feat(share): Stage B — "approved" publish-only-the-saved-version mode (#370 )

A share can now be published in 'approved' mode: public readers by URL see the last manually-saved version (page_history.kind='manual') instead of the live draft. The content swap lives in the single canonical resolver resolveReadableSharePage, so EVERY public read path is frozen consistently — the shared-page view, the SEO controller, AND the share assistant's page-read tool (owner decision: a visitor and the assistant see the same bytes). Swaps only content+title; page.id/workspaceId stay LIVE so attachment tokens keep minting for the right owner. MVP residue kept live: the assistant's page LIST/TREE tools and transclusions. - migration 20260712T130000: shares.published_mode varchar(20) NOT NULL DEFAULT 'live' (additive, standalone; existing shares stay live) - db.d.ts: publishedMode on Shares (Share/Insertable/Updatable derive) - page-history.repo: findLatestByPageIdAndKind(pageId, kind, {includeContent}) - share.repo: thread publishedMode through baseFields/insert/update - share.service.getShareForPage: 4-point CTE threading (anchor + union + returned object + repo allowlist) — type-guarded, so dropping any point fails the build/tests - createShare/updateShare: accept publishedMode; reject approved+includeSubPages (BadRequestException); auto-mint the first manual baseline ON ENABLE - share.dto: publishedMode @IsOptional @IsIn(['live','approved']) - client: "Publish only the saved version" toggle (XOR with sub-pages), version caption + "unsaved changes newer than the published version" hint; share types/api carry publishedMode - tests: resolve-swap (content+title swapped, id+workspaceId preserved), assistant getSharePage sees frozen content, getShareForPage threading (direct + descendant), baseline auto-create, XOR reject, migration up/down Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Merge pull request 'fix(prosemirror-markdown): литеральный <br> в тексте экранируется, не становится hardBreak (#554 )' (#560 ) from fix/554-literal-br into develop
2026-07-12 19:08:50 +03:00 · 2026-07-12 18:57:02 +03:00 · 2026-07-12 18:56:49 +03:00 · 2026-07-12 18:01:07 +03:00 · 2026-07-12 18:01:07 +03:00 · 2026-07-12 17:58:21 +03:00
139 changed files with 12415 additions and 1707 deletions
@@ -463,6 +463,7 @@ Vite SPA. Code is organized by feature under `apps/client/src/features/*` (mirro
 - The editor is Tiptap; shared node/mark extensions live in `packages/editor-ext` and are imported by **both the client and the server** (collaboration, schema, `canonicalizeFootnotes`) — editor schema changes often need to be made in `editor-ext`, not just the client. Server-side markdown import/export no longer lives in `editor-ext`: it goes through the canonical converter (#345, see below). The ProseMirror↔Markdown converter and its Docmost schema mirror now live in a SINGLE package, `@docmost/prosemirror-markdown` (#293), consumed by `mcp`, `git-sync`, `apps/server` (#345), and `apps/client` (#347) — do NOT reintroduce a per-package copy. The client uses the package's `browser` entry (`@docmost/prosemirror-markdown/browser`): markdown paste (`markdown-clipboard.ts`), copy-as-markdown, and AI-chat rendering now all go through the canonical converter, so the hand-written `marked`/`turndown` markdown layer that used to live in `editor-ext` was deleted (#347). The browser entry runs the HTML→DOM stage on the native `DOMParser`, so jsdom stays out of the client bundle. `editor-ext` is the upstream source of the Tiptap schema; the package's `docmost-schema.ts` mirrors it and a serializer-contract test (`packages/prosemirror-markdown/test/serializer-contract.test.ts`) guards the boundary (every schema node must have a converter case), so a drift surfaces as a failing test rather than silent divergence. For the converter's property-testing and counterexample→fixture process (P1–P4 invariants, the `PROPERTY_SEED`/`PROPERTY_NUM_RUNS` knobs, and the nightly fuzz workflow), see `packages/prosemirror-markdown/README.md`.
 - API access goes through `apps/client/src/lib/api-client.ts` (axios). The `@` alias maps to `apps/client/src`.
 - Runtime config is injected at build time by `vite.config.ts` via `define` (`APP_URL`, `COLLAB_URL`, `APP_VERSION`, …) — these come from the root `.env`, not from `import.meta.env`.
+- The build also emits `client/dist/version.json` (`{"version": …}`) from a small `vite.config.ts` plugin using the **same** `appVersion` that feeds `define.APP_VERSION`, so the file and the baked-in bundle version are identical by construction. The server reads it at startup (`ws.gateway.ts` via `readClientBuildVersion`/`resolveClientDistPath`) and announces it to each socket on connect (`app-version` event) so a tab left open across a redeploy can guard-reload before hitting a stale chunk (version-coherence). No runtime env / Dockerfile change — the file already ships in `client/dist`; missing/empty file ⇒ feature inert.

 ## Conventions

@@ -142,6 +142,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  snapshots switched from a fixed interval to a trailing idle-flush with a
  max-wait ceiling, and a boundary snapshot is pinned whenever the editing source
  changes (e.g. a person's edits followed by the AI agent). (#370)
+- **Open tabs pick up a new deploy on their own.** After the server is
+  redeployed while a tab is left open for hours, the tab now learns the new
+  build version over the existing WebSocket (announced per-connect, so a natural
+  reconnect delivers it) and shows a "A new version is available" banner with an
+  Update button. To avoid dropping a half-written comment or form, the tab is
+  not reloaded when you merely switch away from it; instead it auto-reloads at
+  the next safe point — the next in-app navigation (or immediately if you click
+  Update) — before it can hit a stale lazy-loaded chunk. At most one automatic
+  reload happens per 5-minute window, shared with the existing chunk-load
+  recovery, so a permanent version skew degrades to the banner rather than a
+  reload loop while a second deploy in the same tab still recovers. When the
+  build carries no version info the feature stays inert. (#481)

 - **Place several images side by side in a row.** A new "Inline (side by
  side)" alignment mode in the image bubble menu renders consecutive inline
@@ -392,6 +404,25 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  `@docmost/token-estimate` package) so they can never diverge. Deferred-tool
  activation is also cached in the chat metadata to avoid re-resolving it each
  turn. (#490)
+- **Cyrillic (and any non-ASCII) draw.io labels no longer turn into mojibake
+  when a diagram is opened in the draw.io editor.** Agent-created diagrams
+  (`drawioCreate`) and Confluence-imported diagrams stored their model in the
+  SVG's `content=` attribute as base64; the draw.io editor decodes that via
+  Latin-1 `atob` (no UTF-8 step), so every non-ASCII char (e.g. `Старт-бит`,
+  `ё`, `—`) split into garbage and the editor's autosave then persisted the
+  corrupted model, breaking the page preview too. Both write paths
+  (`buildDrawioSvg`, the import service's `createDrawioSvg`) now write `content=`
+  as XML-entity-escaped mxfile XML — draw.io's own native form, decoded by the
+  DOM as UTF-8 — so labels open intact. The decoder reads both the new
+  entity-encoded form and the old base64 form, so existing diagrams still open.
+  *Healing pre-fix diagrams:* only a diagram that still holds its original
+  (correct-UTF-8) base64 — i.e. one not yet opened/autosaved in the draw.io
+  editor — can be repaired in place by `drawioGet` → `drawioUpdate` with the
+  same XML (rewrites the attachment in the new form); no migration script is
+  needed. A diagram that was already opened in the editor persisted the
+  mojibake at rest, so `drawioGet` reads the already-corrupted text and
+  `drawioUpdate` faithfully rewrites it — that text is lost and is not
+  recoverable by a rewrite. (#507)
 - **A chat with one malformed message part no longer 500s on every turn, and a
  failed send no longer duplicates the user's message.** Incoming client parts
  are now whitelisted to `text` (a forged tool-result part can no longer reach
@@ -1,4 +1,5 @@
 {
+  "A new version is available": "A new version is available",
  "Account": "Account",
  "Active": "Active",
  "Add": "Add",
@@ -239,6 +240,8 @@
  "Comment re-opened successfully": "Comment re-opened successfully",
  "Comment unresolved successfully": "Comment unresolved successfully",
  "Failed to resolve comment": "Failed to resolve comment",
+  "Failed to re-open comment": "Failed to re-open comment",
+  "Comment no longer exists": "Comment no longer exists",
  "Resolve comment": "Resolve comment",
  "Unresolve comment": "Unresolve comment",
  "Resolve Comment Thread": "Resolve Comment Thread",
@@ -1427,5 +1430,20 @@
  "Boundary": "Boundary",
  "Autosave": "Autosave",
  "Only versions": "Only versions",
-  "No saved versions yet.": "No saved versions yet."
+  "No saved versions yet.": "No saved versions yet.",
+  "Time worked on this article": "Time worked on this article",
+  "Show time worked on this page": "Show time worked on this page",
+  "Estimated time worked (inactivity gap {{gap}} min)": "Estimated time worked (inactivity gap {{gap}} min)",
+  "Estimate · timezone {{tz}} · inactivity gap {{gap}} min": "Estimate · timezone {{tz}} · inactivity gap {{gap}} min",
+  "No editing activity recorded yet.": "No editing activity recorded yet.",
+  "× {{count}} days without edits": "× {{count}} days without edits",
+  "agent: {{value}}": "agent: {{value}}",
+  "Work": "Work",
+  "Agent": "Agent",
+  "≈ {{hours}}h {{minutes}}m": "≈ {{hours}}h {{minutes}}m",
+  "≈ {{hours}}h": "≈ {{hours}}h",
+  "≈ {{minutes}}m": "≈ {{minutes}}m",
+  "{{hours}}h {{minutes}}m": "{{hours}}h {{minutes}}m",
+  "{{hours}}h": "{{hours}}h",
+  "{{minutes}}m": "{{minutes}}m"
 }
@@ -1,4 +1,5 @@
 {
+  "A new version is available": "Доступна новая версия",
  "Account": "Аккаунт",
  "Active": "Активный",
  "Add": "Добавить",
@@ -239,6 +240,8 @@
  "Comment re-opened successfully": "Комментарий успешно открыт повторно",
  "Comment unresolved successfully": "Комментарий успешно переведён в нерешённые",
  "Failed to resolve comment": "Не удалось разрешить комментарий",
+  "Failed to re-open comment": "Не удалось переоткрыть комментарий",
+  "Comment no longer exists": "Комментарий больше не существует",
  "Resolve comment": "Решить комментарий",
  "Unresolve comment": "Снять статус решённого с комментария",
  "Resolve Comment Thread": "Решить ветку комментариев",
@@ -1442,5 +1445,20 @@
  "Boundary": "Граница",
  "Autosave": "Автосейв",
  "Only versions": "Только версии",
-  "No saved versions yet.": "Пока нет сохранённых версий."
+  "No saved versions yet.": "Пока нет сохранённых версий.",
+  "Time worked on this article": "Время работы над статьёй",
+  "Show time worked on this page": "Показать время работы над страницей",
+  "Estimated time worked (inactivity gap {{gap}} min)": "Оценка времени работы (порог паузы {{gap}} мин)",
+  "Estimate · timezone {{tz}} · inactivity gap {{gap}} min": "Оценка · таймзона {{tz}} · порог паузы {{gap}} мин",
+  "No editing activity recorded yet.": "Правок пока нет.",
+  "× {{count}} days without edits": "× {{count}} дн. без правок",
+  "agent: {{value}}": "агент: {{value}}",
+  "Work": "Работа",
+  "Agent": "Агент",
+  "≈ {{hours}}h {{minutes}}m": "≈ {{hours}} ч {{minutes}} мин",
+  "≈ {{hours}}h": "≈ {{hours}} ч",
+  "≈ {{minutes}}m": "≈ {{minutes}} мин",
+  "{{hours}}h {{minutes}}m": "{{hours}} ч {{minutes}} м",
+  "{{hours}}h": "{{hours}} ч",
+  "{{minutes}}m": "{{minutes}} м"
 }
@@ -1,5 +1,5 @@
 import { describe, it, expect } from "vitest";
-import { isChunkLoadError, shouldAutoReload } from "./chunk-load-error-boundary";
+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
@@ -35,31 +35,3 @@ describe("isChunkLoadError", () => {
    expect(isChunkLoadError(err)).toBe(false);
  });
 });
-
-// The window gate replaces the old one-shot flag: it must permit recovery across
-// several deploys in one tab (each > window apart) while still stopping an infinite
-// reload loop when a lazy chunk is permanently broken (a second failure < window).
-describe("shouldAutoReload", () => {
-  const WINDOW = 5 * 60 * 1000;
-  const NOW = 1_000_000_000_000;
-
-  it("allows a reload when we have never auto-reloaded", () => {
-    expect(shouldAutoReload(NOW, null, WINDOW)).toBe(true);
-  });
-
-  it("allows a reload when the last one was 6 minutes ago (outside the window)", () => {
-    expect(shouldAutoReload(NOW, NOW - 6 * 60 * 1000, WINDOW)).toBe(true);
-  });
-
-  it("blocks a reload when the last one was 1 minute ago (inside the window)", () => {
-    expect(shouldAutoReload(NOW, NOW - 1 * 60 * 1000, WINDOW)).toBe(false);
-  });
-
-  it("blocks a reload exactly at the window boundary (not strictly older)", () => {
-    expect(shouldAutoReload(NOW, NOW - WINDOW, WINDOW)).toBe(false);
-  });
-
-  it("allows a reload when the stored timestamp is unparseable (NaN)", () => {
-    expect(shouldAutoReload(NOW, NaN, WINDOW)).toBe(true);
-  });
-});
@@ -1,26 +1,11 @@
 import { ReactNode } from "react";
 import { ErrorBoundary } from "react-error-boundary";
 import { Button, Center, Stack, Text } from "@mantine/core";
-
-// sessionStorage key holding the epoch-ms timestamp of the last automatic reload.
-const RELOAD_AT_KEY = "chunk-reload-at";
-// Allow at most one automatic reload per this window. A stale-deploy 404 is cured
-// by a single reload, so anything inside the window is treated as a reload loop
-// (permanently-broken chunk) and falls through to the manual UI. A window (rather
-// than a one-shot flag) lets a SECOND deploy in the same tab's lifetime recover too.
-const RELOAD_WINDOW_MS = 5 * 60 * 1000;
-
-// Pure window decision, unit-tested in isolation: auto-reload only if we have never
-// auto-reloaded (lastReloadAt null/NaN) or the last one was strictly older than the
-// window. Anything inside the window is suppressed to break an infinite reload loop.
-export function shouldAutoReload(
-  now: number,
-  lastReloadAt: number | null,
-  windowMs: number,
-): boolean {
-  if (lastReloadAt === null || Number.isNaN(lastReloadAt)) return true;
-  return now - lastReloadAt > windowMs;
-}
+import {
+  hasAutoReloaded,
+  markAutoReloaded,
+  recordReloadBreadcrumb,
+} from "@/lib/reload-guard";

