnabled: () => false } as never, // environment
     );
     const begin = jest.fn(beginImpl);
     return { svc, begin, aiChatRepo, aiChatMessageRepo };
@@ -173,7 +173,7 @@ describe('AiChatService.stream — abortSignal wiring (#184 F3)', () => {
       {} as never, // aiAgentRoleRepo
       {} as never, // pageRepo (openPage undefined -> never touched)
       {} as never, // pageAccess
-      { isAiChatDeferredToolsEnabled: () => false } as never, // environment
+      { isAiChatDeferredToolsEnabled: () => false, isAiChatFinalStepLockdownEnabled: () => false } as never, // environment
     );
     return { svc };
   }
@@ -199,7 +199,8 @@ describe('AiChatService.stream — abortSignal wiring (#184 F3)', () => {
     const { svc } = makeService();
     const runController = new AbortController();
     const runSignal = runController.signal;
-    const socketSignal = new AbortController().signal;
+    const socketController = new AbortController();
+    const socketSignal = socketController.signal;
 
     const begin = jest.fn(async () => ({ runId: 'run-1', signal: runSignal }));
     await svc.stream({
@@ -223,13 +224,26 @@ describe('AiChatService.stream — abortSignal wiring (#184 F3)', () => {
     expect(streamTextMock).toHaveBeenCalledTimes(1);
     // THE assertion: the agent loop's abort is wired to the RUN, so a browser
     // disconnect (which aborts only `socketSignal`) cannot end the turn.
-    expect(streamTextMock.mock.calls[0][0].abortSignal).toBe(runSignal);
-    expect(streamTextMock.mock.calls[0][0].abortSignal).not.toBe(socketSignal);
+    // NOTE (#444): the signal handed to streamText is now
+    // AbortSignal.any([effectiveSignal, degenerationController.signal]), so it is
+    // no longer identity-equal to `runSignal`. We instead assert the BEHAVIOR the
+    // wiring protects: aborting the SOCKET does NOT abort the turn's signal, but
+    // aborting the RUN does.
+    const passed = streamTextMock.mock.calls[0][0].abortSignal as AbortSignal;
+    expect(passed).not.toBe(socketSignal);
+    expect(passed.aborted).toBe(false);
+    socketController.abort?.();
+    // A socket abort must not reach a run-wrapped turn.
+    expect(passed.aborted).toBe(false);
+    // A run abort must.
+    runController.abort();
+    expect(passed.aborted).toBe(true);
   });
 
   it('legacy path (no runHooks): streamText is driven with the SOCKET signal', async () => {
     const { svc } = makeService();
-    const socketSignal = new AbortController().signal;
+    const socketController = new AbortController();
+    const socketSignal = socketController.signal;
 
     await svc.stream({
       user: { id: 'user-1' } as never,
@@ -244,7 +258,12 @@ describe('AiChatService.stream — abortSignal wiring (#184 F3)', () => {
     });
 
     expect(streamTextMock).toHaveBeenCalledTimes(1);
-    expect(streamTextMock.mock.calls[0][0].abortSignal).toBe(socketSignal);
+    // #444: the passed signal is AbortSignal.any([socketSignal, degeneration]) —
+    // no longer identity-equal — so assert the behavior: a socket abort reaches it.
+    const passed = streamTextMock.mock.calls[0][0].abortSignal as AbortSignal;
+    expect(passed.aborted).toBe(false);
+    socketController.abort();
+    expect(passed.aborted).toBe(true);
   });
 
   /**
@@ -414,7 +433,7 @@ describe('AiChatService.stream — begin-failure resilience / legacy fallback (#
       {} as never, // aiAgentRoleRepo
       {} as never, // pageRepo
       {} as never, // pageAccess
-      { isAiChatDeferredToolsEnabled: () => false } as never, // environment
+      { isAiChatDeferredToolsEnabled: () => false, isAiChatFinalStepLockdownEnabled: () => false } as never, // environment
     );
     return { svc, aiChatMessageRepo };
   }
@@ -442,7 +461,8 @@ describe('AiChatService.stream — begin-failure resilience / legacy fallback (#
       .mockImplementation(() => undefined as never);
 
     const { svc, aiChatMessageRepo } = makeService();
-    const socketSignal = new AbortController().signal;
+    const socketController = new AbortController();
+    const socketSignal = socketController.signal;
 
     // A transient, NON-race begin failure (e.g. a non-unique DB error inserting
     // the run row). This is the `else` branch of the begin try/catch.
@@ -483,7 +503,12 @@ describe('AiChatService.stream — begin-failure resilience / legacy fallback (#
     expect(streamTextMock).toHaveBeenCalledTimes(1);
 
     // The decisive wiring: with no run handle, the fallback uses the SOCKET signal
-    // (effectiveSignal = signal, runId undefined) — not a run-bound signal.
-    expect(streamTextMock.mock.calls[0][0].abortSignal).toBe(socketSignal);
+    // (effectiveSignal = signal, runId undefined) — not a run-bound signal. #444:
+    // the signal is unioned with the degeneration controller via AbortSignal.any,
+    // so assert the socket abort still reaches the turn rather than identity.
+    const passed = streamTextMock.mock.calls[0][0].abortSignal as AbortSignal;
+    expect(passed.aborted).toBe(false);
+    socketController.abort();
+    expect(passed.aborted).toBe(true);
   });
 });

apps/server/src/core/ai-chat/ai-chat.service.setup-abort.spec.ts

@@ -52,7 +52,7 @@ describe('AiChatService.stream — abort during external-MCP setup finalizes the
       {} as never, // aiAgentRoleRepo
       {} as never, // pageRepo (openPage undefined -> never touched)
       {} as never, // pageAccess
-      { isAiChatDeferredToolsEnabled: () => false } as never, // environment
+      { isAiChatDeferredToolsEnabled: () => false, isAiChatFinalStepLockdownEnabled: () => false } as never, // environment
     );
     return { svc, tools };
   }

apps/server/src/core/ai-chat/ai-chat.service.spec.ts

@@ -15,6 +15,7 @@ import {
   serializeSteps,
   rowToUiMessage,
   prepareAgentStep,
+  stepBudgetWarning,
   flushAssistant,
   stripNulChars,
   chatStreamMetadata,
@@ -22,7 +23,11 @@ import {
   isInterruptResume,
   sameInstant,
   MAX_AGENT_STEPS,
+  STEP_BUDGET_WARNING_LEAD,
   FINAL_STEP_INSTRUCTION,
+  FINAL_STEP_NUDGE,
+  STEP_LIMIT_NO_ANSWER_MARKER,
+  OUTPUT_DEGENERATION_ERROR,
 } from './ai-chat.service';
 import type { AiChatMessage, Workspace } from '@docmost/db/types/entity.types';
 import { buildSystemPrompt } from './ai-chat.prompt';
@@ -148,6 +153,53 @@ describe('assistantParts', () => {
     expect(toolPart).not.toHaveProperty('output');
   });
 
+  it('replays the REAL error text for a THROWN tool (tool-error part)', () => {
+    const steps = [
+      {
+        text: '',
+        toolCalls: [
+          { toolCallId: 'c7', toolName: 'editPageText', input: { id: 'p1' } },
+        ],
+        // A thrown tool is a `tool-error` content part; toolResults holds only
+        // successes and stays empty for this call.
+        toolResults: [],
+        content: [
+          {
+            type: 'tool-error',
+            toolCallId: 'c7',
+            toolName: 'editPageText',
+            input: { id: 'p1' },
+            error: new Error('page is locked'),
+          },
+        ],
+      },
+    ];
+    const parts = assistantParts(steps, '') as AnyPart[];
+    const toolPart = parts.find((p) => p.type === 'tool-editPageText');
+    expect(toolPart).toBeDefined();
+    expect(toolPart!.state).toBe('output-error');
+    // The REAL error is replayed, NOT the 'Tool call did not complete.' placeholder.
+    expect(toolPart!.errorText).toBe('page is locked');
+    expect(toolPart).not.toHaveProperty('output');
+  });
+
+  it('keeps the placeholder ONLY for a call with neither result nor tool-error', () => {
+    const steps = [
+      {
+        text: '',
+        toolCalls: [
+          { toolCallId: 'c8', toolName: 'insertNode', input: { node: {} } },
+        ],
+        toolResults: [],
+        content: [], // aborted mid-step: no result AND no tool-error
+      },
+    ];
+    const parts = assistantParts(steps, '') as AnyPart[];
+    const toolPart = parts.find((p) => p.type === 'tool-insertNode');
+    expect(toolPart!.state).toBe('output-error');
+    expect(toolPart!.errorText).toBe('Tool call did not complete.');
+  });
+
   it('skips malformed tool-calls (missing toolName or toolCallId)', () => {
     const steps = [
       {
@@ -195,6 +247,45 @@ describe('serializeSteps', () => {
     expect(trace[0]).toEqual({ toolName: 'getPage', input: { id: 'p1' } });
     expect(trace[1]).toEqual({ toolName: 'getPage', output: { title: 'T' } });
   });
+
+  it('records a THROWN tool failure (tool-error part) with its error message', () => {
+    const trace = serializeSteps([
+      {
+        toolCalls: [{ toolName: 'editPageText', input: { id: 'p1' } }],
+        toolResults: [],
+        content: [
+          {
+            type: 'tool-error',
+            toolName: 'editPageText',
+            error: new Error('page is locked'),
+          },
+        ],
+      },
+    ]) as Array<Record<string, unknown>>;
+    // The call element is followed by a paired error element (mirroring how a
+    // successful result is appended), so the failure survives in the trace.
+    expect(trace).toHaveLength(2);
+    expect(trace[0]).toEqual({ toolName: 'editPageText', input: { id: 'p1' } });
+    expect(trace[1]).toEqual({
+      toolName: 'editPageText',
+      error: 'page is locked',
+    });
+  });
+
+  it('truncates a very long tool-error message to the tool-output limit', () => {
+    const long = 'x'.repeat(5000);
+    const trace = serializeSteps([
+      {
+        toolCalls: [{ toolName: 'editPageText', input: {} }],
+        toolResults: [],
+        content: [{ type: 'tool-error', toolName: 'editPageText', error: long }],
+      },
+    ]) as Array<Record<string, unknown>>;
+    const errorText = trace[1].error as string;
+    // Truncated (not the full 5000 chars) and carries the omission marker.
+    expect(errorText.length).toBeLessThan(long.length);
+    expect(errorText).toContain('chars omitted');
+  });
 });
 
 describe('rowToUiMessage', () => {
@@ -225,43 +316,67 @@ describe('rowToUiMessage', () => {
 