 // Heuristic detection of a failed dynamic import. Since the code-splitting work,
 // every route (plus Aside / AiChatWindow) is React.lazy: when a new deploy
@@ -39,24 +24,26 @@ export function isChunkLoadError(error: unknown): boolean {
  );
 }

-function handleError(error: unknown) {
+// Exported for tests: the reactive chunk-load reload decision, so the shared
+// window budget (invariant: ≤1 auto-reload per window across this path AND the
+// proactive version-coherence path) can be exercised against the real guard.
+export function handleError(error: unknown) {
  if (!isChunkLoadError(error)) return;
  // A stale-chunk 404 is cured by a full reload that re-fetches index.html and
-  // the new chunk manifest. Auto-reload at most once per RELOAD_WINDOW_MS: this
-  // recovers across multiple deploys in a single tab's lifetime, yet a
-  // permanently-broken lazy chunk (which would loop) is stopped after the first
-  // reload and falls through to the manual recovery UI below.
-  try {
-    const raw = sessionStorage.getItem(RELOAD_AT_KEY);
-    const lastReloadAt = raw === null ? null : Number.parseInt(raw, 10);
-    const now = Date.now();
-    if (!shouldAutoReload(now, lastReloadAt, RELOAD_WINDOW_MS)) return;
-    sessionStorage.setItem(RELOAD_AT_KEY, String(now));
-  } catch {
-    // sessionStorage unavailable (private mode / disabled): skip the automatic
-    // reload rather than risk an unguarded loop; the fallback UI still recovers.
-    return;
-  }
+  // the new chunk manifest. Auto-reload at most once per window via the SHARED
+  // window-based reload guard (see @/lib/reload-guard — the same budget the
+  // proactive version-coherence path consumes, so a mismatch that arrives on
+  // both paths reloads at most once per window across BOTH). This recovers
+  // across multiple deploys in a single tab's lifetime, yet a permanently-broken
+  // lazy chunk (which would loop) is stopped after the first reload and falls
+  // through to the manual recovery UI below. If the shared budget is already
+  // spent this window, or the stamp write fails (storage unavailable), we return
+  // without reloading rather than risk a loop.
+  if (hasAutoReloaded()) return;
+  if (!markAutoReloaded()) return;
+  // Trace before the reload clears the console (same diagnostic breadcrumb the
+  // proactive version-coherence path writes, tagged with this path).
+  recordReloadBreadcrumb({ path: "chunk-boundary" });
  window.location.reload();
 }

@@ -1254,4 +1254,88 @@ describe("ChatThread — live reconnect + stalled", () => {
    });
    expect(onResumeFallback).toHaveBeenCalledWith(false); // POLL_IDLE_CAP -> idle -> disarm
  });
+
+  it("#541: getRun HANGS on a live disconnect — the timeout race still enters reconnect (no silent freeze in `streaming`)", async () => {
+    // MUTATION-VERIFY: revert the race to a bare `getRun(cid).then/.catch` and this
+    // reddens — a HUNG (never-settling, NOT rejected) getRun leaves the FSM stuck in
+    // `streaming` with no reconnect banner and no poll (the axios client sets no
+    // request timeout, and the stalled-idle cap only arms AFTER reconnecting/polling).
+    renderLive();
+    h.state.getRun.mockReset();
+    h.state.getRun.mockReturnValue(new Promise(() => {})); // getRun HANGS forever
+    await disconnect(); // live partial = liveMsg (id "a2")
+    expect(h.state.getRun).toHaveBeenCalledWith("c1");
+    // BEFORE the bound fires the FSM is still in the live turn — the very freeze bug.
+    expect(screen.queryByText(/reconnecting/i)).toBeNull();
+    // The recovery-start bound fires -> the SAME fallback as the reject path.
+    act(() => {
+      vi.advanceTimersByTime(4_000);
+    });
+    expect(screen.getByText(/reconnecting/i)).toBeTruthy();
+    // The live partial (a2) was DROPPED from the store (replay-from-start, no stale
+    // tail-apply base). Mirrors the getRun-REJECT test's inspection.
+    const removedLivePartial = (
+      h.state.setMessages as unknown as {
+        mock: { calls: [unknown][] };
+      }
+    ).mock.calls.some(([updater]) => {
+      if (typeof updater !== "function") return false;
+      const out = (updater as (p: { id: string }[]) => { id: string }[])([
+        { id: "a2" },
+        { id: "u1" },
+      ]);
+      return !out.some((m) => m.id === "a2");
+    });
+    expect(removedLivePartial).toBe(true);
+    // ...and the anchor was NULLED -> replay-from-start (no ?anchor=&n= over the partial).
+    advanceToAttempt(1);
+    expect(h.state.resumeStream).toHaveBeenCalledTimes(1);
+    expect(h.state.transport!.prepareReconnectToStreamRequest!().api).toBe(
+      "/api/ai-chat/runs/c1/stream",
+    );
+  });
+
+  it("#541: a getRun resolve AFTER the timeout already fired is IGNORED (no double reconnect, no stale re-seed)", async () => {
+    // The timeout wins first and enters the ladder via replay-from-start. When the
+    // hung getRun FINALLY answers, its late `.then` must be a full no-op: it must not
+    // re-seed the store from the (now stale) persisted row, must not re-set the
+    // anchor, and must not re-enter reconnect. The local `settled` flag makes the
+    // resolve/reject/timeout branches mutually exclusive.
+    // MUTATION-VERIFY: drop the `settled` guard (let the late `.then` run) and the
+    // late re-seed re-sets the anchor (URL regains ?anchor=a2&n=3) + calls setMessages.
+    renderLive();
+    let resolveGetRun!: (v: unknown) => void;
+    h.state.getRun.mockReset();
+    h.state.getRun.mockReturnValue(
+      new Promise((r) => {
+        resolveGetRun = r;
+      }),
+    );
+    await disconnect();
+    act(() => {
+      vi.advanceTimersByTime(4_000); // bound fires -> replay-from-start, reconnecting
+    });
+    expect(screen.getByText(/reconnecting/i)).toBeTruthy();
+    advanceToAttempt(1);
+    expect(h.state.resumeStream).toHaveBeenCalledTimes(1);
+    // Anchor is null -> replay-from-start URL (the pre-condition the late resolve must
+    // not undo).
+    expect(h.state.transport!.prepareReconnectToStreamRequest!().api).toBe(
+      "/api/ai-chat/runs/c1/stream",
+    );
+    const setMessagesCallsBefore = h.state.setMessages.mock.calls.length;
+    // NOW the hung getRun finally resolves with a persisted anchor (id a2, steps 3).
+    await act(async () => {
+      resolveGetRun(persistedAnchor());
+      await Promise.resolve();
+    });
+    // The late resolve did NOT re-seed the store...
+    expect(h.state.setMessages.mock.calls.length).toBe(setMessagesCallsBefore);
+    // ...did NOT re-set the anchor (URL stays replay-from-start, no ?anchor=&n=)...
+    expect(h.state.transport!.prepareReconnectToStreamRequest!().api).toBe(
+      "/api/ai-chat/runs/c1/stream",
+    );
+    // ...and did NOT trigger a fresh reconnect attach.
+    expect(h.state.resumeStream).toHaveBeenCalledTimes(1);
+  });
 });
@@ -81,6 +81,17 @@ const STREAM_THROTTLE_MS = 50;
 // THREAD now (the FSM owns polling->stalled); the window just polls while armed.
 const DEGRADED_POLL_IDLE_MAX_MS = 10 * 60_000;

+// #541: the bound on the persist re-seed (getRun) wait when ENTERING the reconnect
+// ladder after a live SSE drop. The axios client (lib/api-client.ts) sets NO request
+// timeout, and the stalled-idle cap only arms AFTER the FSM enters reconnecting/
+// polling — which never happens if getRun HANGS (connection established, no response).
+// Without this bound a live drop + a hung getRun sticks the FSM in `streaming` with
+// no banner and no poll until the browser socket timeout (minutes) — the silent-freeze
+// class #497 eliminates. This is a deliberate RECOVERY-START bound (drop the live
+// partial + enter the ladder so the poll/idle-cap arms), intentionally much shorter
+// than any network socket timeout — not a network read timeout.
+const RECONNECT_RESEED_TIMEOUT_MS = 4_000;
+
 /** The #487 active (non-terminal) run statuses — mirrors the server's
 *  ACTIVE_RUN_STATUSES. A run-fact is "active" only for these. */
 function isActiveRunStatus(status: string | null | undefined): boolean {
@@ -286,6 +297,9 @@ export default function ChatThread({
  // stalled inactivity cap. Cleared by the cancelReconnect effect / the cap effect.
  const reconnectTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
  const idleCapTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  // #541: the persist re-seed (getRun) timeout race on the disconnect->reconnect
+  // entry. Held in a ref so unmount (DISPOSE cleanup) clears it — no dangling timer.
+  const reseedTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null);

  // #491 tail-only: seed EVERY persisted row unchanged (no strip). The streaming
  // tail holds steps 0..N-1; the run-stream registry's tail (steps >= N) is APPENDED
@@ -748,37 +762,68 @@ export default function ChatThread({
          anchorRef.current = null;
        };
        if (cid) {
-          void getRun(cid)
-            .then((res) => {
-              if (!mountedRef.current) return;
-              const persisted = res.message;
-              if (persisted && persisted.role === "assistant") {
-                anchorRef.current = {
-                  id: persisted.id,
-                  stepsPersisted: stepsPersistedOf(persisted),
-                };
-                // Replace the live partial with the persisted row IN PLACE by id —
-                // the re-seed from persist. The attach's tail (steps >= N) then
-                // appends to a store holding EXACTLY steps 0..N-1: no duplication.
-                setMessages((prev) => mergeById(prev, rowToUiMessage(persisted)));
-              } else {
-                // No persisted assistant row (pre-first-frame break): drop the live
-                // partial + replay from start (no anchor/n) so nothing is duplicated.
-                dropLivePartialAndReplayFromStart();
-              }
-              enterReconnect(res.run?.id ?? runId);
-            })
-            .catch(() => {
-              if (!mountedRef.current) return;
-              // Persist read FAILED: we cannot re-seed from fresh persist, and a
-              // stale mount-time anchor over the live partial would tail-apply
-              // already-present steps -> duplication (a flaky-network blip:
-              // SSE + getRun both fail, network recovers in ~1s, the registry still
-              // covers from the mount frontier). Restore the removed-filter guarantee
-              // instead: drop the live partial + replay from start / 204 -> poll.
+          // #541: bound the persist re-seed wait with a timeout race. getRun goes
+          // through the axios client, which has NO request timeout; a HUNG getRun
+          // (connection open, no response) — distinct from a REJECT, which the
+          // `.catch` already handles — would otherwise never let us enter the ladder,
+          // leaving the FSM stuck in `streaming` with no banner and no poll until the
+          // browser socket timeout. `settled` makes the three branches (resolve /
+          // reject / timeout) mutually exclusive: whichever fires FIRST wins and the
+          // others become no-ops. So a LATE getRun resolve AFTER the timeout is fully
+          // ignored — it cannot (i) re-enter reconnect a second time, (ii) overwrite
+          // the timeout's replay-from-start with a stale re-seed, or (iii) re-arm any
+          // timer. On timeout we take the SAME fallback as the reject path (drop the
+          // live partial + enter the ladder, so the poll and the stalled-idle cap arm).
+          let settled = false;
+          const finishReseed = (apply: () => void): void => {
+            if (settled) return;
+            settled = true;
+            if (reseedTimerRef.current) {
+              clearTimeout(reseedTimerRef.current);
+              reseedTimerRef.current = null;
+            }
+            if (!mountedRef.current) return;
+            apply();
+          };
+          reseedTimerRef.current = setTimeout(() => {
+            finishReseed(() => {
              dropLivePartialAndReplayFromStart();
              enterReconnect(runId);
            });
+          }, RECONNECT_RESEED_TIMEOUT_MS);
+          void getRun(cid)
+            .then((res) => {
+              finishReseed(() => {
+                const persisted = res.message;
+                if (persisted && persisted.role === "assistant") {
+                  anchorRef.current = {
+                    id: persisted.id,
+                    stepsPersisted: stepsPersistedOf(persisted),
+                  };
+                  // Replace the live partial with the persisted row IN PLACE by id —
+                  // the re-seed from persist. The attach's tail (steps >= N) then
+                  // appends to a store holding EXACTLY steps 0..N-1: no duplication.
+                  setMessages((prev) => mergeById(prev, rowToUiMessage(persisted)));
+                } else {
+                  // No persisted assistant row (pre-first-frame break): drop the live
+                  // partial + replay from start (no anchor/n) so nothing is duplicated.
+                  dropLivePartialAndReplayFromStart();
+                }
+                enterReconnect(res.run?.id ?? runId);
+              });
+            })
+            .catch(() => {
+              finishReseed(() => {
+                // Persist read FAILED: we cannot re-seed from fresh persist, and a
+                // stale mount-time anchor over the live partial would tail-apply
+                // already-present steps -> duplication (a flaky-network blip:
+                // SSE + getRun both fail, network recovers in ~1s, the registry still
+                // covers from the mount frontier). Restore the removed-filter guarantee
+                // instead: drop the live partial + replay from start / 204 -> poll.
+                dropLivePartialAndReplayFromStart();
+                enterReconnect(runId);
+              });
+            });
        } else {
          dropLivePartialAndReplayFromStart();
          enterReconnect(runId);
@@ -903,6 +948,12 @@ export default function ChatThread({
    }
    return () => {
      mountedRef.current = false;
+      // #541: clear the in-flight persist re-seed timeout (not an FSM effect timer,
+      // so DISPOSE does not touch it) — no dangling setTimeout after unmount.
+      if (reseedTimerRef.current) {
+        clearTimeout(reseedTimerRef.current);
+        reseedTimerRef.current = null;
+      }
      dispatch({ type: "DISPOSE" }); // aborts attach + timers, bumps epoch (I5)
    };
    // Mount-only by design; the parent remounts per chat via `key`.
@@ -27,6 +27,7 @@ vi.mock("@/features/ai-chat/utils/markdown.ts", async () => {

 import MessageItem from "./message-item";
 import { messageSignature } from "@/features/ai-chat/utils/message-signature.ts";
+import { splitPlainChunks } from "./streaming-plain-text";

 // matchMedia (read by MantineProvider) is stubbed globally in vitest.setup.ts.