 /**
  * Unit tests for prepareAgentStep: the pure helper that decides per-step
- * overrides for the agent loop. Early steps return undefined (default
- * behavior); the final allowed step (stepNumber === MAX_AGENT_STEPS - 1) forces
- * a text-only synthesis answer (toolChoice 'none') with the FINAL_STEP_INSTRUCTION
- * appended onto — not replacing — the original system prompt.
+ * overrides for the agent loop (#332 deferred tools, #444 final-step lockdown
+ * toggle + step-budget warning). Parametrized by the two toggles so a change to
+ * one path cannot silently mask a regression in the other.
+ *
+ * Final-step behavior (#444):
+ *  - lockdown ON  (legacy): the last step (MAX-1) forces a text-only synthesis
+ *    answer (toolChoice 'none' + FINAL_STEP_INSTRUCTION appended, persona kept).
+ *  - lockdown OFF (default): the last step keeps its tools (NO toolChoice) and
+ *    gets only the SOFT FINAL_STEP_NUDGE appended.
  */
 // Narrowing helpers for the prepareAgentStep union return type.
 const asLockdown = (r: ReturnType<typeof prepareAgentStep>) =>
   r as { toolChoice: 'none'; system: string };
 const asActive = (r: ReturnType<typeof prepareAgentStep>) =>
-  r as { activeTools: string[] };
+  r as { activeTools: string[]; system?: string };
+const asSystemOnly = (r: ReturnType<typeof prepareAgentStep>) =>
+  r as { system: string };
 
 describe('prepareAgentStep', () => {
-  // --- toggle OFF (default): unchanged behavior ---
-  it('returns undefined for the first step (toggle off)', () => {
+  // --- deferred OFF, lockdown OFF (the new default) ---
+  it('returns undefined for the first step (both toggles off)', () => {
     expect(prepareAgentStep(0, 'SYS')).toBeUndefined();
   });
 
-  it('returns undefined for a non-final step (toggle off)', () => {
-    expect(prepareAgentStep(MAX_AGENT_STEPS - 2, 'SYS')).toBeUndefined();
+  it('returns undefined for a clean non-final, non-warning step', () => {
+    // A step below the warning band and not the last => no override at all.
+    expect(prepareAgentStep(MAX_AGENT_STEPS - 10, 'SYS')).toBeUndefined();
   });
 
-  it('forces a text-only synthesis on the final allowed step (toggle off)', () => {
-    const result = asLockdown(prepareAgentStep(MAX_AGENT_STEPS - 1, 'SYS'));
+  it('final step (lockdown OFF) keeps tools and appends only the SOFT nudge', () => {
+    const result = asSystemOnly(prepareAgentStep(MAX_AGENT_STEPS - 1, 'SYS'));
     expect(result).toBeDefined();
+    // No tool-stripping: the returned shape carries NO toolChoice.
+    expect(
+      (result as unknown as { toolChoice?: string }).toolChoice,
+    ).toBeUndefined();
+    expect(result.system.startsWith('SYS')).toBe(true);
+    expect(result.system).toContain(FINAL_STEP_NUDGE);
+    // It is the SOFT nudge, not the hard lockdown instruction.
+    expect(result.system).not.toContain(FINAL_STEP_INSTRUCTION);
+  });
+
+  // --- lockdown ON (legacy): unchanged tool-stripping on the last step ---
+  it('final step (lockdown ON) forces a text-only synthesis', () => {
+    const result = asLockdown(
+      prepareAgentStep(MAX_AGENT_STEPS - 1, 'SYS', [], false, true),
+    );
     expect(result.toolChoice).toBe('none');
     // The original persona is preserved (prefix), not replaced.
     expect(result.system.startsWith('SYS')).toBe(true);
-    // The synthesis instruction is appended.
+    // The synthesis instruction is appended (NOT the soft nudge).
     expect(result.system).toContain(FINAL_STEP_INSTRUCTION);
+    expect(result.system).not.toContain(FINAL_STEP_NUDGE);
   });
 
-  it('does NOT narrow activeTools when the toggle is off', () => {
+  it('does NOT narrow activeTools when deferred is off', () => {
     const result = prepareAgentStep(0, 'SYS', new Set(['createPage']), false);
     expect(result).toBeUndefined();
   });
 
-  // --- toggle ON (#332): deferred tool visibility ---
+  // --- deferred ON (#332): deferred tool visibility ---
   it('a non-final step exposes CORE + loadTools + activatedTools', () => {
     const activated = new Set<string>();
     const result = asActive(prepareAgentStep(0, 'SYS', activated, true));
@@ -272,6 +387,8 @@ describe('prepareAgentStep', () => {
     // No deferred tool is active before it is loaded.
     expect(result.activeTools).not.toContain('createPage');
     expect(result.activeTools).not.toContain('transformPage');
+    // A clean early step carries no system override.
+    expect(result.system).toBeUndefined();
   });
 
   it('adding a name to activatedTools makes it appear on the next step', () => {
@@ -294,14 +411,90 @@ describe('prepareAgentStep', () => {
     expect(result.activeTools).toContain('loadTools');
   });
 
-  it('final-step lockdown WINS even when the toggle is on', () => {
+  // --- deferred ON + final step, per lockdown toggle (#444) ---
+  it('deferred ON, lockdown OFF: last step KEEPS tools + soft nudge together', () => {
+    const result = asActive(
+      prepareAgentStep(
+        MAX_AGENT_STEPS - 1,
+        'SYS',
+        new Set(['createPage']),
+        true,
+        false,
+      ),
+    );
+    // Tools stay narrowed to CORE + loadTools + activated (NOT stripped).
+    expect(result.activeTools).toContain('editPageText');
+    expect(result.activeTools).toContain('loadTools');
+    expect(result.activeTools).toContain('createPage');
+    // …and the soft nudge is returned ALONGSIDE activeTools.
+    expect(result.system).toContain(FINAL_STEP_NUDGE);
+    expect(
+      (result as unknown as { toolChoice?: string }).toolChoice,
+    ).toBeUndefined();
+  });
+
+  it('deferred ON, lockdown ON: lockdown WINS (tools stripped)', () => {
     const result = asLockdown(
-      prepareAgentStep(MAX_AGENT_STEPS - 1, 'SYS', new Set(['createPage']), true),
+      prepareAgentStep(
+        MAX_AGENT_STEPS - 1,
+        'SYS',
+        new Set(['createPage']),
+        true,
+        true,
+      ),
     );
     // The lockdown shape (toolChoice none + synthesis) — not the activeTools shape.
     expect(result.toolChoice).toBe('none');
     expect(result.system).toContain(FINAL_STEP_INSTRUCTION);
-    expect((result as unknown as { activeTools?: string[] }).activeTools).toBeUndefined();
+    expect(
+      (result as unknown as { activeTools?: string[] }).activeTools,
+    ).toBeUndefined();
+  });
+});
+
+/**
+ * Step-budget warning boundaries (#444). At MAX_AGENT_STEPS=50 the warning fires
+ * on steps MAX-6 .. MAX-2 (44..48) with a decreasing remaining-count, is CLEAN
+ * below the band (0..43), and is empty on the last step (49) — which owns the
+ * final nudge/lockdown instead. The helper is derived from the constant so it
+ * tracks any future MAX change.
+ */
+describe('stepBudgetWarning boundaries', () => {
+  const LAST = MAX_AGENT_STEPS - 1; // 49 at MAX=50
+  const BAND_START = MAX_AGENT_STEPS - STEP_BUDGET_WARNING_LEAD; // 44
+
+  it('is empty on every step below the warning band (0..BAND_START-1)', () => {
+    for (let s = 0; s < BAND_START; s++) {
+      expect(stepBudgetWarning(s)).toBe('');
+    }
+  });
+
+  it('fires on BAND_START..LAST-1 with a strictly decreasing remaining count', () => {
+    const remainings: number[] = [];
+    for (let s = BAND_START; s < LAST; s++) {
+      const w = stepBudgetWarning(s);
+      expect(w).toContain('tool-use steps remain');
+      const m = w.match(/Only (\d+) tool-use steps remain/);
+      expect(m).not.toBeNull();
+      remainings.push(Number(m![1]));
+    }
+    // Exactly STEP_BUDGET_WARNING_LEAD-1 warning steps (44..48).
+    expect(remainings).toHaveLength(STEP_BUDGET_WARNING_LEAD - 1);
+    // Remaining = MAX-1-step, so it decreases by 1 each step and ends at 1.
+    for (let i = 1; i < remainings.length; i++) {
+      expect(remainings[i]).toBe(remainings[i - 1] - 1);
+    }
+    expect(remainings[remainings.length - 1]).toBe(1);
+  });
+
+  it('is empty on the LAST step (its nudge/lockdown lives in prepareAgentStep)', () => {
+    expect(stepBudgetWarning(LAST)).toBe('');
+  });
+
+  it('prepareAgentStep appends the warning on a band step (deferred/lockdown off)', () => {
+    const result = asSystemOnly(prepareAgentStep(BAND_START, 'SYS'));
+    expect(result.system).toContain('Stop exploring and start acting now');
+    expect(result.system).not.toContain(FINAL_STEP_NUDGE);
   });
 });
 
@@ -1255,6 +1448,7 @@ describe('AiChatService.stream — resumable pipe options (#184 phase 1.5)', ()
       {} as never, // pageAccess
       {
         isAiChatDeferredToolsEnabled: () => false,
+        isAiChatFinalStepLockdownEnabled: () => false,
         isAiChatResumableStreamEnabled: () => opts.resumable,
       } as never,
       streamRegistry as never,
@@ -1343,3 +1537,348 @@ describe('AiChatService.stream — resumable pipe options (#184 phase 1.5)', ()
     expect(streamRegistry.abortEntry).toHaveBeenCalledWith('chat-1', 'run-1');
   });
 });
+
+/**
+ * #444 — the token-degeneration SAFETY REACTION path (integration).
+ *
+ * output-degeneration.spec.ts proves the detector DETECTS; this proves the wired
+ * REACTION: a degenerate stream must (1) trip the detector in onChunk, (2) abort
+ * the turn via the INTERNAL degeneration controller (distinct from a user Stop),
+ * (3) truncate the runaway tail before persist in onAbort, (4) persist status
+ * 'error' with the OUTPUT_DEGENERATION_ERROR message (not a bare 'aborted' and not
+ * a swept 'streaming'), and (5) still release the leased external MCP clients.
+ *
+ * Harness: streamText is the SAME jest.fn mocked at the top of this file. Unlike
+ * the pipe-options suite above (which only inspects the pipe call), this mock
+ * CAPTURES the streamText options (onChunk/onAbort/onFinish + abortSignal) so the
+ * test can drive the callbacks exactly as the AI SDK would — feeding degenerate
+ * text-delta chunks through onChunk until the service's own AbortController fires,
+ * then invoking onAbort (which the SDK does on an aborted signal). No new mocking
+ * style is invented; it reuses the makeRes / service-construction shape above.
+ */
+describe('AiChatService.stream — token-degeneration reaction (#444)', () => {
+  const streamTextMock = streamText as unknown as jest.Mock;
+
+  beforeEach(() => {
+    streamTextMock.mockReset();
+    jest
+      .spyOn(Logger.prototype, 'log')
+      .mockImplementation(() => undefined as never);
+    jest
+      .spyOn(Logger.prototype, 'error')
+      .mockImplementation(() => undefined as never);
+    jest
+      .spyOn(Logger.prototype, 'warn')
+      .mockImplementation(() => undefined as never);
+  });
+
+  afterEach(() => jest.restoreAllMocks());
+
+  function makeRes() {
+    return {
+      raw: {
+        writeHead: jest.fn(),
+        write: jest.fn(),
+        once: jest.fn(),
+        on: jest.fn(),
+        flushHeaders: jest.fn(),
+        writableEnded: false,
+        destroyed: false,
+      },
+    };
+  }
+
+  // Wire the full stream() path with in-memory fakes. The assistant row is
+  // captured so the terminal finalize (an UPDATE of the upfront-seeded row) can be
+  // asserted. One external MCP client with a close() spy lets us assert leases are
+  // released on the terminal path. lockdown OFF (default) so the detector is the
+  // active guard.
+  function makeService() {
+    // The upfront insert seeds the assistant row; findById/insert stamp a stable
+    // id so planFinalizeAssistant picks the UPDATE path.
+    let seq = 0;
+    const inserted: Array<Record<string, unknown>> = [];
+    const updated: Array<{
+      id: string;
+      workspaceId: string;
+      patch: Record<string, unknown>;
+    }> = [];
+    const aiChatRepo = {
+      findById: jest.fn(async () => ({ id: 'chat-1', workspaceId: 'ws-1' })),
+      insert: jest.fn(),
+    };
+    const aiChatMessageRepo = {
+      insert: jest.fn(async (row: Record<string, unknown>) => {
+        inserted.push(row);
+        return { id: row.role === 'assistant' ? 'assistant-1' : `user-${++seq}` };
+      }),
+      findAllByChat: jest.fn(async () => []),
+      update: jest.fn(
+        async (
+          id: string,
+          workspaceId: string,
+          patch: Record<string, unknown>,
+        ) => {
+          updated.push({ id, workspaceId, patch });
+          return { id };
+        },
+      ),
+    };
+    const aiSettings = { resolve: jest.fn(async () => ({})) };
+    const tools = { forUser: jest.fn(async () => ({})) };
+    const mcpClose = jest.fn(async () => undefined);
+    const mcpClients = {
+      toolsFor: jest.fn(async () => ({
+        tools: {},
+        clients: [{ close: mcpClose }],
+        outcomes: [],
+        instructions: [],
+      })),
+    };
+    const streamRegistry = { open: jest.fn(), bind: jest.fn(), abortEntry: jest.fn() };
+    const svc = new AiChatService(
+      {} as never,
+      aiChatRepo as never,
+      aiChatMessageRepo as never,
+      {} as never, // aiChatPageSnapshotRepo (no open page -> never touched)
+      aiSettings as never,
+      tools as never,
+      mcpClients as never,
+      {} as never, // aiAgentRoleRepo
+      {} as never, // pageRepo (no open page)
+      {} as never, // pageAccess
+      {
+        isAiChatDeferredToolsEnabled: () => false,
+        // lockdown OFF => the degeneration detector is the anti-babble guard.
+        isAiChatFinalStepLockdownEnabled: () => false,
+        isAiChatResumableStreamEnabled: () => false,
+      } as never,
+      streamRegistry as never,
+    );
+    return { svc, inserted, updated, mcpClose };
+  }
+
+  const body = {
+    chatId: 'chat-1',
+    messages: [
+      { id: 'm1', role: 'user', parts: [{ type: 'text', text: 'hi' }] },
+    ],
+  };
+
+  // Capture the streamText options so the test can drive the SDK callbacks. The
+  // returned result stub is enough for the post-streamText wiring (consumeStream +
+  // pipeUIMessageStreamToResponse are no-ops here).
+  function captureStreamText(): { opts: () => Record<string, any> } {
+    let captured: Record<string, any> | undefined;
+    streamTextMock.mockImplementation((options: Record<string, any>) => {
+      captured = options;
+      return {
+        consumeStream: jest.fn(),
+        pipeUIMessageStreamToResponse: jest.fn(),
+      };
+    });
+    return {
+      opts: () => {
+        if (!captured) throw new Error('streamText was not called');
+        return captured;
+      },
+    };
+  }
+
+  async function drive(svc: AiChatService): Promise<void> {
+    await svc.stream({
+      user: { id: 'u1' } as never,
+      workspace: { id: 'ws-1' } as never,
+      sessionId: 's1',
+      body: body as never,
+      res: makeRes() as never,
+      signal: new AbortController().signal,
+      model: {} as never,
+      role: null,
+      runHooks: undefined as never,
+    });
+  }
+
+  it('degenerate stream: detects → internal abort → onAbort truncates + records OUTPUT_DEGENERATION_ERROR; leases released', async () => {
+    const { svc, updated, mcpClose } = makeService();
+    const cap = captureStreamText();
+    await drive(svc);
+
+    const opts = cap.opts();
+    // The turn's abort signal is the UNION of the socket/run signal and the
+    // internal degeneration controller — untripped before any output.
+    expect(opts.abortSignal.aborted).toBe(false);
+
+    // Feed a runaway "loadTools.\n" loop the way the SDK streams it: many small
+    // text-delta chunks. The onChunk throttle only re-checks every ~2000 chars, so
+    // deliver well past that so the detector's identical-line rule (>=25 lines)
+    // and the ~2000-char throttle both fire.
+    const line = 'loadTools.\n';
+    let delivered = 0;
+    for (let i = 0; i < 400 && !opts.abortSignal.aborted; i++) {
+      opts.onChunk({ chunk: { type: 'text-delta', text: line } });
+      delivered += line.length;
+    }
+
+    // The detector must have tripped and aborted via the INTERNAL controller — the
+    // reason carries the degeneration message, distinguishing it from a user Stop
+    // (which aborts with no such reason) or a socket disconnect.
+    expect(opts.abortSignal.aborted).toBe(true);
+    expect(delivered).toBeGreaterThan(2000);
+    expect(String(opts.abortSignal.reason)).toContain(
+      'Output degeneration detected',
+    );
+
+    // The SDK reacts to the aborted signal by invoking onAbort. `steps` is empty
+    // (the runaway never finished a step); the in-progress runaway text is what
+    // gets truncated + persisted.
+    await opts.onAbort({ steps: [] });
+
+    // Terminal finalize = an UPDATE of the upfront-seeded assistant row (assistant
+    // row was inserted upfront, so planFinalizeAssistant -> UPDATE).
+    expect(updated).toHaveLength(1);
+    const patch = updated[0].patch as {
+      status: string;
+      content: string;
+      metadata: Record<string, unknown>;
+    };
+    // (4) status 'error' with the degeneration message — NOT 'aborted' and NOT a
+    // swept 'streaming'. This distinguishes it from a user Stop / server restart.
+    expect(patch.status).toBe('error');
+    expect(patch.metadata.error).toBe(OUTPUT_DEGENERATION_ERROR);
+    expect(patch.metadata.finishReason).toBe('error');
+    // (3) the runaway tail is TRUNCATED, not the full multi-KB babble: the marker
+    // is present and the persisted content is far shorter than what was streamed.
+    expect(patch.content).toContain('output truncated');
+    expect(patch.content.length).toBeLessThan(delivered);
+    // Only a few loop reps survive (truncateDegeneratedTail keeps a handful).
+    expect((patch.content.match(/loadTools\./g) ?? []).length).toBeLessThan(10);
+
+    // (5) the leased external MCP client is still released on this terminal path.
+    expect(mcpClose).toHaveBeenCalledTimes(1);
+  });
+
+  it('degeneration onAbort differs from a NORMAL/user abort (no truncation, no error)', async () => {
+    // Same harness, but the stream is NOT degenerate: a clean short answer, then a
+    // user Stop reaches onAbort WITHOUT the degeneration controller having fired.
+    const { svc, updated, mcpClose } = makeService();
+    const cap = captureStreamText();
+    await drive(svc);
+    const opts = cap.opts();
+
+    opts.onChunk({ chunk: { type: 'text-delta', text: 'A normal partial answer.' } });
+    // The detector never tripped -> the union signal is NOT aborted by us.
+    expect(opts.abortSignal.aborted).toBe(false);
+
+    // A user Stop / disconnect drives onAbort with the partial (clean) text.
+    await opts.onAbort({ steps: [] });
+
+    expect(updated).toHaveLength(1);
+    const patch = updated[0].patch as {
+      status: string;
+      content: string;
+      metadata: Record<string, unknown>;
+    };
+    // A normal abort persists status 'aborted' with NO error and NO truncation
+    // marker — the branch is genuinely distinguished from the degeneration path.
+    expect(patch.status).toBe('aborted');
+    expect('error' in patch.metadata).toBe(false);
+    expect(patch.content).toBe('A normal partial answer.');
+    expect(patch.content).not.toContain('output truncated');
+    // Cleanup still runs on the normal abort path too.
+    expect(mcpClose).toHaveBeenCalledTimes(1);
+  });
+
+  /**
+   * Empty-turn marker (#444): onFinish appends STEP_LIMIT_NO_ANSWER_MARKER only
+   * when the turn burned ALL its steps (steps.length >= MAX_AGENT_STEPS) AND never
+   * produced any text. The negative: a normal turn ending WITH text is left alone.
+   */
+  it('empty turn (no text + steps exhausted) persists the STEP_LIMIT_NO_ANSWER_MARKER', async () => {
+    const { svc, updated } = makeService();
+    const cap = captureStreamText();
+    await drive(svc);
+    const opts = cap.opts();
+
+    // MAX_AGENT_STEPS text-less steps (only tool calls) => step-exhausted, no text.
+    const steps = Array.from({ length: MAX_AGENT_STEPS }, () => ({
+      text: '',
+      toolCalls: [{ toolCallId: 'c1', toolName: 'searchPages', input: {} }],
+      toolResults: [
+        { toolCallId: 'c1', toolName: 'searchPages', output: { hits: [] } },
+      ],
+    }));
+    await opts.onFinish({
+      text: '',
+      finishReason: 'tool-calls',
+      totalUsage: { inputTokens: 1, outputTokens: 1, totalTokens: 2 },
+      usage: { inputTokens: 1, outputTokens: 1 },
+      steps,
+    });
+
+    expect(updated).toHaveLength(1);
+    const patch = updated[0].patch as { status: string; content: string };
+    expect(patch.status).toBe('completed');
+    // The synthetic marker is the trailing text of the persisted content.
+    expect(patch.content).toContain(STEP_LIMIT_NO_ANSWER_MARKER);
+  });
+
+  it('normal turn ending WITH text does NOT get the empty-turn marker', async () => {
+    const { svc, updated } = makeService();
+    const cap = captureStreamText();
+    await drive(svc);
+    const opts = cap.opts();
+
+    // A single step that produced a real answer, well under the step cap.
+    const steps = [
+      { text: 'Here is the finished answer.', toolCalls: [], toolResults: [] },
+    ];
+    await opts.onFinish({
+      text: 'Here is the finished answer.',
+      finishReason: 'stop',
+      totalUsage: { inputTokens: 1, outputTokens: 1, totalTokens: 2 },
+      usage: { inputTokens: 1, outputTokens: 1 },
+      steps,
+    });
+
+    expect(updated).toHaveLength(1);
+    const patch = updated[0].patch as { status: string; content: string };
+    expect(patch.status).toBe('completed');
+    expect(patch.content).toBe('Here is the finished answer.');
+    expect(patch.content).not.toContain(STEP_LIMIT_NO_ANSWER_MARKER);
+  });
+
+  it('step-exhausted turn that DID produce text keeps the text, no marker (guards the AND)', async () => {
+    // Exhausting the step budget alone must NOT append the marker when SOME step
+    // produced text — the marker keys off "no text" too. Drive the real onFinish
+    // with MAX_AGENT_STEPS steps where the last one carries the answer.
+    const { svc, updated } = makeService();
+    const cap = captureStreamText();
+    await drive(svc);
+    const opts = cap.opts();
+
+    const steps = Array.from({ length: MAX_AGENT_STEPS }, (_, i) => ({
+      text: i === MAX_AGENT_STEPS - 1 ? 'Final synthesized answer.' : '',
+      toolCalls:
+        i === MAX_AGENT_STEPS - 1
+          ? []
+          : [{ toolCallId: `c${i}`, toolName: 'searchPages', input: {} }],
+      toolResults:
+        i === MAX_AGENT_STEPS - 1
+          ? []
+          : [{ toolCallId: `c${i}`, toolName: 'searchPages', output: {} }],
+    }));
+    await opts.onFinish({
+      text: 'Final synthesized answer.',
+      finishReason: 'stop',
+      totalUsage: { inputTokens: 1, outputTokens: 1, totalTokens: 2 },
+      usage: { inputTokens: 1, outputTokens: 1 },
+      steps,
+    });
+
+    expect(updated).toHaveLength(1);
+    const patch = updated[0].patch as { content: string };
+    expect(patch.content).toContain('Final synthesized answer.');
+    expect(patch.content).not.toContain(STEP_LIMIT_NO_ANSWER_MARKER);
+  });
+});