@@ -114,3 +115,89 @@ describe("MessageItem markdown memoization", () => {
    expect(queryByText("streamed answer")).not.toBeNull();
  });
 });
+
+// PERF SMOKE (#492): the whole point of the incremental streaming render is that
+// the ANSWER path costs O(number of markdown blocks), NOT O(number of throttled
+// ~20Hz ticks). Pre-#492 the finalized MarkdownPart re-parsed the WHOLE growing
+// answer on every delta — a synthetic ~100 KB stream measured 394 renderChatMarkdown
+// calls (one per tick). With the incremental render each STABILIZED block is parsed
+// exactly once (memoized in MarkdownChunk) and the live tail is cheap plain text, so
+// the call count collapses to ~= the block count regardless of tick granularity.
+describe("MessageItem streaming answer render is O(blocks), not O(ticks)", () => {
+  // ~100 KB answer. Each section is a heading + a paragraph — TWO blank-line
+  // delimited markdown blocks — so the safe-cut block count is ~2× the section
+  // count. The perf claim is about the BLOCK count (the memoization granularity),
+  // measured directly with splitPlainChunks below, not the section count.
+  const buildAnswer = () => {
+    const SECTIONS = 100;
+    const paragraphs: string[] = [];
+    for (let i = 0; i < SECTIONS; i++) {
+      paragraphs.push(`## Section ${i}\n\n` + "lorem ipsum dolor ".repeat(55));
+    }
+    const full = paragraphs.join("\n\n");
+    // The number of memoized markdown blocks the incremental render splits into
+    // (all but the live tail are parsed once each).
+    return { full, blocks: splitPlainChunks(full).length };
+  };
+
+  const streamMsg = (text: string, state: "streaming" | "done"): UIMessage =>
+    ({
+      id: "m1",
+      role: "assistant",
+      parts: [{ type: "text", text, state }],
+    }) as UIMessage;
+
+  it("parses each block ~once over a 100KB stream (≈blocks, ≪ ticks)", () => {
+    renderChatMarkdownSpy.mockClear();
+    const { full, blocks } = buildAnswer();
+    const CHUNK = 128; // a realistic ~20Hz throttled delta size
+    const ticks = Math.ceil(full.length / CHUNK);
+
+    let msg = streamMsg(full.slice(0, CHUNK), "streaming");
+    const { rerender } = render(
+      <MantineProvider>
+        <MessageItem
+          message={msg}
+          signature={messageSignature(msg)}
+          turnStreaming
+        />
+      </MantineProvider>,
+    );
+    for (let end = 2 * CHUNK; end < full.length; end += CHUNK) {
+      msg = streamMsg(full.slice(0, end), "streaming");
+      rerender(
+        <MantineProvider>
+          <MessageItem
+            message={msg}
+            signature={messageSignature(msg)}
+            turnStreaming
+          />
+        </MantineProvider>,
+      );
+    }
+    // Finalize: the streaming→done flip renders the whole answer through ONE
+    // canonical pass (visual parity), so the finished DOM matches the pre-#492
+    // output. This is the single extra parse on top of the per-block ones.
+    const done = streamMsg(full, "done");
+    rerender(
+      <MantineProvider>
+        <MessageItem message={done} signature={messageSignature(done)} />
+      </MantineProvider>,
+    );
+
+    const calls = renderChatMarkdownSpy.mock.calls.length;
+    // Sanity: the stream really had far more ticks than blocks (else the test is
+    // vacuous — the point is that calls scale with blocks, not ticks).
+    expect(ticks).toBeGreaterThan(blocks * 3);
+    // O(blocks): each stabilized block parsed once + the single final whole-text
+    // parse. A small constant absorbs the finalize render and the live-tail block;
+    // the load-bearing claim is the bound below.
+    expect(calls).toBeLessThanOrEqual(blocks + 2);
+    // ≪ ticks — and, non-vacuously, the blocks WERE parsed (not skipped entirely).
+    expect(calls).toBeLessThan(ticks / 3);
+    expect(calls).toBeGreaterThan(blocks / 2);
+    // MUTATION-VERIFY (documented, not run here): dropping the `memo()` wrapper on
+    // MarkdownChunk (so every stable block re-parses each tick) drives `calls`
+    // toward `ticks` (~394), reddening both upper-bound assertions above.
+  });
+});
@@ -0,0 +1,112 @@
+import { describe, expect, it, vi } from "vitest";
+import { render } from "@testing-library/react";
+import { MantineProvider } from "@mantine/core";
+import type { UIMessage } from "@ai-sdk/react";
+
+// Stub react-i18next (the component reads `useTranslation`). Mirrors the other
+// message-item specs.
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (key: string) => key }),
+}));
+
+import MessageItem from "./message-item";
+import { messageSignature } from "@/features/ai-chat/utils/message-signature.ts";
+// The REAL canonical renderer (NOT the spy the memo test installs): this file
+// exercises the actual markdown output so the visual-regression assertions below
+// compare against genuine HTML (incl. the schema's `<li><p>` wrappers).
+import { renderChatMarkdown } from "@/features/ai-chat/utils/markdown.ts";
+import classes from "./ai-chat.module.css";
+
+const msg = (
+  parts: UIMessage["parts"],
+  extra?: Partial<UIMessage>,
+): UIMessage =>
+  ({ id: "m1", role: "assistant", parts, ...extra }) as UIMessage;
+
+const renderRow = (message: UIMessage, turnStreaming = false) =>
+  render(
+    <MantineProvider>
+      <MessageItem
+        message={message}
+        signature={messageSignature(message)}
+        turnStreaming={turnStreaming}
+      />
+    </MantineProvider>,
+  );
+
+// A rich multi-block answer that exercises headings, a list (the `<li><p>` case
+// the scoped CSS tightens), inline emphasis, and multiple paragraphs.
+const ANSWER = [
+  "# Заголовок",
+  "",
+  "Первый абзац с **жирным** и `кодом`.",
+  "",
+  "- пункт один",
+  "- пункт два",
+  "",
+  "Второй абзац.",
+].join("\n");
+
+describe("MessageItem final render — visual parity with the canonical pipeline", () => {
+  it("a finalized text part renders exactly renderChatMarkdown(text)", () => {
+    const { container } = renderRow(
+      msg([{ type: "text", text: ANSWER, state: "done" }]),
+    );
+    const block = container.querySelector(`.${classes.markdown}`);
+    expect(block).not.toBeNull();
+    // Byte-for-byte the canonical output (the SAME whole-text pass the pre-#492
+    // MarkdownPart produced), including `<li><p>…</p></li>` wrappers.
+    expect(block!.innerHTML).toBe(renderChatMarkdown(ANSWER, {}));
+    // The list wrapper is really present (guards against a vacuous empty render).
+    expect(container.querySelectorAll("li p").length).toBe(2);
+  });
+
+  it("the streaming incremental view CONVERGES to the canonical render on finish", () => {
+    // Mount mid-stream (live tail) — the DOM here is the incremental view.
+    const { container, rerender } = render(
+      <MantineProvider>
+        <MessageItem
+          message={msg([{ type: "text", text: ANSWER, state: "streaming" }])}
+          signature={messageSignature(
+            msg([{ type: "text", text: ANSWER, state: "streaming" }]),
+          )}
+          turnStreaming
+        />
+      </MantineProvider>,
+    );
+    // Finish the turn: state flips to done AND the turn is no longer streaming.
+    const done = msg([{ type: "text", text: ANSWER, state: "done" }]);
+    rerender(
+      <MantineProvider>
+        <MessageItem message={done} signature={messageSignature(done)} />
+      </MantineProvider>,
+    );
+    // After finish there is exactly ONE canonical markdown container whose HTML is
+    // the whole-text render — identical to the non-streaming path above.
+    const blocks = container.querySelectorAll(`.${classes.markdown}`);
+    expect(blocks.length).toBe(1);
+    expect(blocks[0].innerHTML).toBe(renderChatMarkdown(ANSWER, {}));
+  });
+
+  it("neutralizeInternalLinks is honored on the finalized render", () => {
+    const linkAnswer = "См. [страницу](/p/abc).";
+    const { container } = render(
+      <MantineProvider>
+        <MessageItem
+          message={msg([{ type: "text", text: linkAnswer, state: "done" }])}
+          signature={messageSignature(
+            msg([{ type: "text", text: linkAnswer, state: "done" }]),
+          )}
+          neutralizeInternalLinks
+        />
+      </MantineProvider>,
+    );
+    const block = container.querySelector(`.${classes.markdown}`);
+    expect(block!.innerHTML).toBe(
+      renderChatMarkdown(linkAnswer, { neutralizeInternalLinks: true }),
+    );
+    // The internal link was made inert (no href) by the neutralization flag.
+    const a = container.querySelector("a");
+    expect(a?.hasAttribute("href")).toBe(false);
+  });
+});
@@ -4,6 +4,7 @@ import { useTranslation } from "react-i18next";
 import type { UIMessage } from "@ai-sdk/react";
 import ToolCallCard from "@/features/ai-chat/components/tool-call-card.tsx";
 import ReasoningBlock from "@/features/ai-chat/components/reasoning-block.tsx";
+import { StreamingMarkdownText } from "@/features/ai-chat/components/streaming-markdown-text.tsx";
 import ChatErrorAlert from "@/features/ai-chat/components/chat-error-alert.tsx";
 import ChatStoppedNotice from "@/features/ai-chat/components/chat-stopped-notice.tsx";
 import { ToolUiPart, isToolPart } from "@/features/ai-chat/utils/tool-parts.tsx";
@@ -86,17 +87,39 @@ interface MessageItemProps {
 * One assistant text part rendered as sanitized markdown. Memoized on its inputs
 * so a finalized text part is NOT re-parsed on every streamed delta: during a
 * turn only the actively-growing tail part changes its `text`, so every earlier
- * part hits the memo and skips the expensive marked + DOMPurify pass. Props are
- * primitives, so React.memo's default shallow compare is exactly right (the
- * `text` string is compared by value).
+ * part hits the memo and skips the expensive canonical parse + DOMPurify pass.
+ * Props are primitives, so React.memo's default shallow compare is exactly right
+ * (the `text` string is compared by value).
+ *
+ * Streaming gate (#492) — mirrors ReasoningBlock:
+ *  - `streaming` (this is the live, actively-growing tail part of an in-flight
+ *    turn): render incrementally via StreamingMarkdownText — the stabilized blocks
+ *    go through the canonical pipeline (each parsed ONCE, memoized) and only the
+ *    live tail is cheap plain text. This makes the per-tick cost O(new blocks),
+ *    not the pre-#492 O(ticks) whole-answer re-parse on every ~20Hz delta.
+ *  - finalized (the common case, and the turn-end flip): render the WHOLE text
+ *    through ONE canonical pass — byte-identical to the pre-#492 output (visual
+ *    parity). The row re-renders on the streaming→done flip because
+ *    `messageSignature` tracks each part's `state` (and `turnStreaming` flips at
+ *    turn end), so the incremental view always converges to this single render.
 */
 const MarkdownPart = memo(function MarkdownPart({
  text,
  neutralizeInternalLinks,
+  streaming,
 }: {
  text: string;
  neutralizeInternalLinks: boolean;
+  streaming: boolean;
 }) {
+  if (streaming) {
+    return (
+      <StreamingMarkdownText
+        text={text}
+        neutralizeInternalLinks={neutralizeInternalLinks}
+      />
+    );
+  }
  const html = renderChatMarkdown(text, { neutralizeInternalLinks });
  if (html) {
    return (
@@ -179,47 +202,10 @@ function MessageItem({
        {resolveAssistantName(assistantName) ?? t("AI agent")}
      </Text>
      {message.parts.map((part, index) => {
-        if (part.type === "reasoning") {
-          // Reasoning ("thinking") -> a collapsible block with its own token
-          // count. Empty/whitespace reasoning with no authoritative count carries
-          // nothing to show, so skip it (avoids an empty 0-token block).
-          const text = (part as { text?: string }).text ?? "";
-          if (!text.trim() && !(reasoningTokens && reasoningTokens > 0))
-            return null;
-          // Absent state (persisted rows) and "done" both mean finalized.
-          // `messageSignature` already includes each part's `state`, so the
-          // streaming→done flip changes the row signature and re-renders this
-          // row — which is what lets ReasoningBlock switch from chunked plain
-          // text to its one-time markdown parse (see reasoning-block.tsx).
-          // ALSO require the turn to be live: a part stranded at
-          // `state:"streaming"` after the turn ended (no `reasoning-end` — see
-          // the `turnStreaming` prop doc) must still finalize and parse.
-          const streaming =
-            turnStreaming && (part as { state?: string }).state === "streaming";
-          return (
-            <ReasoningBlock
-              key={index}
-              text={text}
-              tokens={reasoningTokens}
-              streaming={streaming}
-            />
-          );
-        }
-
-        if (part.type === "text") {
-          // Skip empty/whitespace-only text parts (a streaming message often
-          // starts with an empty text part before the first token arrives); the
-          // typing indicator covers that gap until real content streams in.
-          if (!part.text.trim()) return null;
-          return (
-            <MarkdownPart
-              key={index}
-              text={part.text}
-              neutralizeInternalLinks={neutralizeInternalLinks}
-            />
-          );
-        }
-
+        // Tool parts (`tool-*` / `dynamic-tool`) are template-literal kinds, so
+        // they cannot be a `switch` case; the runtime guard handles them, and the
+        // switch below covers every CLOSED (literal-typed) part kind with a
+        // compile-time exhaustiveness check in its default.
        if (isToolPart(part.type)) {
          return (
            <ToolCallCard
@@ -232,7 +218,76 @@ function MessageItem({
          );
        }