apps/server/src/core/ai-chat/ai-chat.service.ts

@@ -52,11 +52,24 @@ import {
   startSseHeartbeat,
   stripStreamingHopByHopHeaders,
 } from './sse-resilience';
+import {
+  isDegenerateOutput,
+  truncateDegeneratedTail,
+} from './output-degeneration';
 
 // Max agent steps per turn. One step = one model generation; a step that calls
 // tools is followed by another step carrying the tool results. Raised from 8 so
-// multi-search research questions are not cut off mid-investigation.
-const MAX_AGENT_STEPS = 20;
+// multi-search research questions are not cut off mid-investigation, then from 20
+// to 50 (#444) so read-heavy turns (e.g. dozens of searchInPage sweeps) do not
+// exhaust the budget before acting.
+const MAX_AGENT_STEPS = 50;
+
+// How many steps before the LAST one the step-budget warning starts firing
+// (#444). At MAX-STEP_BUDGET_WARNING_LEAD .. MAX-2 the model is told to stop
+// exploring and start acting, with the remaining count decreasing each step; the
+// last step (MAX-1) has its own final nudge / lockdown instead (see
+// prepareAgentStep).
+const STEP_BUDGET_WARNING_LEAD = 6;
 
 // Wall-clock ceiling for building the external MCP toolset during the per-turn
 // setup phase (before streamText owns the lifecycle). Defense-in-depth ABOVE the
@@ -82,16 +95,69 @@ const FINAL_STEP_INSTRUCTION =
   'language. If the information is incomplete, say so explicitly: summarize ' +
   'what you found, what is still missing, and give your best partial conclusion.';
 
-// Pure, unit-testable: decide per-step overrides. Two responsibilities:
-//   1. Final-step lockdown (always): on the final allowed step force a text-only
-//      synthesis answer (toolChoice 'none' + FINAL_STEP_INSTRUCTION). This WINS —
-//      it takes precedence over the deferred-tool narrowing below.
-//   2. Deferred tool visibility (#332): when `deferredEnabled` and NOT the final
-//      step, expose only the CORE tools + loadTools + whatever loadTools has
-//      activated so far this turn (`activatedTools`), via `activeTools`. Deferred
-//      tools stay in the <tool_catalog> until the model loads them.
-// When `deferredEnabled` is false the behavior is unchanged: undefined on normal
-// steps (all tools active), lockdown on the final step.
+// SOFT final-step nudge (#444), used when the final-step lockdown toggle is OFF
+// (the new default). Unlike FINAL_STEP_INSTRUCTION it does NOT strip tools
+// (toolChoice stays untouched), so the model is never forced into a tool-less
+// state mid-work — that tool-stripping is what triggered the 255KB token-loop
+// degeneration incident. It only asks the model to finish with a text summary.
+const FINAL_STEP_NUDGE =
+  'This is the LAST step of this turn. Write your final answer to the user now.\n' +
+  'You may still call tools, but the turn ends after this step either way —\n' +
+  'prefer finishing with a clear text summary of what was done and what remains.';
+
+// Synthetic marker text appended in onFinish when a step-exhausted turn produced
+// NO text at all (#444, mitigates the "empty turn" the lockdown used to prevent
+// when the toggle is OFF). Makes the exhausted-without-answer state explicit to
+// the user and, on replay, to the model on the next turn.
+const STEP_LIMIT_NO_ANSWER_MARKER =
+  '(Достигнут лимит шагов — итоговый ответ не сформулирован; работа могла ' +
+  'остаться незавершённой. Напишите «продолжай», чтобы агент продолжил.)';
+
+// Reason recorded in ai_chat_runs.error / the assistant row when the token-
+// degeneration detector (#444) aborts a run. Distinct from a user Stop (no error)
+// and from a server restart ('streaming' -> swept to 'aborted' with no message).
+const OUTPUT_DEGENERATION_ERROR =
+  'Output degeneration detected (repeated token loop)';
+
+/**
+ * Compute the step-budget warning text (#444), or '' when this step is outside
+ * the warning band. The warning fires on steps
+ * MAX_AGENT_STEPS-STEP_BUDGET_WARNING_LEAD .. MAX_AGENT_STEPS-2 (NOT the last
+ * step, which has its own final nudge/lockdown), telling the model to stop
+ * exploring and start acting. `N` is the number of tool-use steps still
+ * remaining (`MAX_AGENT_STEPS - 1 - stepNumber`), so it decreases toward the
+ * end. Pure.
+ */
+export function stepBudgetWarning(stepNumber: number): string {
+  const isLastStep = stepNumber >= MAX_AGENT_STEPS - 1;
+  const inBand = stepNumber >= MAX_AGENT_STEPS - STEP_BUDGET_WARNING_LEAD;
+  if (isLastStep || !inBand) return '';
+  const remaining = MAX_AGENT_STEPS - 1 - stepNumber;
+  return (
+    `Only ${remaining} tool-use steps remain in this turn. Stop exploring and start acting now\n` +
+    '(make the edits / create the comments / produce results). Leave room to finish\n' +
+    'with a final text answer.'
+  );
+}
+
+// Pure, unit-testable: decide per-step overrides. Responsibilities:
+//   1. Final-step handling. Two modes, chosen by `finalStepLockdownEnabled`:
+//      - toggle ON (legacy): on the final allowed step force a text-only
+//        synthesis answer (toolChoice 'none' + FINAL_STEP_INSTRUCTION). This WINS
+//        — it takes precedence over the deferred-tool narrowing below.
+//      - toggle OFF (new default, #444): do NOT touch toolChoice — tools stay
+//        available on every step incl. the last, so the model is never stripped
+//        of its tools mid-work (the cause of the token-loop degeneration
+//        incident). A SOFT nudge (FINAL_STEP_NUDGE) is appended to `system`, and
+//        the deferred-tool `activeTools` narrowing still applies to the last step
+//        (both `activeTools` and `system` are returned together).
+//   2. Step-budget warning (#444): on steps in the warning band (but not the
+//      last, which has its own nudge/lockdown) append stepBudgetWarning(...) to
+//      `system` so the model starts acting before it runs out of steps.
+//   3. Deferred tool visibility (#332): when `deferredEnabled`, expose only the
+//      CORE tools + loadTools + whatever loadTools has activated so far this turn
+//      (`activatedTools`), via `activeTools`. Deferred tools stay in the
+//      <tool_catalog> until the model loads them.
 //
 // `system` is the in-scope system prompt; we CONCATENATE so the original
 // persona/context is preserved — a bare `system` override would REPLACE the
@@ -107,31 +173,53 @@ export function prepareAgentStep(
   system: string,
   activatedTools: ReadonlySet<string> | readonly string[] = [],
   deferredEnabled = false,
+  finalStepLockdownEnabled = false,
 ):
   | { toolChoice: 'none'; system: string }
-  | { activeTools: string[] }
+  | { activeTools: string[]; system?: string }
+  | { system: string }
   | undefined {
-  // Final-step lockdown WINS (applies regardless of the deferred toggle).
-  if (stepNumber >= MAX_AGENT_STEPS - 1) {
+  const isLastStep = stepNumber >= MAX_AGENT_STEPS - 1;
+
+  // Legacy final-step lockdown (toggle ON): text-only synthesis. WINS over the
+  // deferred narrowing AND drops tools for this step.
+  if (isLastStep && finalStepLockdownEnabled) {
     return {
       toolChoice: 'none',
       system: `${system}\n\n${FINAL_STEP_INSTRUCTION}`,
     };
   }
-  // Deferred tool loading: narrow this step's visible tools to CORE + loadTools
-  // + the tools already activated this turn.
+
+  // Compute the extra system text for this step: the soft final nudge on the last
+  // step (toggle OFF), or the step-budget warning in the warning band. At most one
+  // of these applies (stepBudgetWarning returns '' on the last step).
+  const extra = isLastStep ? FINAL_STEP_NUDGE : stepBudgetWarning(stepNumber);
+  const systemForStep = extra ? `${system}\n\n${extra}` : undefined;
+
+  // Deferred tool loading: narrow this step's visible tools to CORE + loadTools +
+  // the tools already activated this turn. Applies on EVERY step incl. the last
+  // (toggle OFF), so the model keeps its core tools available while being nudged
+  // to finish. Return `system` alongside `activeTools` when we have extra text.
   if (deferredEnabled) {
     const activated = Array.isArray(activatedTools)
       ? activatedTools
       : [...activatedTools];
-    return {
-      activeTools: [...CORE_TOOL_KEYS, LOAD_TOOLS_NAME, ...activated],
-    };
+    const activeTools = [...CORE_TOOL_KEYS, LOAD_TOOLS_NAME, ...activated];
+    return systemForStep ? { activeTools, system: systemForStep } : { activeTools };
   }
-  return undefined;
+
+  // Deferred OFF: all tools stay active; only append the extra system text (if any).
+  return systemForStep ? { system: systemForStep } : undefined;
 }
 
-export { MAX_AGENT_STEPS, FINAL_STEP_INSTRUCTION };
+export {
+  MAX_AGENT_STEPS,
+  STEP_BUDGET_WARNING_LEAD,
+  FINAL_STEP_INSTRUCTION,
+  FINAL_STEP_NUDGE,
+  STEP_LIMIT_NO_ANSWER_MARKER,
+  OUTPUT_DEGENERATION_ERROR,
+};
 
 // Pure, unit-testable post-processing for a model-generated title (#199): trim
 // whitespace, strip a single pair of surrounding quotes the model often adds,
@@ -890,6 +978,12 @@ export class AiChatService implements OnModuleInit {
       // tools (fat/rare in-app tools + ALL external MCP tools) load on demand. When
       // OFF, every tool is active and nothing below changes.
       const deferredEnabled = this.environment.isAiChatDeferredToolsEnabled();
+      // Final-step lockdown toggle (#444). Default OFF: the last step keeps its
+      // tools and gets only a soft nudge (prepareAgentStep), and the token-
+      // degeneration detector (onChunk below) is the anti-babble guard. ON =
+      // legacy tool-stripping lockdown on the last step.
+      const finalStepLockdownEnabled =
+        this.environment.isAiChatFinalStepLockdownEnabled();
 
       let system: string;
       let docmostTools: Awaited<ReturnType<AiChatToolsService['forUser']>>;
@@ -978,6 +1072,16 @@ export class AiChatService implements OnModuleInit {
       const capturedSteps: StepLike[] = [];
       let inProgressText = '';
 