-        return null;
+        switch (part.type) {
+          case "reasoning": {
+            // Reasoning ("thinking") -> a collapsible block with its own token
+            // count. Empty/whitespace reasoning with no authoritative count
+            // carries nothing to show, so skip it (avoids an empty 0-token block).
+            const text = part.text ?? "";
+            if (!text.trim() && !(reasoningTokens && reasoningTokens > 0))
+              return null;
+            // Absent state (persisted rows) and "done" both mean finalized.
+            // `messageSignature` already includes each part's `state`, so the
+            // streaming→done flip changes the row signature and re-renders this
+            // row — which is what lets ReasoningBlock switch from chunked plain
+            // text to its one-time markdown parse (see reasoning-block.tsx).
+            // ALSO require the turn to be live: a part stranded at
+            // `state:"streaming"` after the turn ended (no `reasoning-end` — see
+            // the `turnStreaming` prop doc) must still finalize and parse.
+            const streaming = turnStreaming && part.state === "streaming";
+            return (
+              <ReasoningBlock
+                key={index}
+                text={text}
+                tokens={reasoningTokens}
+                streaming={streaming}
+              />
+            );
+          }
+
+          case "text": {
+            // Skip empty/whitespace-only text parts (a streaming message often
+            // starts with an empty text part before the first token arrives); the
+            // typing indicator covers that gap until real content streams in.
+            if (!part.text.trim()) return null;
+            // The live, actively-growing tail part of the in-flight turn renders
+            // incrementally (see MarkdownPart); a finalized part (persisted, or
+            // the turn-end flip) renders the whole text through one canonical
+            // pass. Same liveness rule as the reasoning branch above.
+            const streaming = turnStreaming && part.state === "streaming";
+            return (
+              <MarkdownPart
+                key={index}
+                text={part.text}
+                neutralizeInternalLinks={neutralizeInternalLinks}
+                streaming={streaming}
+              />
+            );
+          }
+
+          case "source-url":
+          case "source-document":
+          case "file":
+          case "step-start":
+            // Not surfaced in the chat bubble (v1) — same as the pre-#492 default.
+            return null;
+
+          default: {
+            // Compile-time exhaustiveness over the CLOSED union members: every
+            // literal-typed part kind is handled above, so the only kinds that
+            // can reach here are the OPEN template-literal ones (`tool-*` — caught
+            // by the guard at runtime — and `data-*`) plus `dynamic-tool`. Adding
+            // a NEW closed part kind to UIMessagePart makes this assignment fail
+            // to compile, forcing it to be handled instead of silently ignored
+            // (this replaces the pre-#492 fall-through `return null` + WARNING).
+            const _exhaustive:
+              | `tool-${string}`
+              | "dynamic-tool"
+              | `data-${string}` = part.type;
+            void _exhaustive;
+            return null;
+          }
+        }
      })}
      {/* A persisted turn error (server stored it in metadata.error). Rendered
          here so it survives a thread remount and shows in reopened history. */}
@@ -0,0 +1,96 @@
+import { memo, useMemo } from "react";
+import { splitPlainChunks } from "@/features/ai-chat/components/streaming-plain-text.tsx";
+import { renderChatMarkdown } from "@/features/ai-chat/utils/markdown.ts";
+import classes from "@/features/ai-chat/components/ai-chat.module.css";
+
+/**
+ * One STABILIZED markdown block, rendered through the canonical pipeline and
+ * memoized on its string prop. During streaming only the TAIL chunk grows (the
+ * `splitPlainChunks` append-only invariant guarantees every earlier chunk is
+ * byte-identical across deltas), so React skips every stable block and each one
+ * is parsed by `renderChatMarkdown` EXACTLY ONCE — turning the pre-#492
+ * "re-parse the whole accumulated answer on every ~20Hz tick" (O(ticks)) into
+ * O(number of blocks). The markup is DOMPurify-sanitized inside renderChatMarkdown
+ * before it reaches `dangerouslySetInnerHTML`.
+ *
+ * NOTE (transient streaming-only artifact): a safe cut is a blank-line boundary,
+ * so a construct that legitimately contains a blank line (e.g. a fenced code block
+ * with an empty line) can be split across chunks and render oddly WHILE it is still
+ * streaming. This is cosmetic and self-heals: the moment the part finalizes,
+ * MarkdownPart renders the WHOLE text through one canonical pass (visual parity
+ * with the pre-#492 output). The reasoning path makes the same trade (plain text
+ * while streaming, one markdown parse at the end).
+ */
+const MarkdownChunk = memo(function MarkdownChunk({
+  text,
+  neutralizeInternalLinks,
+}: {
+  text: string;
+  neutralizeInternalLinks: boolean;
+}) {
+  const html = renderChatMarkdown(text, { neutralizeInternalLinks });
+  if (html) {
+    return (
+      <div
+        className={classes.markdown}
+        // Sanitized by renderChatMarkdown (DOMPurify) before insertion.
+        dangerouslySetInnerHTML={{ __html: html }}
+      />
+    );
+  }
+  // Malformed/unsupported markdown could not render synchronously: raw text.
+  return (
+    <div className={classes.markdown} style={{ whiteSpace: "pre-wrap" }}>
+      {text}
+    </div>
+  );
+});
+
+/**
+ * The cheap streaming-time stand-in for the finalized answer's one-time markdown
+ * parse (see MarkdownPart in message-item.tsx). Mirrors StreamingPlainText's
+ * chunked-memo pattern but renders the STABILIZED prefix as real markdown (each
+ * block parsed once, memoized) and only the LIVE tail as flat plain text — so the
+ * user sees formatted output for everything up to the last safe cut, and the not-
+ * yet-stable tail (which markdown-parsing every tick would make O(ticks)) stays a
+ * single cheap escaped text node until it stabilizes into a new block.
+ *
+ * `splitPlainChunks` yields chunks where, under append-only growth, every chunk
+ * except the LAST is immutable; the last chunk is the live tail. Index keys are
+ * therefore stable (a given index never changes to a different chunk's content).
+ */
+export function StreamingMarkdownText({
+  text,
+  neutralizeInternalLinks,
+}: {
+  text: string;
+  neutralizeInternalLinks: boolean;
+}) {
+  const chunks = useMemo(() => splitPlainChunks(text), [text]);
+  return (
+    <>
+      {chunks.map((chunk, index) =>
+        index < chunks.length - 1 ? (
+          <MarkdownChunk
+            key={index}
+            text={chunk}
+            neutralizeInternalLinks={neutralizeInternalLinks}
+          />
+        ) : (
+          // The live tail: flat, React-escaped plain text (no markdown parse, no
+          // sanitizer, no innerHTML). `pre-wrap` preserves its newlines; trailing
+          // separator newlines are dropped at display time so the block gap comes
+          // from the markdown margins, not a doubled empty line (mirrors
+          // PlainChunk in streaming-plain-text.tsx).
+          <div
+            key={index}
+            className={classes.markdown}
+            style={{ whiteSpace: "pre-wrap" }}
+          >
+            {chunk.replace(/\n+$/, "")}
+          </div>
+        ),
+      )}
+    </>
+  );
+}
@@ -27,11 +27,15 @@ vi.mock("@/features/space/queries/space-query.ts", () => ({
 import {
  buildChildrenByParent,
  CommentEditorWithActions,
+  sortResolvedByResolvedAt,
 } from "./comment-list-with-tabs";

 const c = (id: string, parentCommentId: string | null = null): IComment =>
  ({ id, parentCommentId }) as IComment;

+const resolvedAtComment = (id: string, resolvedAt: unknown): IComment =>
+  ({ id, resolvedAt }) as unknown as IComment;
+
 describe("buildChildrenByParent (childrenByParent grouping)", () => {
  it("returns an empty map for undefined or empty input", () => {
    expect(buildChildrenByParent(undefined).size).toBe(0);
@@ -71,6 +75,48 @@ describe("buildChildrenByParent (childrenByParent grouping)", () => {
  });
 });

+describe("sortResolvedByResolvedAt (Resolved tab order, #542)", () => {
+  it("orders by resolvedAt DESC — newest resolve first — with ISO-STRING values", () => {
+    // At runtime resolvedAt is an ISO string (axios JSON / WS subscription), so
+    // the sort must coerce with new Date(...) before .getTime().
+    const older = resolvedAtComment("older", "2026-07-10T10:00:00.000Z");
+    const newest = resolvedAtComment("newest", "2026-07-12T10:00:00.000Z");
+    const middle = resolvedAtComment("middle", "2026-07-11T10:00:00.000Z");
+
+    const out = sortResolvedByResolvedAt([older, newest, middle]);
+    expect(out.map((x) => x.id)).toEqual(["newest", "middle", "older"]);
+  });
+
+  it("also handles Date instances (optimistic onMutate window)", () => {
+    const older = resolvedAtComment("older", new Date("2026-01-01T00:00:00Z"));
+    const newer = resolvedAtComment("newer", new Date("2026-06-01T00:00:00Z"));
+    expect(sortResolvedByResolvedAt([older, newer]).map((x) => x.id)).toEqual([
+      "newer",
+      "older",
+    ]);
+  });
+
+  it("does not mutate the input array", () => {
+    const a = resolvedAtComment("a", "2026-01-01T00:00:00.000Z");
+    const b = resolvedAtComment("b", "2026-02-01T00:00:00.000Z");
+    const input = [a, b];
+    sortResolvedByResolvedAt(input);
+    expect(input.map((x) => x.id)).toEqual(["a", "b"]);
+  });
+
+  it("keeps stable order for equal resolvedAt timestamps", () => {
+    const ts = "2026-03-03T03:03:03.000Z";
+    const x = resolvedAtComment("x", ts);
+    const y = resolvedAtComment("y", ts);
+    const z = resolvedAtComment("z", ts);
+    expect(sortResolvedByResolvedAt([x, y, z]).map((c) => c.id)).toEqual([
+      "x",
+      "y",
+      "z",
+    ]);
+  });
+});
+
 function renderReplyEditor() {
  return render(
    <MantineProvider>
@@ -53,6 +53,22 @@ export function buildChildrenByParent(
  return m;
 }

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

-    return { activeComments: active, resolvedComments: resolved };
+    return {
+      activeComments: active,
+      resolvedComments: sortResolvedByResolvedAt(resolved),
+    };
  }, [comments]);