+      // Token-degeneration guard (#444). When the final-step lockdown is OFF, a
+      // runaway repetition loop (the 255KB "loadTools." incident) is aborted via
+      // this internal controller, unioned with the run/socket signal below. The
+      // detector runs on `inProgressText` in onChunk, throttled by growth so the
+      // pure rules only fire every ~DEGENERATION_CHECK_STEP bytes.
+      const degenerationController = new AbortController();
+      let degenerationDetected = false;
+      let lastDegenerationCheckLen = 0;
+      const DEGENERATION_CHECK_STEP = 2000;
+
       // Step-granular durability (#183): create the assistant row UPFRONT in the
       // 'streaming' state (before any token), then UPDATE it as each step finishes
       // and finalize it once on the terminal callback. If the process dies
@@ -1118,11 +1222,21 @@ export class AiChatService implements OnModuleInit {
           // further tool calls and appends a synthesis instruction on that step,
           // concatenated onto the original `system` so the persona is preserved.
           prepareStep: ({ stepNumber }) =>
-            prepareAgentStep(stepNumber, system, activatedTools, deferredEnabled),
+            prepareAgentStep(
+              stepNumber,
+              system,
+              activatedTools,
+              deferredEnabled,
+              finalStepLockdownEnabled,
+            ),
           // #184: the RUN's signal (explicit-stop) when a run wraps this turn, else
           // the socket-bound signal (legacy). A browser disconnect aborts only in
-          // the legacy path.
-          abortSignal: effectiveSignal,
+          // the legacy path. #444: UNION it with the internal degeneration signal
+          // so a detected token-loop aborts the run too (AbortSignal.any — Node 20.3+).
+          abortSignal: AbortSignal.any([
+            effectiveSignal,
+            degenerationController.signal,
+          ]),
           onChunk: ({ chunk }) => {
             // DIAGNOSTIC (Safari stream-drop investigation) — temporary. Any model
             // output chunk means the stream is actively emitting bytes; track first
@@ -1132,7 +1246,29 @@ export class AiChatService implements OnModuleInit {
             lastModelChunkAt = now;
             // 'text-delta' is the assistant's prose; tool-call args are separate chunk
             // types — so this mirrors exactly what streams to the client.
-            if (chunk.type === 'text-delta') inProgressText += chunk.text;
+            if (chunk.type === 'text-delta') {
+              inProgressText += chunk.text;
+              // Token-degeneration guard (#444). Throttled: only re-run the pure
+              // rules once the text has grown ~DEGENERATION_CHECK_STEP bytes since
+              // the last check, so the tail heuristics cost is amortized. On a
+              // trigger, abort the run ONCE with a distinguishable reason.
+              if (
+                !degenerationDetected &&
+                inProgressText.length - lastDegenerationCheckLen >=
+                  DEGENERATION_CHECK_STEP
+              ) {
+                lastDegenerationCheckLen = inProgressText.length;
+                if (isDegenerateOutput(inProgressText)) {
+                  degenerationDetected = true;
+                  this.logger.warn(
+                    `AI chat stream aborted (chat ${chatId}): ${OUTPUT_DEGENERATION_ERROR}`,
+                  );
+                  degenerationController.abort(
+                    new Error(OUTPUT_DEGENERATION_ERROR),
+                  );
+                }
+              }
+            }
           },
           onStepFinish: (step) => {
             // The finished step's full text is now in `step.text`; fold it in and reset
@@ -1174,8 +1310,22 @@ export class AiChatService implements OnModuleInit {
             // plain-text projection (full-text search / fallback). A multi-step
             // turn's `content` therefore now holds all steps' prose, not just the
             // last block.
+            // Empty-turn mitigation (#444, toggle OFF). If the turn burned all its
+            // steps WITHOUT ever producing text (every step's text is empty) and
+            // the model stopped because it hit the step cap, there is no answer to
+            // show — the lockdown used to force one. Append a synthetic marker as
+            // the trailing text so the exhausted-without-answer state is explicit
+            // to the user and, on replay, to the model next turn. `flushAssistant`
+            // takes this as the `inProgressText` trailing text arg (empty here
+            // otherwise). `stepCountIs(MAX_AGENT_STEPS)` surfaces as
+            // finishReason === 'tool-calls' (or a length/other cap), so we key off
+            // "no text produced" rather than a single finishReason string.
+            const producedText = (steps as StepLike[]).some((s) => s.text?.trim());
+            const stepExhausted = steps.length >= MAX_AGENT_STEPS;
+            const emptyTurnMarker =
+              !producedText && stepExhausted ? STEP_LIMIT_NO_ANSWER_MARKER : '';
             await finalizeAssistant(
-              flushAssistant(steps as StepLike[], '', 'completed', {
+              flushAssistant(steps as StepLike[], emptyTurnMarker, 'completed', {
                 finishReason: finishReason as string,
                 usage: totalUsage as StreamUsage,
                 contextTokens:
@@ -1252,6 +1402,30 @@ export class AiChatService implements OnModuleInit {
             await snapshotTurnEnd();
           },
           onAbort: async ({ steps }) => {
+            // #444: distinguish a degeneration abort (our internal controller) from
+            // a user Stop / disconnect. On degeneration we truncate the runaway tail
+            // before persist (so hundreds of KB of garbage never reach the DB /
+            // replay) and record it as an ERROR with a clear, distinguishable reason
+            // — NOT a bare 'aborted' (a user Stop) and NOT a swept 'streaming' (a
+            // server restart).
+            if (degenerationDetected) {
+              const truncated = truncateDegeneratedTail(inProgressText);
+              await finalizeAssistant(
+                flushAssistant(capturedSteps, truncated, 'error', {
+                  error: OUTPUT_DEGENERATION_ERROR,
+                  pageChanged,
+                }),
+              );
+              if (runId)
+                await runHooks?.onSettled?.(
+                  runId,
+                  'error',
+                  OUTPUT_DEGENERATION_ERROR,
+                );
+              await closeExternalClients();
+              await snapshotTurnEnd();
+              return;
+            }
             const partialChars =
               capturedSteps.reduce((n, s) => n + (s.text?.length ?? 0), 0) +
               inProgressText.length;
@@ -1637,6 +1811,17 @@ type StepLike = {
     toolName?: string;
     output?: unknown;
   }>;
+  // ai@6.0.134: a tool that THREW surfaces as a `tool-error` content part
+  // ({ type:'tool-error', toolCallId, toolName, input, error }), NOT as a
+  // `toolResults` entry (which holds only successes). Read from here so failed
+  // calls are persisted with their real error instead of being dropped.
+  content?: ReadonlyArray<{
+    type?: string;
+    toolCallId?: string;
+    toolName?: string;
+    input?: unknown;
+    error?: unknown;
+  }>;
 };
 
 /**
@@ -1739,6 +1924,26 @@ function compactValue(value: unknown, depth: number): unknown {
   return value;
 }
 
+/**
+ * Extract a bounded string message from a `tool-error` part's `error` field for
+ * persistence and history replay. The field may be an `Error`, a string, or an
+ * arbitrary object, so pull a message robustly. The result is passed through
+ * `compactValue` so a very long error honors the SAME truncation limits the file
+ * already applies to tool outputs (no new limit is introduced here).
+ */
+function normalizeToolError(error: unknown): string {
+  const message =
+    error instanceof Error
+      ? error.message
+      : typeof error === 'string'
+        ? error
+        : error != null &&
+            typeof (error as { message?: unknown }).message === 'string'
+          ? (error as { message: string }).message
+          : String(error);
+  return compactValue(message, 0) as string;
+}
+
 /**
  * Rebuild the FULL UIMessage `parts` for an assistant turn from the SDK steps,
  * so multi-turn history replays prior tool-calls/results to the model (not just
@@ -1771,6 +1976,14 @@ export function assistantParts(
     for (const r of step.toolResults ?? []) {
       if (r.toolCallId) resultsById.set(r.toolCallId, r.output);
     }
+    // Index this step's THROWN tool failures (ai@6 `tool-error` content parts)
+    // by tool call id, so a call that failed replays with its real error text.
+    const errorsById = new Map<string, unknown>();
+    for (const part of step.content ?? []) {
+      if (part.type === 'tool-error' && part.toolCallId) {
+        errorsById.set(part.toolCallId, part.error);
+      }
+    }
     for (const call of step.toolCalls ?? []) {
       if (!call.toolName || !call.toolCallId) continue;
       const hasResult = resultsById.has(call.toolCallId);
@@ -1783,9 +1996,21 @@ export function assistantParts(
           input: call.input,
           output: compactToolOutput(resultsById.get(call.toolCallId)),
         });
+      } else if (errorsById.has(call.toolCallId)) {
+        // The tool THREW: replay the REAL error so the model on the next turn
+        // knows WHY the call failed (and does not blindly repeat it). An
+        // output-error round-trips through convertToModelMessages as a balanced
+        // tool-call + tool-result, keeping the rebuilt history valid.
+        parts.push({
+          type: `tool-${call.toolName}`,
+          toolCallId: call.toolCallId,
+          state: 'output-error',
+          input: call.input,
+          errorText: normalizeToolError(errorsById.get(call.toolCallId)),
+        });
       } else {
-        // No paired result (e.g. aborted mid-step). Persisting a bare
-        // tool-call (input-available) would replay as an unpaired call and
+        // No paired result AND no tool-error (e.g. aborted mid-step). Persisting
+        // a bare tool-call (input-available) would replay as an unpaired call and
         // throw MissingToolResultsError on the next turn (convertToModelMessages
         // emits no tool-result for it). Emit a SYNTHETIC paired result instead:
         // an output-error round-trips through convertToModelMessages as a
@@ -2021,10 +2246,19 @@ export function serializeSteps(
   steps: ReadonlyArray<{
     toolCalls?: ReadonlyArray<{ toolName?: string; input?: unknown }>;
     toolResults?: ReadonlyArray<{ toolName?: string; output?: unknown }>;
+    content?: ReadonlyArray<{
+      type?: string;
+      toolName?: string;
+      error?: unknown;
+    }>;
   }>,
 ): unknown {
-  const calls: Array<{ toolName?: string; input?: unknown; output?: unknown }> =
-    [];
+  const calls: Array<{
+    toolName?: string;
+    input?: unknown;
+    output?: unknown;
+    error?: string;
+  }> = [];
   for (const step of steps ?? []) {
     for (const call of step.toolCalls ?? []) {
       calls.push({ toolName: call.toolName, input: call.input });
@@ -2032,6 +2266,18 @@ export function serializeSteps(
     for (const r of step.toolResults ?? []) {
       calls.push({ toolName: r.toolName, output: compactToolOutput(r.output) });
     }
+    // ai@6 surfaces a THROWN tool failure as a `tool-error` content part, NOT as
+    // a `toolResults` entry. Record it as its own paired element (mirroring how a
+    // successful result is appended) so the failure and its reason survive in the
+    // trace instead of leaving an orphaned call with no result.
+    for (const part of step.content ?? []) {
+      if (part.type === 'tool-error') {
+        calls.push({
+          toolName: part.toolName,
+          error: normalizeToolError(part.error),
+        });
+      }
+    }
   }
   return calls.length > 0 ? calls : null;
 }