  // Index replies by their parent once, instead of an O(n^2) filter per thread.
@@ -0,0 +1,353 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import React from "react";
+import { renderHook, waitFor } from "@testing-library/react";
+import {
+  QueryClient,
+  QueryClientProvider,
+  InfiniteData,
+} from "@tanstack/react-query";
+
+/**
+ * Coverage for the resolve/reopen mutation (#542): the Undo-in-toast reopen and
+ * its double-click guard, the terminal 404 branch (drop from cache + clear the
+ * inline mark, no rollback), and the directional error copy.
+ */
+
+// A fake TipTap editor injected via the mocked pageEditorAtom, so we can assert
+// the mutation clears the inline comment mark (unsetComment / setCommentResolved).
+const editorMock = vi.hoisted(() => ({
+  current: {
+    isDestroyed: false,
+    commands: { unsetComment: vi.fn(), setCommentResolved: vi.fn() },
+  } as {
+    isDestroyed: boolean;
+    commands: {
+      unsetComment: (id: string) => void;
+      setCommentResolved: (id: string, v: boolean) => void;
+    };
+  } | null,
+}));
+
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: vi.fn(), hide: vi.fn() },
+}));
+
+vi.mock("jotai", () => ({
+  atom: (v: unknown) => v,
+  useAtomValue: () => editorMock.current,
+}));
+
+vi.mock("@/features/comment/services/comment-service", () => ({
+  applySuggestion: vi.fn(),
+  dismissSuggestion: vi.fn(),
+  createComment: vi.fn(),
+  updateComment: vi.fn(),
+  deleteComment: vi.fn(),
+  resolveComment: vi.fn(),
+  getPageComments: vi.fn(),
+}));
+
+import { notifications } from "@mantine/notifications";
+import { resolveComment } from "@/features/comment/services/comment-service";
+import {
+  useResolveCommentMutation,
+  RESOLVE_UNDO_AUTOCLOSE_MS,
+  RQ_KEY,
+} from "@/features/comment/queries/comment-query";
+import { IComment } from "@/features/comment/types/comment.types";
+
+const PAGE_ID = "page-1";
+
+function seededClient(comment: IComment) {
+  const queryClient = new QueryClient({
+    defaultOptions: { mutations: { retry: false } },
+  });
+  const seed: InfiniteData<any> = {
+    pageParams: [undefined],
+    pages: [
+      { items: [comment], meta: { hasNextPage: false, nextCursor: null } },
+    ],
+  };
+  queryClient.setQueryData(RQ_KEY(PAGE_ID), seed);
+  const wrapper = ({ children }: { children: React.ReactNode }) => (
+    <QueryClientProvider client={queryClient}>{children}</QueryClientProvider>
+  );
+  return { queryClient, wrapper };
+}
+
+function items(queryClient: QueryClient): IComment[] {
+  const cache = queryClient.getQueryData(RQ_KEY(PAGE_ID)) as
+    | InfiniteData<any>
+    | undefined;
+  return cache?.pages.flatMap((p) => p.items) ?? [];
+}
+
+const comment = (over?: Partial<IComment>): IComment =>
+  ({
+    id: "c-1",
+    pageId: PAGE_ID,
+    content: "{}",
+    creatorId: "u-1",
+    workspaceId: "ws-1",
+    createdAt: new Date(),
+    resolvedAt: null,
+    ...over,
+  }) as IComment;
+
+// Pull the inline Undo button's onClick out of the success toast's message tree.
+function undoOnClickFromToast(): () => void {
+  const call = vi
+    .mocked(notifications.show)
+    .mock.calls.map((c) => c[0])
+    .find((arg: any) => arg?.autoClose === RESOLVE_UNDO_AUTOCLOSE_MS);
+  expect(call).toBeTruthy();
+  const message: any = (call as any).message;
+  // message = Group( Text, Button ); grab the Button element's onClick.
+  const children = message.props.children as any[];
+  const button = children[1];
+  return button.props.onClick;
+}
+
+describe("useResolveCommentMutation — Undo toast (#542)", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    editorMock.current = {
+      isDestroyed: false,
+      commands: { unsetComment: vi.fn(), setCommentResolved: vi.fn() },
+    };
+  });
+
+  it("resolve shows an Undo toast with autoClose=10000ms; reopen shows NO Undo", async () => {
+    vi.mocked(resolveComment).mockImplementation(async (data) =>
+      comment({
+        resolvedAt: data.resolved ? (new Date() as any) : null,
+      }),
+    );
+    const { wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: true,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    const resolveToast = vi
+      .mocked(notifications.show)
+      .mock.calls.map((c) => c[0])
+      .find((a: any) => a?.autoClose === RESOLVE_UNDO_AUTOCLOSE_MS);
+    expect(resolveToast).toBeTruthy();
+    expect((resolveToast as any).id).toBe("resolve-undo-c-1");
+    expect((resolveToast as any).autoClose).toBe(10000);
+
+    // Now a reopen → plain toast, no autoClose/Undo, no id.
+    vi.clearAllMocks();
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: false,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+    const calls = vi.mocked(notifications.show).mock.calls.map((c) => c[0]);
+    expect(
+      calls.some((a: any) => a?.autoClose === RESOLVE_UNDO_AUTOCLOSE_MS),
+    ).toBe(false);
+    expect(calls).toContainEqual({ message: "Comment re-opened successfully" });
+  });
+
+  it("double/fast Undo click fires reopen EXACTLY once (guard)", async () => {
+    vi.mocked(resolveComment).mockImplementation(async (data) =>
+      comment({ resolvedAt: data.resolved ? (new Date() as any) : null }),
+    );
+    const { wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: true,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    const onClick = undoOnClickFromToast();
+    // Fire twice synchronously (notifications.hide is not synchronous).
+    onClick();
+    onClick();
+
+    await waitFor(() => {
+      const reopenCalls = vi
+        .mocked(resolveComment)
+        .mock.calls.filter(([d]) => d.resolved === false);
+      expect(reopenCalls).toHaveLength(1);
+    });
+    // The mark was cleared once via setCommentResolved(id, false).
+    expect(editorMock.current!.commands.setCommentResolved).toHaveBeenCalledWith(
+      "c-1",
+      false,
+    );
+    // The toast was hidden.
+    expect(notifications.hide).toHaveBeenCalledWith("resolve-undo-c-1");
+  });
+
+  it("404 → drops the comment from cache, clears the inline mark, no rollback, no Undo", async () => {
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 404 } });
+    const { queryClient, wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current
+      .mutateAsync({ commentId: "c-1", pageId: PAGE_ID, resolved: true })
+      .catch(() => undefined);
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    // Removed from cache (NOT rolled back to a phantom).
+    expect(items(queryClient)).toHaveLength(0);
+    // Inline mark cleared via unsetComment (mandatory — no panel row left to do it).
+    expect(editorMock.current!.commands.unsetComment).toHaveBeenCalledWith(
+      "c-1",
+    );
+    // Neutral message, red, and crucially NOT the success copy and NO Undo toast.
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Comment no longer exists",
+      color: "red",
+    });
+    const calls = vi.mocked(notifications.show).mock.calls.map((c) => c[0]);
+    expect(
+      calls.some((a: any) => a?.autoClose === RESOLVE_UNDO_AUTOCLOSE_MS),
+    ).toBe(false);
+  });
+
+  it("404 does not crash when the editor is gone (read-only / panel closed)", async () => {
+    editorMock.current = null;
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 404 } });
+    const { queryClient, wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current
+      .mutateAsync({ commentId: "c-1", pageId: PAGE_ID, resolved: true })
+      .catch(() => undefined);
+    await waitFor(() => expect(result.current.isError).toBe(true));
+    expect(items(queryClient)).toHaveLength(0);
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Comment no longer exists",
+      color: "red",
+    });
+  });
+
+  it("non-404 error on REOPEN shows 'Failed to re-open comment' and rolls back", async () => {
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 500 } });
+    // Seed a RESOLVED comment (the reopen target).
+    const resolved = comment({ resolvedAt: new Date() as any });
+    const { queryClient, wrapper } = seededClient(resolved);
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current
+      .mutateAsync({ commentId: "c-1", pageId: PAGE_ID, resolved: false })
+      .catch(() => undefined);
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Failed to re-open comment",
+      color: "red",
+    });
+    expect(notifications.show).not.toHaveBeenCalledWith(
+      expect.objectContaining({ message: "Failed to resolve comment" }),
+    );
+    // Rolled back: the comment is still present and still resolved.
+    expect(items(queryClient)).toHaveLength(1);
+    expect(items(queryClient)[0].resolvedAt).toBeTruthy();
+  });
+
+  it("reopen via Undo FAILS (non-404) → inline mark is NOT left cleared (doc↔panel stay consistent)", async () => {
+    // First resolve succeeds → produces the Undo toast (no mark change on resolve).
+    vi.mocked(resolveComment).mockResolvedValueOnce(
+      comment({ resolvedAt: new Date() as any }),
+    );
+    const { queryClient, wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: true,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    // Now the reopen fired by Undo fails with a 500.
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 500 } });
+    const onClick = undoOnClickFromToast();
+    onClick();
+
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    // Core F1 guarantee: the mark-clear now lives in the reopen onSuccess, so a
+    // FAILED reopen must never flip the inline mark to unresolved — otherwise the
+    // doc would show an active highlight the panel still treats as resolved and
+    // the collab mark would diverge with nothing committed on the server.
+    expect(
+      editorMock.current!.commands.setCommentResolved,
+    ).not.toHaveBeenCalledWith("c-1", false);
+    // Cache rolled back: the comment stays resolved and present.
+    expect(items(queryClient)).toHaveLength(1);
+    expect(items(queryClient)[0].resolvedAt).toBeTruthy();
+  });
+
+  it("reopen success with a null editorRef degrades gracefully (no throw, no-op)", async () => {
+    // Read-only view / panel closed: pageEditorAtom is null on the success path.
+    editorMock.current = null;
+    vi.mocked(resolveComment).mockResolvedValue(comment({ resolvedAt: null }));
+    const resolved = comment({ resolvedAt: new Date() as any });
+    const { queryClient, wrapper } = seededClient(resolved);
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current.mutateAsync({
+      commentId: "c-1",
+      pageId: PAGE_ID,
+      resolved: false,
+    });
+    await waitFor(() => expect(result.current.isSuccess).toBe(true));
+
+    // No crash from the reopen mark-clear; the plain reopen toast is still shown.
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Comment re-opened successfully",
+    });
+    // Cache updated to reopened (resolvedAt cleared by the server payload).
+    expect(items(queryClient)).toHaveLength(1);
+    expect(items(queryClient)[0].resolvedAt).toBeFalsy();
+  });
+
+  it("non-404 error on RESOLVE shows 'Failed to resolve comment' and rolls back", async () => {
+    vi.mocked(resolveComment).mockRejectedValue({ response: { status: 500 } });
+    const { queryClient, wrapper } = seededClient(comment());
+    const { result } = renderHook(() => useResolveCommentMutation(), {
+      wrapper,
+    });
+
+    await result.current
+      .mutateAsync({ commentId: "c-1", pageId: PAGE_ID, resolved: true })
+      .catch(() => undefined);
+    await waitFor(() => expect(result.current.isError).toBe(true));
+
+    expect(notifications.show).toHaveBeenCalledWith({
+      message: "Failed to resolve comment",
+      color: "red",
+    });
+    // Rolled back to open (previousCache), still present.
+    expect(items(queryClient)).toHaveLength(1);
+    expect(items(queryClient)[0].resolvedAt).toBeFalsy();
+  });
+});
@@ -20,12 +20,19 @@ import {
  ISuggestionOutcome,
 } from "@/features/comment/types/comment.types";
 import { notifications } from "@mantine/notifications";
+import { Button, Group, Text } from "@mantine/core";
 import { IPagination } from "@/lib/types.ts";
 import { useTranslation } from "react-i18next";
-import { useEffect, useMemo } from "react";
+import React, { useEffect, useMemo, useRef } from "react";
+import { useAtomValue } from "jotai";
+import { pageEditorAtom } from "@/features/editor/atoms/editor-atoms";

 export const RQ_KEY = (pageId: string) => ["comments", pageId];

+// How long the resolve success toast (with its inline Undo) stays up before it
+// auto-closes. Policy constant — no env override.
+export const RESOLVE_UNDO_AUTOCLOSE_MS = 10000;
+
 export function useCommentsQuery(params: ICommentParams) {
  const query = useInfiniteQuery({
    queryKey: RQ_KEY(params.pageId),
@@ -376,7 +383,25 @@ export function useResolveCommentMutation() {
  const queryClient = useQueryClient();
  const { t } = useTranslation();

-  return useMutation({
+  // Keep the live editor in a ref: the toast's Undo (and the 404 branch) must
+  // clear the inline comment mark AFTER the originating CommentListItem has
+  // unmounted (resolving pulls the comment out of the Open list, so its item is
+  // already gone by the time the 10s toast is clicked). In read-only view
+  // pageEditorAtom is null and the mark converges via the server's
+  // COMMENT_MARK_UPDATE job instead.
+  const editor = useAtomValue(pageEditorAtom);
+  const editorRef = useRef(editor);
+  editorRef.current = editor;
+
+  // Self-reference the mutation so the toast's Undo can re-invoke it (reopen)
+  // long after the triggering component unmounted. Declared BEFORE useMutation
+  // and assigned AFTER; the onClick reads mutationRef.current at CALL time, not
+  // definition time, so there is no initialization cycle.
+  const mutationRef = useRef<{
+    mutate: (vars: IResolveComment) => void;
+  } | null>(null);
+
+  const mutation = useMutation({
    mutationFn: (data: IResolveComment) => resolveComment(data),
    onMutate: async (variables) => {
      await queryClient.cancelQueries({ queryKey: RQ_KEY(variables.pageId) });
@@ -401,7 +426,39 @@ export function useResolveCommentMutation() {

      return { previousCache };
    },
-    onError: (_err, variables, context) => {
+    onError: (err: any, variables, context) => {
+      // Terminal 404: the comment was really deleted (missing comment or deleted
+      // page — access denial is 403, resolve is idempotent so no 400). Do NOT
+      // roll back (that would resurrect a phantom row in Resolved); instead drop
+      // it from the cache and clear its now-orphaned inline mark. Mirrors
+      // handleDeleteComment and the dismiss-mutation 404 branch.
+      if (err?.response?.status === 404) {
+        const cache = queryClient.getQueryData(RQ_KEY(variables.pageId)) as
+          | InfiniteData<IPagination<IComment>>
+          | undefined;
+        if (cache) {
+          queryClient.setQueryData(
+            RQ_KEY(variables.pageId),
+            removeCommentFromCache(cache, variables.commentId),
+          );
+        }
+        const ed = editorRef.current;
+        if (ed && !ed.isDestroyed) {
+          try {
+            ed.commands.unsetComment(variables.commentId);
+          } catch {
+            /* editor gone / mark already removed */
+          }
+        }
+        notifications.show({
+          message: t("Comment no longer exists"),
+          color: "red",
+        });
+        return;
+      }
+
+      // Generic failure: roll back the optimistic update and show a DIRECTIONAL
+      // error (resolve vs. reopen), not always "resolve".
      if (context?.previousCache) {
        queryClient.setQueryData(
          RQ_KEY(variables.pageId),
@@ -409,7 +466,9 @@ export function useResolveCommentMutation() {
        );
      }
      notifications.show({
-        message: t("Failed to resolve comment"),
+        message: variables.resolved
+          ? t("Failed to resolve comment")
+          : t("Failed to re-open comment"),
        color: "red",
      });
    },
@@ -430,11 +489,72 @@ export function useResolveCommentMutation() {
        );
      }