apps/server/src/core/ai-chat/chat-markdown.util.ts

@@ -75,7 +75,7 @@ const LABELS: Record<
       searchPages: 'Searched pages',
       getPage: 'Read page',
       createPage: 'Created page',
-      updatePageContent: 'Updated page',
+      updatePageMarkdown: 'Updated page',
       renamePage: 'Renamed page',
       movePage: 'Moved page',
       deletePage: 'Deleted page (to trash)',
@@ -96,7 +96,7 @@ const LABELS: Record<
       searchPages: 'Искал по страницам',
       getPage: 'Прочитал страницу',
       createPage: 'Создал страницу',
-      updatePageContent: 'Обновил страницу',
+      updatePageMarkdown: 'Обновил страницу',
       renamePage: 'Переименовал страницу',
       movePage: 'Переместил страницу',
       deletePage: 'Удалил страницу (в корзину)',

apps/server/src/core/ai-chat/output-degeneration.spec.ts

@@ -0,0 +1,182 @@
+import {
+  hasRepeatedLineRun,
+  hasPeriodicTail,
+  isDegenerateOutput,
+  truncateDegeneratedTail,
+  REPEATED_LINES_THRESHOLD,
+  MIN_PERIOD_REPEATS,
+} from './output-degeneration';
+
+/**
+ * Unit tests for the token-degeneration detector (#444) — the sole anti-babble
+ * guard once the final-step lockdown is OFF. The two rules must fire on real
+ * degeneration (the "loadTools." incident, a no-newline repeat) and MUST NOT fire
+ * on legitimate long output (edit lists, tables, code).
+ */
+describe('hasRepeatedLineRun (rule 1: identical-line run)', () => {
+  it('POSITIVE: fires on "loadTools.\\n" repeated many times (the incident)', () => {
+    const text = 'Here is my plan.\n' + 'loadTools.\n'.repeat(300);
+    expect(hasRepeatedLineRun(text)).toBe(true);
+    expect(isDegenerateOutput(text)).toBe(true);
+  });
+
+  it('POSITIVE: fires at exactly the threshold', () => {
+    const text = 'x\n'.repeat(REPEATED_LINES_THRESHOLD);
+    expect(hasRepeatedLineRun(text)).toBe(true);
+  });
+
+  it('NEGATIVE: does NOT fire just below the threshold', () => {
+    // threshold-1 identical lines followed by a distinct line.
+    const text = 'x\n'.repeat(REPEATED_LINES_THRESHOLD - 1) + 'done\n';
+    expect(hasRepeatedLineRun(text)).toBe(false);
+  });
+
+  it('NEGATIVE: a long edit list of DISTINCT lines never trips', () => {
+    const lines: string[] = [];
+    for (let i = 0; i < 200; i++) lines.push(`- edited section ${i}: fixed typo`);
+    const text = lines.join('\n');
+    expect(hasRepeatedLineRun(text)).toBe(false);
+    expect(isDegenerateOutput(text)).toBe(false);
+  });
+
+  it('NEGATIVE: a markdown table with blank separators does not trip', () => {
+    // Repeated identical rows are unusual, but blank lines break any run.
+    const block = ['| a | b |', '| - | - |', '', '| a | b |', ''];
+    const text = Array.from({ length: 60 }, () => block.join('\n')).join('\n');
+    expect(hasRepeatedLineRun(text)).toBe(false);
+  });
+
+  it('NEGATIVE: blank lines do NOT count toward a run', () => {
+    const text = '\n'.repeat(100);
+    expect(hasRepeatedLineRun(text)).toBe(false);
+  });
+});
+
+describe('hasPeriodicTail (rule 2: no-newline suffix periodicity)', () => {
+  it('POSITIVE: fires on a single char repeated with no newlines', () => {
+    const text = 'answer: ' + 'a'.repeat(500);
+    expect(hasPeriodicTail(text)).toBe(true);
+    expect(isDegenerateOutput(text)).toBe(true);
+  });
+
+  it('POSITIVE: fires on a multi-char block repeat with no newlines', () => {
+    const text = 'prefix ' + 'abcdef'.repeat(100);
+    expect(hasPeriodicTail(text)).toBe(true);
+  });
+
+  it('POSITIVE: at least MIN_PERIOD_REPEATS repeats of a small block', () => {
+    const text = 'go'.repeat(MIN_PERIOD_REPEATS);
+    expect(hasPeriodicTail(text)).toBe(true);
+  });
+
+  it('NEGATIVE: prose does not look periodic', () => {
+    const text =
+      'The quick brown fox jumps over the lazy dog while the sun sets slowly ' +
+      'behind the distant mountains and the river winds through the valley below.';
+    expect(hasPeriodicTail(text)).toBe(false);
+    expect(isDegenerateOutput(text)).toBe(false);
+  });
+
+  it('NEGATIVE: a long code block is not flagged', () => {
+    const code = `
+function compute(values) {
+  let total = 0;
+  for (const v of values) {
+    total += v * 2;
+  }
+  return total / values.length;
+}
+export const helper = (x) => x + 1;
+const config = { retries: 3, timeout: 5000, backoff: 'exp' };
+`.repeat(3);
+    expect(isDegenerateOutput(code)).toBe(false);
+  });
+
+  it('NEGATIVE: a short string well under the repeat count is safe', () => {
+    expect(hasPeriodicTail('ababab')).toBe(false);
+  });
+
+  // Regression (#444): a trivial single-char period (p===1) must NOT flag
+  // legitimate divider/underline/whitespace runs. These are common in real
+  // model output and previously false-positived at ~20 identical chars, aborting
+  // the run and truncating output. They must all be treated as clean.
+  it('NEGATIVE: a markdown horizontal rule is not flagged', () => {
+    const text = 'text\n' + '-'.repeat(40);
+    expect(hasPeriodicTail(text)).toBe(false);
+    expect(isDegenerateOutput(text)).toBe(false);
+  });
+
+  it('NEGATIVE: a setext heading underline is not flagged', () => {
+    const text = 'Title\n' + '='.repeat(30);
+    expect(hasPeriodicTail(text)).toBe(false);
+    expect(isDegenerateOutput(text)).toBe(false);
+  });
+
+  it('NEGATIVE: a box-drawing divider with no trailing newline is not flagged', () => {
+    const text = 'done ' + '─'.repeat(50);
+    expect(hasPeriodicTail(text)).toBe(false);
+    expect(isDegenerateOutput(text)).toBe(false);
+  });
+
+  it('NEGATIVE: trailing spaces are not flagged', () => {
+    const text = 'answer' + ' '.repeat(40);
+    expect(hasPeriodicTail(text)).toBe(false);
+    expect(isDegenerateOutput(text)).toBe(false);
+  });
+
+  // TRIVIAL_MIN_REPEATS boundary (#444 review). The monochar-tail branch fires at
+  // EXACTLY 60 identical trailing chars (`run >= TRIVIAL_MIN_REPEATS`), so 59 is
+  // clean and 60 trips. These pin the `>=` and MUST fail if the comparison is
+  // flipped to `>` (the surviving mutation). The value 60 is HARD-CODED here on
+  // purpose: TRIVIAL_MIN_REPEATS is a private constant and the assert must lock
+  // the literal boundary the reviewer named, not track a constant edit.
+  it('NEGATIVE: 59 identical trailing chars is one below the monochar threshold', () => {
+    expect(hasPeriodicTail('x'.repeat(59))).toBe(false);
+    expect(isDegenerateOutput('x'.repeat(59))).toBe(false);
+  });
+
+  it('POSITIVE: 60 identical trailing chars hits the monochar threshold exactly', () => {
+    // Fails if `run >= TRIVIAL_MIN_REPEATS` is mutated to `run > …`.
+    expect(hasPeriodicTail('x'.repeat(60))).toBe(true);
+    expect(isDegenerateOutput('x'.repeat(60))).toBe(true);
+  });
+
+  // Positive counterparts: a GENUINE single-char runaway (hundreds+ of repeats)
+  // and the real incident (period>=2, "loadTools." ×N) must still fire.
+  it('POSITIVE: a genuine single-char runaway is still flagged', () => {
+    const text = 'x'.repeat(5000);
+    expect(hasPeriodicTail(text)).toBe(true);
+    expect(isDegenerateOutput(text)).toBe(true);
+  });
+
+  it('POSITIVE: the "loadTools." incident (period>=2) is still flagged', () => {
+    const text = 'loadTools.'.repeat(500);
+    expect(hasPeriodicTail(text)).toBe(true);
+    expect(isDegenerateOutput(text)).toBe(true);
+  });
+});
+
+describe('truncateDegeneratedTail', () => {
+  it('collapses a repeated-line loop to a few reps + marker', () => {
+    const text = 'plan\n' + 'loadTools.\n'.repeat(20000);
+    const out = truncateDegeneratedTail(text);
+    expect(out.length).toBeLessThan(text.length);
+    expect(out).toContain('output truncated');
+    // Keeps the leading context and a few loop reps.
+    expect(out).toContain('plan');
+    expect((out.match(/loadTools\./g) ?? []).length).toBeLessThan(10);
+  });
+
+  it('collapses a no-newline periodic loop to a few blocks + marker', () => {
+    const text = 'answer: ' + 'xy'.repeat(50000);
+    const out = truncateDegeneratedTail(text);
+    expect(out.length).toBeLessThan(text.length);
+    expect(out).toContain('output truncated');
+    expect(out).toContain('answer:');
+  });
+
+  it('returns non-degenerate text unchanged (by identity)', () => {
+    const text = 'A perfectly normal, finished assistant answer.';
+    expect(truncateDegeneratedTail(text)).toBe(text);
+  });
+});