+      // Reopen keeps the plain toast without an Undo.
+      if (!variables.resolved) {
+        // Clear the inline mark ONLY after the server confirms the reopen, so a
+        // failed reopen never leaves an active highlight the panel still treats
+        // as resolved. Mirrors the 404 branch's editor-liveness guard/try-catch.
+        // The button-triggered reopen already set the mark, so this is an
+        // idempotent no-op there.
+        const ed = editorRef.current;
+        if (ed && !ed.isDestroyed) {
+          try {
+            ed.commands.setCommentResolved(variables.commentId, false);
+          } catch {
+            /* editor gone — server COMMENT_MARK_UPDATE converges it */
+          }
+        }
+        notifications.show({ message: t("Comment re-opened successfully") });
+        return;
+      }
+
+      // Resolve: attach an inline Undo (reopen) to the success toast. Built with
+      // React.createElement because this is a .ts module (no JSX).
+      const { commentId, pageId } = variables;
+      const notificationId = `resolve-undo-${commentId}`;
+      // Double-click guard: notifications.hide is NOT synchronous, so the button
+      // stays clickable for a frame or two — without this a fast double-click
+      // would fire reopen twice.
+      let done = false;
      notifications.show({
-        message: variables.resolved
-          ? t("Comment resolved successfully")
-          : t("Comment re-opened successfully"),
+        id: notificationId,
+        autoClose: RESOLVE_UNDO_AUTOCLOSE_MS,
+        message: React.createElement(
+          Group,
+          { justify: "space-between", wrap: "nowrap", gap: "md" },
+          React.createElement(
+            Text,
+            { size: "sm" },
+            t("Comment resolved successfully"),
+          ),
+          React.createElement(
+            Button,
+            {
+              variant: "subtle",
+              size: "compact-sm",
+              onClick: () => {
+                if (done) return;
+                done = true;
+                // Reopen via the SAME mutation (read at click time — the
+                // originating item is already unmounted).
+                mutationRef.current?.mutate({
+                  commentId,
+                  pageId,
+                  resolved: false,
+                });
+                // The inline mark is cleared in the reopen mutation's onSuccess
+                // (bound to server confirmation), NOT here — clearing it eagerly
+                // would desync the doc from the panel if reopen then fails.
+                notifications.hide(notificationId);
+              },
+            },
+            t("Undo"),
+          ),
+        ),
      });
    },
  });
+
+  mutationRef.current = mutation;
+  return mutation;
 }
@@ -0,0 +1,45 @@
+import { describe, it, expect } from "vitest";
+import {
+  formatHeadline,
+  formatDayTotal,
+  formatGapMinutes,
+} from "./format-work-time";
+
+const MIN = 60 * 1000;
+// Fake translator: renders the key with {{tokens}} substituted, so the tests
+// assert the rounding + branch selection without depending on the i18n catalogue.
+const t = (key: string, opts?: Record<string, unknown>) =>
+  key.replace(/\{\{(\w+)\}\}/g, (_, k) => String(opts?.[k] ?? ""));
+
+describe("formatHeadline", () => {
+  it("prefixes ≈ and rounds to a 5-minute step", () => {
+    expect(formatHeadline(4 * 60 * MIN + 27 * MIN, t)).toBe("≈ 4h 25m");
+    expect(formatHeadline(90 * MIN, t)).toBe("≈ 1h 30m");
+  });
+
+  it("shows hours only / minutes only cleanly", () => {
+    expect(formatHeadline(120 * MIN, t)).toBe("≈ 2h");
+    expect(formatHeadline(35 * MIN, t)).toBe("≈ 35m");
+  });
+
+  it("floors a tiny non-zero estimate to 5m, never 0", () => {
+    expect(formatHeadline(2 * MIN, t)).toBe("≈ 5m");
+  });
+
+  it("empty string for zero (widget hidden)", () => {
+    expect(formatHeadline(0, t)).toBe("");
+  });
+});
+
+describe("formatDayTotal", () => {
+  it('renders "h m" and shows — for empty days', () => {
+    expect(formatDayTotal(3 * 60 * MIN + 17 * MIN, t)).toBe("3h 17m");
+    expect(formatDayTotal(0, t)).toBe("—");
+  });
+});
+
+describe("formatGapMinutes", () => {
+  it("converts the tGap ms threshold to whole minutes", () => {
+    expect(formatGapMinutes(15 * MIN)).toBe(15);
+  });
+});
@@ -0,0 +1,45 @@
+// #395 — display formatting for the work-time estimate. Pure functions that take
+// a translator so ru-RU / en-US wording lives in the i18n catalogue and the
+// rounding logic stays unit-testable.
+
+type Translate = (key: string, opts?: Record<string, unknown>) => string;
+
+const MIN = 60 * 1000;
+
+function hm(totalMinutes: number): { hours: number; minutes: number } {
+  return {
+    hours: Math.floor(totalMinutes / 60),
+    minutes: totalMinutes % 60,
+  };
+}
+
+/**
+ * Headline number (§6.1): an ESTIMATE, so rounded to a coarse 5-minute step and
+ * prefixed with "≈". A non-zero-but-tiny estimate floors to 5m rather than
+ * rounding down to "0" (which would read as "no work"). Zero → empty string
+ * (the caller hides the widget).
+ */
+export function formatHeadline(workMs: number, t: Translate): string {
+  if (workMs <= 0) return "";
+  let minutes = Math.round(workMs / MIN / 5) * 5;
+  if (minutes === 0) minutes = 5;
+  const { hours, minutes: m } = hm(minutes);
+  if (hours > 0 && m > 0) return t("≈ {{hours}}h {{minutes}}m", { hours, minutes: m });
+  if (hours > 0) return t("≈ {{hours}}h", { hours });
+  return t("≈ {{minutes}}m", { minutes: m });
+}
+
+/** Per-day sum (§6.2), rounded to the minute. Zero → "—". */
+export function formatDayTotal(activeMs: number, t: Translate): string {
+  if (activeMs <= 0) return "—";
+  const minutes = Math.max(1, Math.round(activeMs / MIN));
+  const { hours, minutes: m } = hm(minutes);
+  if (hours > 0 && m > 0) return t("{{hours}}h {{minutes}}m", { hours, minutes: m });
+  if (hours > 0) return t("{{hours}}h", { hours });
+  return t("{{minutes}}m", { minutes: m });
+}
+
+/** The inactivity threshold, for the "estimate · gap = N min" caption. */
+export function formatGapMinutes(tGapMs: number): number {
+  return Math.round(tGapMs / MIN);
+}
@@ -0,0 +1,25 @@
+import { useQuery, UseQueryResult } from "@tanstack/react-query";
+import { IPageWorkTime } from "./work-time.types";
+import { getPageWorkTime, viewerTimezone } from "./work-time-service";
+
+const WORK_TIME_STALE_TIME = 5 * 60 * 1000;
+
+/**
+ * #395 — the "time worked on this article" estimate + per-day punch-card
+ * buckets. The buckets are computed server-side in the viewer's timezone (so a
+ * midnight-crossing session lands on the right calendar day for the reader).
+ * `enabled` is opt-in so the (cheap but non-trivial) projection query only fires
+ * when the number is actually shown.
+ */
+export function usePageWorkTime(
+  pageId: string,
+  enabled = true,
+): UseQueryResult<IPageWorkTime, Error> {
+  const tz = viewerTimezone();
+  return useQuery({
+    queryKey: ["page-work-time", pageId, tz],
+    queryFn: () => getPageWorkTime(pageId, tz),
+    enabled: enabled && !!pageId,
+    staleTime: WORK_TIME_STALE_TIME,
+  });
+}
@@ -0,0 +1,171 @@
+import { Group, Stack, Text } from "@mantine/core";
+import { useTranslation } from "react-i18next";
+import { useMemo } from "react";
+import { IPageWorkTime, IPerDay, IDayWindow } from "./work-time.types";
+import {
+  formatDayTotal,
+  formatGapMinutes,
+  formatHeadline,
+} from "./format-work-time";
+import classes from "./work-time.module.css";
+
+const DAY_MS = 24 * 60 * 60 * 1000;
+// Collapse a run of this many (or more) consecutive edit-free days into a single
+// "× N days" separator (§6.2 long-range) — the row is still always one day.
+const EMPTY_RUN_COLLAPSE = 8;
+
+type Row =
+  | { type: "day"; day: IPerDay }
+  | { type: "gap"; count: number };
+
+function collapseEmptyRuns(perDay: IPerDay[]): Row[] {
+  const rows: Row[] = [];
+  let emptyRun: IPerDay[] = [];
+  const flush = () => {
+    if (emptyRun.length >= EMPTY_RUN_COLLAPSE) {
+      rows.push({ type: "gap", count: emptyRun.length });
+    } else {
+      for (const d of emptyRun) rows.push({ type: "day", day: d });
+    }
+    emptyRun = [];
+  };
+  for (const d of perDay) {
+    if (d.activeMs === 0 && d.agentMs === 0) {
+      emptyRun.push(d);
+    } else {
+      flush();
+      rows.push({ type: "day", day: d });
+    }
+  }
+  flush();
+  return rows;
+}
+
+function dayHeading(day: number): string {
+  return new Date(day).toLocaleDateString(undefined, {
+    weekday: "short",
+    day: "numeric",
+    month: "short",
+  });
+}
+
+function DayTrack({
+  day,
+  pSingle,
+}: {
+  day: IPerDay;
+  pSingle: number;
+}) {
+  const { t } = useTranslation();
+  const ticks = [6, 12, 18];
+  return (
+    <div className={classes.row}>
+      <span className={classes.dayLabel}>{dayHeading(day.day)}</span>
+      <div className={classes.track}>
+        {ticks.map((h) => (
+          <div
+            key={h}
+            className={classes.hourTick}
+            style={{ left: `${(h / 24) * 100}%` }}
+          />
+        ))}
+        {day.windows.map((w: IDayWindow, i) => {
+          const leftPct = ((w.start - day.day) / DAY_MS) * 100;
+          const widthPct = ((w.end - w.start) / DAY_MS) * 100;
+          const isSingle = w.end - w.start <= pSingle;
+          const cls = [
+            classes.window,
+            w.class === "work" ? classes.windowWork : classes.windowAgent,
+            isSingle ? classes.windowSingle : "",
+          ].join(" ");
+          return (
+            <div
+              key={i}
+              className={cls}
+              style={{
+                left: `${Math.max(0, Math.min(100, leftPct))}%`,
+                width: `${Math.max(0, Math.min(100, widthPct))}%`,
+              }}
+            />
+          );
+        })}
+      </div>
+      <span className={classes.daySum}>
+        {formatDayTotal(day.activeMs, t)}
+      </span>
+    </div>
+  );
+}
+
+interface Props {
+  data: IPageWorkTime;
+}
+
+export default function WorkTimePunchCard({ data }: Props) {
+  const { t } = useTranslation();
+  const rows = useMemo(() => collapseEmptyRuns(data.perDay), [data.perDay]);
+  const gapMin = formatGapMinutes(data.config.tGap);
+
+  if (data.workMs <= 0 && data.agentOnlyMs <= 0) {
+    return (
+      <Text size="sm" c="dimmed" py="md">
+        {t("No editing activity recorded yet.")}
+      </Text>
+    );
+  }
+
+  return (
+    <Stack gap="xs">
+      <Group gap="lg">
+        <Text size="sm" fw={500}>
+          {formatHeadline(data.workMs, t)}
+        </Text>
+        {data.agentOnlyMs > 0 && (
+          <Text size="xs" c="dimmed">
+            {t("agent: {{value}}", { value: formatHeadline(data.agentOnlyMs, t) })}
+          </Text>
+        )}
+      </Group>
+
+      <Group gap="md">
+        <Text size="xs" c="dimmed">
+          <span
+            className={`${classes.legendSwatch} ${classes.windowWork}`}
+            style={{ marginRight: 4 }}
+          />
+          {t("Work")}
+        </Text>
+        <Text size="xs" c="dimmed">
+          <span
+            className={`${classes.legendSwatch} ${classes.windowAgent}`}
+            style={{ marginRight: 4 }}
+          />
+          {t("Agent")}
+        </Text>
+      </Group>
+
+      <div>
+        {rows.map((row, i) =>
+          row.type === "day" ? (
+            <DayTrack
+              key={row.day.dayISO}
+              day={row.day}
+              pSingle={data.config.pSingle}
+            />
+          ) : (
+            <div key={`gap-${i}`} className={classes.gapRow}>
+              {t("× {{count}} days without edits", { count: row.count })}
+            </div>
+          ),
+        )}
+      </div>
+
+      <Text size="xs" c="dimmed" mt="xs">
+        {t("Estimate · timezone {{tz}} · inactivity gap {{gap}} min", {
+          tz: data.tz,
+          gap: gapMin,
+        })}
+      </Text>
+    </Stack>
+  );
+}
@@ -0,0 +1,23 @@
+import api from "@/lib/api-client";
+import { IPageWorkTime } from "./work-time.types";
+
+/** The viewer's IANA timezone (browser locale) — the punch-card lays days out
+ *  in "my evenings", per §6.3/§10. Falls back to UTC if the runtime hides it. */
+export function viewerTimezone(): string {
+  try {
+    return Intl.DateTimeFormat().resolvedOptions().timeZone || "UTC";
+  } catch {
+    return "UTC";
+  }
+}
+
+export async function getPageWorkTime(
+  pageId: string,
+  tz: string,
+): Promise<IPageWorkTime> {
+  const req = await api.post<IPageWorkTime>("/pages/history/time", {
+    pageId,
+    tz,
+  });
+  return req.data;
+}
@@ -0,0 +1,69 @@
+import { Modal, Text, Tooltip, UnstyledButton } from "@mantine/core";
+import { useDisclosure } from "@mantine/hooks";
+import { IconClockHour4 } from "@tabler/icons-react";
+import { useTranslation } from "react-i18next";
+import { usePageWorkTime } from "./use-page-work-time";
+import { formatGapMinutes, formatHeadline } from "./format-work-time";
+import WorkTimePunchCard from "./work-time-punch-card";
+
+interface Props {
+  pageId: string;
+}
+
+/**
+ * #395 — the clickable "time worked on this article" headline (§6.1). Renders
+ * the `work` estimate with a "≈" sign and the inactivity threshold in a tooltip
+ * (it is an estimate, not a stopwatch). Clicking opens the daily punch-card
+ * (§6.2). Renders nothing until there is a non-zero human OR agent estimate, so a
+ * brand-new / never-edited page shows no widget. For an agent-only-edited page
+ * (workMs===0, agentOnlyMs>0) the headline shows the agent estimate (labelled
+ * `agent:`, matching the punch-card) so the punch-card stays reachable (#395:
+ * "how much a HUMAN and separately the AGENT").
+ */
+export default function WorkTimeStat({ pageId }: Props) {
+  const { t } = useTranslation();
+  const [opened, { open, close }] = useDisclosure(false);
+  const { data } = usePageWorkTime(pageId);
+
+  if (!data || (data.workMs <= 0 && data.agentOnlyMs <= 0)) return null;
+
+  const agentOnly = data.workMs <= 0;
+  const label = agentOnly
+    ? t("agent: {{value}}", { value: formatHeadline(data.agentOnlyMs, t) })
+    : formatHeadline(data.workMs, t);
+  const gapMin = formatGapMinutes(data.config.tGap);
+
+  return (
+    <>
+      <Tooltip
+        label={t("Estimated time worked (inactivity gap {{gap}} min)", {
+          gap: gapMin,
+        })}
+        position="bottom"
+      >
+        <UnstyledButton
+          onClick={open}
+          aria-label={t("Show time worked on this page")}
+        >
+          <Text
+            size="xs"
+            c="dimmed"
+            style={{ display: "inline-flex", alignItems: "center", gap: 4 }}
+          >
+            <IconClockHour4 size={14} />
+            {label}
+          </Text>
+        </UnstyledButton>
+      </Tooltip>
+
+      <Modal
+        opened={opened}
+        onClose={close}
+        title={t("Time worked on this article")}
+        size="lg"
+      >
+        <WorkTimePunchCard data={data} />
+      </Modal>
+    </>
+  );
+}
@@ -0,0 +1,82 @@
+/* #395 — 24h × days punch-card. Custom CSS segments on a fixed 24-hour track
+   (position = offset-in-day / 24h, width = duration / 24h), no chart library. */
+
+.row {
+  display: grid;
+  grid-template-columns: 96px 1fr 64px;
+  align-items: center;
+  gap: 12px;
+  padding: 3px 0;
+}
+
+.dayLabel {
+  font-size: var(--mantine-font-size-xs);
+  color: var(--mantine-color-dimmed);
+  white-space: nowrap;
+}
+
+.track {
+  position: relative;
+  height: 16px;
+  border-radius: 4px;
+  background-color: light-dark(
+    var(--mantine-color-gray-1),
+    var(--mantine-color-dark-6)
+  );
+  overflow: hidden;
+}
+
+/* Faint hour grid so the eye can read "morning vs evening". */
+.hourTick {
+  position: absolute;
+  top: 0;
+  bottom: 0;
+  width: 1px;
+  background-color: light-dark(
+    var(--mantine-color-gray-3),
+    var(--mantine-color-dark-4)
+  );
+}
+
+.window {
+  position: absolute;
+  top: 2px;
+  bottom: 2px;
+  border-radius: 3px;
+  min-width: 3px;
+}
+
+.windowWork {
+  background-color: var(--mantine-color-blue-5);
+}
+
+.windowAgent {
+  background-color: var(--mantine-color-grape-5);
+}
+
+/* A lone single-sample (P_single) window: minimal + dimmed, so it neither
+   vanishes nor fakes dense work (§6.2). */
+.windowSingle {
+  opacity: 0.5;
+}
+
+.daySum {
+  font-size: var(--mantine-font-size-xs);
+  text-align: right;
+  white-space: nowrap;
+}
+
+.gapRow {
+  padding: 6px 0 6px 108px;
+  font-size: var(--mantine-font-size-xs);
+  color: var(--mantine-color-dimmed);
+  font-style: italic;
+}
+
+.legendSwatch {
+  display: inline-block;
+  width: 12px;
+  height: 12px;
+  border-radius: 3px;
+  vertical-align: middle;
+}
@@ -0,0 +1,37 @@
+// #395 — client-side mirror of the server work-time payload
+// (apps/server/src/core/page/work-time). Shapes returned by POST /pages/history/time.
+
+export type WorkSessionClass = "work" | "agent_only";
+
+export interface IDayWindow {
+  start: number;
+  end: number;
+  class: WorkSessionClass;
+}
+
+export interface IPerDay {
+  day: number;
+  dayISO: string;
+  activeMs: number;
+  agentMs: number;
+  windows: IDayWindow[];
+}
+
+export interface IWorkTimeConfig {
+  tGap: number;
+  agentTGap: number;
+  pIn: number;
+  pOut: number;
+  pSingle: number;
+  excludeGit: boolean;
+  burstCapMs?: number;
+  dedupRoundMs: number;
+}
+
+export interface IPageWorkTime {
+  workMs: number;
+  agentOnlyMs: number;
+  perDay: IPerDay[];
+  config: IWorkTimeConfig;
+  tz: string;
+}
@@ -51,6 +51,7 @@ import {
 import { formattedDate } from "@/lib/time.ts";
 import { PageEditModeToggle } from "@/features/user/components/page-state-pref.tsx";
 import MovePageModal from "@/features/page/components/move-page-modal.tsx";
+import WorkTimeStat from "@/features/page-history/work-time/work-time-stat.tsx";
 import { useTimeAgo } from "@/hooks/use-time-ago.tsx";
 import {
  useFavoriteIds,
@@ -265,6 +266,8 @@ function PageActionMenu({ readOnly, onSaveVersion }: PageActionMenuProps) {

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

        <VisuallyHidden role="status" aria-live="polite">
@@ -5,6 +5,9 @@ import { IPage } from "@/features/page/types/page.types.ts";

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

 export interface SearchSuggestionParams {
@@ -37,6 +67,10 @@ export interface IPageSearchParams {
  query: string;
  spaceId?: string;
  shareId?: string;
+  // #529 A9: match mode (auto default) + pagination.
+  match?: "auto" | "word" | "prefix" | "substring";
+  limit?: number;
+  offset?: number;
 }

 export interface IAttachmentSearch {
@@ -29,6 +29,7 @@ import ShareAliasSection from "@/features/share/components/share-alias-section.t
 import { useAtom } from "jotai";
 import { workspaceAtom } from "@/features/user/atoms/current-user-atom.ts";
 import { useSpaceQuery } from "@/features/space/queries/space-query.ts";
+import { usePageHistoryListQuery } from "@/features/page-history/queries/page-history-query.ts";

 interface ShareModalProps {
  readOnly: boolean;
@@ -54,6 +55,33 @@ export default function ShareModal({ readOnly }: ShareModalProps) {
  // if level is greater than zero, then it is a descendant page from a shared page
  const isDescendantShared = share && share.level > 0;

+  // #370 Stage B — "publish only the saved version". Mirrors the server XOR:
+  // approved and includeSubPages are mutually exclusive.
+  const isApproved = share?.publishedMode === "approved";
+  const includeSubPages = share?.includeSubPages ?? false;
+
+  // Resolve the latest MANUAL version (the one an approved share publishes) so
+  // the modal can caption it and warn when the live draft has drifted ahead.
+  // Only fetched for a directly-shared page whose modal is actually open.
+  const { data: historyData } = usePageHistoryListQuery(
+    pageIsShared ? pageId : "",
+  );
+  const latestManual = useMemo(() => {
+    const items = historyData?.pages?.flatMap((p) => p.items) ?? [];
+    // The list is newest-first; the first manual row is the published version.
+    return items.find((h) => h.kind === "manual") ?? null;
+  }, [historyData]);
+
+  // The live draft has edits newer than the published saved version when the
+  // page was updated after that manual snapshot was taken.
+  const hasUnpublishedEdits = useMemo(() => {
+    if (!isApproved || !latestManual || !page?.updatedAt) return false;
+    return (
+      new Date(page.updatedAt).getTime() >
+      new Date(latestManual.createdAt).getTime()
+    );
+  }, [isApproved, latestManual, page?.updatedAt]);
+
  const publicLink = `${getAppUrl()}/share/${share?.key}/p/${pageSlug}`;

  const [isPagePublic, setIsPagePublic] = useState<boolean>(false);
@@ -115,6 +143,23 @@ export default function ShareModal({ readOnly }: ShareModalProps) {
    }
  };

+  // #370 Stage B — toggle between publishing the live draft ('live') and the
+  // last saved version ('approved'). The server rejects approved + sub-pages, so
+  // the UI keeps the two toggles mutually exclusive (see the disabled props).
+  const handlePublishedModeChange = async (
+    event: React.ChangeEvent<HTMLInputElement>,
+  ) => {
+    const value = event.currentTarget.checked;
+    try {
+      await updateShareMutation.mutateAsync({
+        shareId: share.id,
+        publishedMode: value ? "approved" : "live",
+      });
+    } catch {
+      // query invalidation will revert the UI
+    }
+  };
+
  const shareLink = useMemo(
    () => (
      <Group my="sm" gap={4} wrap="nowrap">
@@ -238,11 +283,42 @@ export default function ShareModal({ readOnly }: ShareModalProps) {

                  <Switch
                    onChange={handleSubPagesChange}
-                    checked={share.includeSubPages}
+                    checked={includeSubPages}
                    size="xs"
-                    disabled={readOnly}
+                    // XOR with approved mode: a version-frozen share cannot also
+                    // publish a whole sub-tree.
+                    disabled={readOnly || isApproved}
                  />
                </Group>
+                <Group justify="space-between" wrap="nowrap" gap="xl" mt="sm">
+                  <div>
+                    <Text size="sm">
+                      {t("Publish only the saved version")}
+                    </Text>
+                    <Text size="xs" c="dimmed">
+                      {isApproved
+                        ? t(
+                            "Visitors see the last saved version, not live edits",
+                          )
+                        : t("Visitors see live edits as you make them")}
+                    </Text>
+                  </div>
+                  <Switch
+                    onChange={handlePublishedModeChange}
+                    checked={isApproved}
+                    size="xs"
+                    // XOR with sub-pages: hidden intent is enforced by disabling
+                    // this toggle whenever sub-pages are shared.
+                    disabled={readOnly || includeSubPages}
+                  />
+                </Group>
+                {isApproved && hasUnpublishedEdits && (
+                  <Text size="xs" c="orange" mt={4}>
+                    {t(
+                      "You have unsaved changes newer than the published version",
+                    )}
+                  </Text>
+                )}
                <Group justify="space-between" wrap="nowrap" gap="xl" mt="sm">
                  <div>
                    <Text size="sm">{t("Search engine indexing")}</Text>
@@ -6,6 +6,9 @@ export interface IShare {
  pageId: string;
  includeSubPages: boolean;
  searchIndexing: boolean;
+  // #370 Stage B — 'live' serves the current draft; 'approved' serves the last
+  // manually-saved version. Mutually exclusive with includeSubPages.
+  publishedMode: "live" | "approved";
  creatorId: string;
  spaceId: string;
  workspaceId: string;
@@ -75,6 +78,7 @@ export interface ICreateShare {
  pageId?: string;
  includeSubPages?: boolean;
  searchIndexing?: boolean;
+  publishedMode?: "live" | "approved";
 }