apps/server/src/core/ai-chat/output-degeneration.ts

@@ -0,0 +1,189 @@
+/**
+ * Token-degeneration detector for the in-app agent stream (#444).
+ *
+ * When the final-step lockdown is OFF (the new default) there is no toolChoice
+ * override to strip the model's tools mid-work, so the anti-babble safety net is
+ * this detector. It watches the accumulating assistant text and, on a runaway
+ * repetition loop (the 255KB "loadTools." incident), aborts the run.
+ *
+ * Both rules are PURE functions of the text tail so they are cheap to run every
+ * few KB and are unit-testable in isolation. They operate on the TAIL only
+ * (`TAIL_WINDOW` chars) so the cost is bounded regardless of how long the turn is.
+ */
+
+/** How many trailing chars of the accumulated text the rules inspect. */
+export const TAIL_WINDOW = 3000;
+
+/** Rule 1 threshold: minimum consecutive identical non-empty lines to trigger. */
+export const REPEATED_LINES_THRESHOLD = 25;
+
+/** Rule 2: maximum length of a repeating block considered for periodicity. */
+export const MAX_PERIOD_LEN = 150;
+
+/** Rule 2: minimum number of consecutive block repeats to trigger. */
+export const MIN_PERIOD_REPEATS = 20;
+
+/**
+ * Rule 1 — ≥`REPEATED_LINES_THRESHOLD` consecutive IDENTICAL non-empty lines at
+ * the tail. Catches the classic newline-delimited loop ("loadTools.\n" ×N).
+ * Blank lines break a run (a table / list with blank separators never trips it);
+ * a run of ordinary distinct lines (an edit list, code) never reaches the count.
+ *
+ * NB: `REPEATED_LINES_THRESHOLD` (25) is only THIS rule's own trigger, not the
+ * effective floor for detecting a repeated-line loop. In practice a newline-
+ * delimited repeat also has a fixed period (line + '\n'), so rule 2 catches it
+ * via periodicity at `MIN_PERIOD_REPEATS` (20) repeats — the two rules combine
+ * (see `isDegenerateOutput`), so the effective lower bound for a short identical
+ * line loop is ~20, not 25. Pure.
+ */
+export function hasRepeatedLineRun(
+  text: string,
+  threshold = REPEATED_LINES_THRESHOLD,
+): boolean {
+  const tail = text.length > TAIL_WINDOW ? text.slice(-TAIL_WINDOW) : text;
+  const lines = tail.split('\n');
+  let run = 1;
+  let prev: string | null = null;
+  for (const line of lines) {
+    if (line.length > 0 && line === prev) {
+      run += 1;
+      if (run >= threshold) return true;
+    } else {
+      run = 1;
+    }
+    prev = line;
+  }
+  return false;
+}
+
+/**
+ * Rule 2 — cheap suffix-periodicity check: the tail ends in
+ * ≥`MIN_PERIOD_REPEATS` back-to-back repeats of a single block of length
+ * ≤`MAX_PERIOD_LEN`. Catches a no-newline repeat ("abcabcabc…") the line rule
+ * misses. For each candidate period length p we verify the last `repeats*p`
+ * chars are p-periodic; we stop at the smallest p that satisfies the repeat
+ * count. Bounded by MAX_PERIOD_LEN × TAIL_WINDOW comparisons — negligible. Pure.
+ */
+export function hasPeriodicTail(
+  text: string,
+  maxPeriod = MAX_PERIOD_LEN,
+  minRepeats = MIN_PERIOD_REPEATS,
+): boolean {
+  const tail = text.length > TAIL_WINDOW ? text.slice(-TAIL_WINDOW) : text;
+  const n = tail.length;
+  // Not even the shortest possible loop fits in the tail.
+  if (n < minRepeats) return false;
+  // A tail of ONE repeated char (a "trivial period") is common in LEGIT output —
+  // markdown rules (----/====), setext underlines, box-drawing dividers,
+  // trailing spaces routinely produce 20–50 identical chars. Such a run is
+  // p-periodic for EVERY p, so it would otherwise trip the block rule at p>=2
+  // too, not just p===1. We therefore split the check: a monochar tail needs far
+  // more repeats (a real single-char babble loop produces hundreds-to-thousands;
+  // 60 is well above any realistic divider yet a fifth of TAIL_WINDOW), while a
+  // genuine multi-char block repeat (>=2 distinct chars, e.g. the "loadTools."
+  // incident, period ~10) keeps the normal MIN_PERIOD_REPEATS threshold.
+  const TRIVIAL_MIN_REPEATS = 60;
+
+  // Monochar-tail check (the trivial-period case): count the trailing run of one
+  // identical char and require TRIVIAL_MIN_REPEATS of them.
+  {
+    const last = tail[n - 1];
+    let run = 1;
+    for (let i = n - 2; i >= 0 && tail[i] === last; i--) run++;
+    if (run >= TRIVIAL_MIN_REPEATS) return true;
+  }
+
+  const maxP = maxPeriod;
+  for (let p = 2; p <= maxP; p++) {
+    // Verify the last (minRepeats*p) chars are p-periodic AND not monochar (a
+    // monochar span is the trivial case handled above, so skip it here to avoid
+    // re-flagging a legit divider at a composite period).
+    const span = minRepeats * p;
+    // Not enough tail to hold this many repeats of this period.
+    if (span > n) continue;
+    const start = n - span;
+    let periodic = true;
+    let multiChar = false;
+    for (let i = n - 1; i >= start + p; i--) {
+      if (tail[i] !== tail[i - p]) {
+        periodic = false;
+        break;
+      }
+    }
+    if (!periodic) continue;
+    // Confirm the block itself has >=2 distinct chars (else it's monochar).
+    for (let i = start + 1; i < n; i++) {
+      if (tail[i] !== tail[start]) {
+        multiChar = true;
+        break;
+      }
+    }
+    if (multiChar) return true;
+  }
+  return false;
+}
+
+/**
+ * Combined guard used by the stream's onChunk: true when EITHER rule fires.
+ * Pure — the caller owns the abort side effect.
+ */
+export function isDegenerateOutput(text: string): boolean {
+  return hasRepeatedLineRun(text) || hasPeriodicTail(text);
+}
+
+/**
+ * Truncate a degenerated tail before persist so hundreds of KB of garbage never
+ * reach the DB / replay (#444). Keeps everything up to and including the FIRST
+ * `keepRepeats` repeats of the detected loop, then appends a short marker. If no
+ * loop is detected the text is returned unchanged (by identity).
+ *
+ * Implementation: find the shortest tail period (same check as hasPeriodicTail),
+ * keep the prefix before the loop plus `keepRepeats` copies of the block, drop
+ * the rest. This is best-effort cosmetic trimming; correctness does not depend on
+ * finding the exact minimal loop. Pure.
+ */
+export function truncateDegeneratedTail(
+  text: string,
+  keepRepeats = 3,
+): string {
+  const marker = '\n…[output truncated: repeated token loop detected]';
+  // Try the line rule first: collapse a long run of identical lines.
+  const lines = text.split('\n');
+  let runStart = -1;
+  let run = 1;
+  for (let i = 1; i < lines.length; i++) {
+    if (lines[i].length > 0 && lines[i] === lines[i - 1]) {
+      if (run === 1) runStart = i - 1;
+      run += 1;
+      if (run >= REPEATED_LINES_THRESHOLD) {
+        const kept = lines.slice(0, runStart + keepRepeats).join('\n');
+        return kept + marker;
+      }
+    } else {
+      run = 1;
+      runStart = -1;
+    }
+  }
+
+  // Fall back to periodicity over the whole string (bounded by the same block
+  // length). Find the smallest period that makes the SUFFIX highly repetitive.
+  const n = text.length;
+  const maxP = Math.min(MAX_PERIOD_LEN, Math.floor(n / MIN_PERIOD_REPEATS));
+  for (let p = 1; p <= maxP; p++) {
+    // Count how many trailing p-blocks are periodic.
+    let reps = 1;
+    let i = n - 1;
+    for (; i >= p; i--) {
+      if (text[i] !== text[i - p]) break;
+    }
+    // The loop above walks over the periodic suffix; its length is (n-1 - i).
+    const periodicLen = n - 1 - i;
+    reps = Math.floor(periodicLen / p) + 1;
+    if (reps >= MIN_PERIOD_REPEATS) {
+      const loopStart = n - reps * p; // start of the fully-periodic suffix
+      const kept = text.slice(0, loopStart + keepRepeats * p);
+      return kept + marker;
+    }
+  }
+  return text;
+}