 export type IUpdateShare = ICreateShare & { shareId: string; pageId?: string };
@@ -0,0 +1,195 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { render, act, cleanup } from "@testing-library/react";
+import { MemoryRouter, useNavigate } from "react-router-dom";
+
+// Mocks for the dirty shell's side-effecting collaborators.
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: vi.fn() },
+}));
+vi.mock("@/i18n.ts", () => ({ default: { t: (k: string) => k } }));
+vi.mock("@/lib/reload-guard", () => ({
+  hasAutoReloaded: vi.fn(() => false),
+  markAutoReloaded: vi.fn(() => true),
+  recordReloadBreadcrumb: vi.fn(),
+  takeReloadBreadcrumb: vi.fn(() => null),
+}));
+
+import { notifications } from "@mantine/notifications";
+import { hasAutoReloaded, markAutoReloaded } from "@/lib/reload-guard";
+import {
+  triggerGuardedReload,
+  useVersionReloadOnNavigation,
+  __resetGuardedReloadForTests,
+} from "./guarded-reload";
+
+const show = notifications.show as unknown as ReturnType<typeof vi.fn>;
+const mockHasAutoReloaded = hasAutoReloaded as unknown as ReturnType<
+  typeof vi.fn
+>;
+const mockMarkAutoReloaded = markAutoReloaded as unknown as ReturnType<
+  typeof vi.fn
+>;
+
+let reload: ReturnType<typeof vi.fn>;
+let visibility: DocumentVisibilityState;
+
+// Test harness mounted inside a router: it installs the navigation hook and
+// exposes `navigate` so a test can drive an in-app router navigation.
+let doNavigate: (to: string) => void;
+function Harness() {
+  useVersionReloadOnNavigation();
+  const navigate = useNavigate();
+  doNavigate = navigate;
+  return null;
+}
+
+function mountHarness() {
+  render(
+    <MemoryRouter initialEntries={["/start"]}>
+      <Harness />
+    </MemoryRouter>,
+  );
+}
+
+function navigateTo(path: string) {
+  act(() => {
+    doNavigate(path);
+  });
+}
+
+beforeEach(() => {
+  __resetGuardedReloadForTests();
+  vi.clearAllMocks();
+  mockHasAutoReloaded.mockReturnValue(false);
+  mockMarkAutoReloaded.mockReturnValue(true);
+
+  vi.stubGlobal("APP_VERSION", "test-A");
+
+  reload = vi.fn();
+  Object.defineProperty(window, "location", {
+    configurable: true,
+    value: { reload },
+  });
+
+  visibility = "visible";
+  Object.defineProperty(document, "visibilityState", {
+    configurable: true,
+    get: () => visibility,
+  });
+});
+
+afterEach(() => {
+  cleanup();
+  vi.unstubAllGlobals();
+});
+
+describe("triggerGuardedReload (variant C)", () => {
+  it("noop when versions match: no banner, no reload", () => {
+    triggerGuardedReload("test-A");
+    expect(show).not.toHaveBeenCalled();
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("noop when the server version is empty (fail-safe)", () => {
+    triggerGuardedReload("");
+    triggerGuardedReload(undefined);
+    expect(show).not.toHaveBeenCalled();
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("real mismatch shows the banner but does NOT reload immediately", () => {
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(show).toHaveBeenCalledTimes(1);
+    expect(show.mock.calls[0][0]).toMatchObject({
+      id: "app-version-reload",
+      autoClose: false,
+      withCloseButton: true,
+    });
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("reloads EXACTLY ONCE on the first in-app navigation after a mismatch", () => {
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(reload).not.toHaveBeenCalled();
+
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+
+    // A second navigation must NOT reload again (one-shot was consumed).
+    navigateTo("/again");
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("does NOT reload on a 2nd mismatch after the first was armed/consumed (one-shot)", () => {
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+
+    // Another app-version mismatch arrives (reconnect): must not re-arm.
+    triggerGuardedReload("test-C");
+    navigateTo("/again");
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("does NOT reload merely from the tab going to the background", () => {
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(reload).not.toHaveBeenCalled();
+
+    visibility = "hidden";
+    act(() => {
+      document.dispatchEvent(new Event("visibilitychange"));
+    });
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("a hidden-at-receipt tab is also NOT reloaded immediately (variant C uniform); reloads on next navigation", () => {
+    visibility = "hidden";
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(reload).not.toHaveBeenCalled();
+    expect(show).toHaveBeenCalledTimes(1);
+
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("the banner's Update button reloads immediately", () => {
+    triggerGuardedReload("test-B");
+    const message = show.mock.calls[0][0].message as {
+      props: { onClick: () => void };
+    };
+    message.props.onClick();
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("banner-only (auto-reload already spent): banner, never auto-reload on navigation", () => {
+    mockHasAutoReloaded.mockReturnValue(true);
+    mountHarness();
+    triggerGuardedReload("test-B");
+    expect(show).toHaveBeenCalledTimes(1);
+
+    navigateTo("/next");
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("does NOT reload when the flag write fails; falls back to the banner", () => {
+    mockMarkAutoReloaded.mockReturnValue(false);
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).not.toHaveBeenCalled();
+    // performAutoReload falls back to showing the banner (initial + fallback).
+    expect(show).toHaveBeenCalled();
+  });
+
+  it("is idempotent within a tab-load: repeated emits do not stack banners", () => {
+    triggerGuardedReload("test-B");
+    triggerGuardedReload("test-B");
+    triggerGuardedReload("test-C");
+    expect(show).toHaveBeenCalledTimes(1);
+  });
+});
@@ -0,0 +1,188 @@
+import { useEffect, useRef } from "react";
+import { useLocation } from "react-router-dom";
+import { Button } from "@mantine/core";
+import { notifications } from "@mantine/notifications";
+import i18n from "@/i18n.ts";
+import {
+  hasAutoReloaded,
+  markAutoReloaded,
+  recordReloadBreadcrumb,
+  takeReloadBreadcrumb,
+} from "@/lib/reload-guard";
+import { decideVersionAction } from "@/features/user/version-coherence";
+
+// Dirty shell around the pure `decideVersionAction`: it reads globals
+// (APP_VERSION), touches sessionStorage via the shared reload-guard, drives the
+// Mantine notification, and arms the router-navigation reload hook. Kept
+// separate from the pure module so the decision stays unit-testable without a
+// DOM.
+
+// One fixed id so repeated app-version signals (e.g. every reconnect) update a
+// single banner instead of stacking a new one each time.
+const BANNER_ID = "app-version-reload";
+
+// Module-level idempotency for the current tab-load: once a mismatch has been
+// handled we don't re-arm the navigation reload or re-show the banner on
+// subsequent app-version emits.
+let handled = false;
+
+// Variant C: on a real mismatch we do NOT reload the tab when it merely goes to
+// the background (that would silently drop a half-written comment/form). Instead
+// we arm a one-shot reload for the NEXT in-app router navigation — a point where
+// the user is already leaving the current page, so an in-app navigation would
+// discard that unsaved component-state anyway and the reload adds no extra loss.
+let pendingNavReload = false;
+
+// Remembered from the last detected mismatch for the pre-reload breadcrumb and
+// the (already-visible) banner.
+let lastServerVersion = "";
+let lastClientVersion = "";
+
+// Read the build version baked into THIS bundle. The `typeof` guard avoids a
+// ReferenceError where the `APP_VERSION` global is absent (e.g. under vitest,
+// where Vite's `define` did not run) — an unknown client version makes the
+// pure decision no-op (fail-safe).
+function readClientVersion(): string {
+  return (typeof APP_VERSION !== "undefined" ? APP_VERSION : "").trim();
+}
+
+// Perform the actual reload — but only after the shared one-shot flag is
+// persisted. If the write fails (storage unavailable) we must NOT reload
+// (mirrors the reactive chunk-load boundary's `catch → return`), and fall back
+// to the manual banner so the user can still recover.
+function performAutoReload(): void {
+  if (!markAutoReloaded()) {
+    showReloadBanner();
+    return;
+  }
+  // Trace right before the reload (which clears the console): a persistent
+  // breadcrumb + a log line so the auto-reload is observable in a field report.
+  recordReloadBreadcrumb({
+    path: "proactive",
+    serverVersion: lastServerVersion,
+    clientVersion: lastClientVersion,
+  });
+  console.warn(
+    `[version-coherence] auto-reloading: client=${lastClientVersion} -> server=${lastServerVersion}`,
+  );
+  window.location.reload();
+}
+
+function showReloadBanner(): void {
+  notifications.show({
+    id: BANNER_ID,
+    title: i18n.t("A new version is available"),
+    message: (
+      <Button size="xs" mt="xs" onClick={() => performAutoReload()}>
+        {i18n.t("Update")}
+      </Button>
+    ),
+    autoClose: false,
+    withCloseButton: true,
+  });
+}
+
+/**
+ * Handle a server `app-version` announcement: compare it to this bundle's
+ * version and, on a real mismatch, show the banner and arm a guarded reload for
+ * the next in-app navigation (variant C).
+ *
+ * - real mismatch (window budget available) → banner + arm navigation reload.
+ *   The banner's "Update" button reloads immediately (same shared window guard).
+ *   The tab is NOT reloaded on visibility change.
+ * - auto-reload already used this window / storage error → banner only (no arm),
+ *   so there is at most one automatic reload per RELOAD_WINDOW_MS window (loop
+ *   safety).
+ * - in sync / unknown version → noop (fail-safe).
+ */
+export function triggerGuardedReload(
+  rawServerVersion: string | undefined | null,
+): void {
+  const serverVersion = (rawServerVersion ?? "").trim();
+  const clientVersion = readClientVersion();
+
+  // A storage read error surfaces as autoReloadUsed=true → fail toward NOT
+  // reloading (banner only).
+  const autoReloadUsed = hasAutoReloaded();
+
+  const action = decideVersionAction({
+    serverVersion,
+    clientVersion,
+    autoReloadUsed,
+  });
+  if (action === "noop") return;
+
+  // Idempotent per tab-load: don't re-arm or re-stack the banner across repeated
+  // emits (reconnects) once we've already acted.
+  if (handled) return;
+  handled = true;
+
+  lastServerVersion = serverVersion;
+  lastClientVersion = clientVersion;
+
+  if (action === "banner") {
+    // Entered banner-only (permanent skew, node oscillation, or the window's
+    // auto-reload budget already spent). Log for diagnosability; show the banner.
+    console.warn(
+      `[version-coherence] server=${serverVersion} client=${clientVersion}: ` +
+        "auto-reload budget already spent this window — showing manual banner",
+    );
+    showReloadBanner();
+    return;
+  }
+
+  // action === "reload" (variant C): show the banner and defer the auto-reload
+  // to the next in-app navigation instead of reloading now / on visibility.
+  showReloadBanner();
+  pendingNavReload = true;
+}
+
+/**
+ * Consume the armed one-shot navigation reload, if any. Called by
+ * `useVersionReloadOnNavigation` on each in-app router navigation.
+ */
+export function consumeNavigationReload(): void {
+  if (!pendingNavReload) return;
+  pendingNavReload = false;
+  performAutoReload();
+}
+
+/**
+ * Hook (mounted inside the Router) that fires the armed one-shot reload on the
+ * NEXT in-app router navigation after a version mismatch. Skips the initial
+ * render so it only reacts to real navigations, not the first location.
+ */
+export function useVersionReloadOnNavigation(): void {
+  const location = useLocation();
+  const firstRender = useRef(true);
+  useEffect(() => {
+    if (firstRender.current) {
+      firstRender.current = false;
+      return;
+    }
+    consumeNavigationReload();
+  }, [location.key]);
+}
+
+/**
+ * Surface (log once) the breadcrumb left by an auto-reload in the previous page
+ * load — the reload cleared the console, so this makes a "tab reloaded itself"
+ * report diagnosable. Call once on app startup.
+ */
+export function surfacePreviousReloadBreadcrumb(): void {
+  const crumb = takeReloadBreadcrumb();
+  if (!crumb) return;
+  console.info(
+    `[version-coherence] previous auto-reload: path=${crumb.path} ` +
+      `client=${crumb.clientVersion ?? ""} -> server=${crumb.serverVersion ?? ""} ` +
+      `at=${new Date(crumb.at).toISOString()}`,
+  );
+}
+
+// Test-only: reset module-level latches between cases.
+export function __resetGuardedReloadForTests(): void {
+  handled = false;
+  pendingNavReload = false;
+  lastServerVersion = "";
+  lastClientVersion = "";
+}
@@ -0,0 +1,171 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { render, act, cleanup } from "@testing-library/react";
+import { MemoryRouter, useNavigate } from "react-router-dom";
+
+// Integration test for the SHARED, window-based auto-reload budget (invariant a):
+// the reactive chunk-load boundary and the proactive version-coherence path both
+// route through the REAL @/lib/reload-guard, so at most one automatic reload
+// happens per RELOAD_WINDOW_MS across BOTH paths combined. Only the two paths'
+// side-effecting collaborators are mocked — the reload guard is intentionally
+// REAL so this exercises the actual shared sessionStorage budget.
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: vi.fn() },
+}));
+vi.mock("@/i18n.ts", () => ({ default: { t: (k: string) => k } }));
+
+import { handleError } from "@/components/chunk-load-error-boundary";
+import {
+  triggerGuardedReload,
+  useVersionReloadOnNavigation,
+  __resetGuardedReloadForTests,
+} from "./guarded-reload";
+import { RELOAD_WINDOW_MS } from "@/lib/reload-guard";
+
+const CHUNK_ERROR = { name: "ChunkLoadError", message: "boom" };
+const T0 = 1_000_000_000_000;
+
+let reload: ReturnType<typeof vi.fn>;
+let nowMock: ReturnType<typeof vi.spyOn>;
+
+// Harness mounted inside a router: installs the navigation hook and exposes
+// `navigate` so a test can drive an in-app router navigation (the point where the
+// proactive path fires its armed reload).
+let doNavigate: (to: string) => void;
+function Harness() {
+  useVersionReloadOnNavigation();
+  doNavigate = useNavigate();
+  return null;
+}
+function mountHarness() {
+  render(
+    <MemoryRouter initialEntries={["/start"]}>
+      <Harness />
+    </MemoryRouter>,
+  );
+}
+function navigateTo(path: string) {
+  act(() => {
+    doNavigate(path);
+  });
+}
+function setNow(t: number) {
+  nowMock.mockReturnValue(t);
+}
+
+beforeEach(() => {
+  sessionStorage.clear();
+  __resetGuardedReloadForTests();
+  vi.clearAllMocks();
+  nowMock = vi.spyOn(Date, "now").mockReturnValue(T0);
+  vi.stubGlobal("APP_VERSION", "test-A");
+  reload = vi.fn();
+  Object.defineProperty(window, "location", {
+    configurable: true,
+    value: { reload },
+  });
+});
+
+afterEach(() => {
+  cleanup();
+  vi.unstubAllGlobals();
+  vi.restoreAllMocks();
+  sessionStorage.clear();
+});
+
+describe("shared window-based reload budget (invariant a)", () => {
+  it("a chunk-load reload spends the budget: a version-coherence mismatch within the window shows the banner but does NOT reload", () => {
+    // Path 1 (reactive): a stale-chunk 404 auto-reloads once and stamps the window.
+    handleError(CHUNK_ERROR);
+    expect(reload).toHaveBeenCalledTimes(1);
+    reload.mockClear();
+
+    // Path 2 (proactive), 1 min later — still inside the window. The shared budget
+    // is spent, so the version mismatch degrades to the banner and never reloads.
+    setNow(T0 + 60_000);
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("a version-coherence reload spends the SAME budget: a chunk-load error within the window does NOT reload", () => {
+    // Path 2 (proactive) first: real mismatch → arm → fire on navigation.
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+    reload.mockClear();
+
+    // Path 1 (reactive), 2 min later — inside the window. Budget already spent by
+    // the proactive path, so the stale-chunk error must NOT trigger a second reload.
+    setNow(T0 + 2 * 60_000);
+    handleError(CHUNK_ERROR);
+    expect(reload).not.toHaveBeenCalled();
+  });
+
+  it("recovers after the window: a reload strictly older than the window is allowed again (second deploy)", () => {
+    // First auto-reload (reactive) stamps the window.
+    handleError(CHUNK_ERROR);
+    expect(reload).toHaveBeenCalledTimes(1);
+    reload.mockClear();
+
+    // A second deploy arrives after the window has fully elapsed → the proactive
+    // path is allowed to reload again (window, not a permanent one-shot).
+    __resetGuardedReloadForTests();
+    setNow(T0 + RELOAD_WINDOW_MS + 1);
+    mountHarness();
+    triggerGuardedReload("test-B");
+    navigateTo("/next");
+    expect(reload).toHaveBeenCalledTimes(1);
+  });
+
+  it("reactive path fails closed when storage READS but cannot WRITE (quota / Safari private): no unguarded reload", () => {
+    // getItem→null makes hasAutoReloaded() report the budget as available, so
+    // handleError passes the first guard and reaches `if (!markAutoReloaded())
+    // return;`. setItem throws → the stamp cannot stick, so markAutoReloaded()
+    // returns false and that guard MUST bail — otherwise the reactive path would
+    // reload on every stale-chunk error with no persisted budget (an unguarded
+    // loop). This is the asymmetric gap: the proactive path's equivalent is
+    // covered by guarded-reload.test.tsx "does NOT reload when the flag write
+    // fails".
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => null,
+      setItem: () => {
+        throw new Error("quota exceeded");
+      },
+      removeItem: () => {},
+      clear: () => {},
+    });
+    try {
+      handleError(CHUNK_ERROR);
+      expect(reload).not.toHaveBeenCalled();
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+
+  it("sessionStorage unavailable: neither path performs an unguarded reload", () => {
+    // The real guard fails toward NOT reloading when storage throws.
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => {
+        throw new Error("storage disabled");
+      },
+      setItem: () => {
+        throw new Error("storage disabled");
+      },
+      removeItem: () => {},
+      clear: () => {},
+    });
+    try {
+      handleError(CHUNK_ERROR);
+      expect(reload).not.toHaveBeenCalled();
+
+      mountHarness();
+      triggerGuardedReload("test-B");
+      navigateTo("/next");
+      expect(reload).not.toHaveBeenCalled();
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+});
@@ -13,6 +13,12 @@ import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
 import { Error404 } from "@/components/ui/error-404.tsx";
 import { queryClient } from "@/main.tsx";
 import { makeConnectHandler } from "@/features/user/connect-resync.ts";
+import {
+  triggerGuardedReload,
+  useVersionReloadOnNavigation,
+  surfacePreviousReloadBreadcrumb,
+} from "@/features/user/guarded-reload.tsx";
+import type { AppVersionSocketPayload } from "@/features/user/version-coherence.ts";

 export function UserProvider({ children }: React.PropsWithChildren) {
  const [, setCurrentUser] = useAtom(currentUserAtom);
@@ -22,6 +28,16 @@ export function UserProvider({ children }: React.PropsWithChildren) {
  // fetch collab token on load
  const { data: collab } = useCollabToken();

+  // version-coherence: fire the armed one-shot reload on the next in-app
+  // navigation (variant C — a safe point, not on tab backgrounding).
+  useVersionReloadOnNavigation();
+
+  // Surface any breadcrumb left by an auto-reload in the previous page load
+  // (the reload cleared the console) so a field report stays diagnosable.
+  useEffect(() => {
+    surfacePreviousReloadBreadcrumb();
+  }, []);
+
  useEffect(() => {
    if (isLoading || isError) {
      return;
@@ -47,6 +63,16 @@ export function UserProvider({ children }: React.PropsWithChildren) {
      handleConnect();
    });

+    // Register the version-coherence listener SYNCHRONOUSLY, before the socket
+    // connects: the server emits `app-version` immediately in handleConnection,
+    // so a listener attached after connect would miss it on a fast localhost
+    // connect. On a version mismatch the client shows a banner and defers the
+    // auto-reload to the next in-app navigation (variant C — avoids reloading a
+    // backgrounded tab that may hold unsaved input) before it hits a stale chunk.
+    newSocket.on("app-version", (payload?: AppVersionSocketPayload) => {
+      triggerGuardedReload(payload?.version);
+    });
+
    return () => {
      console.log("ws disconnected");
      newSocket.disconnect();
@@ -0,0 +1,64 @@
+import { describe, it, expect } from "vitest";
+import { decideVersionAction } from "./version-coherence";
+
+describe("decideVersionAction", () => {
+  it("noop when the server version is empty (fail-safe)", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "",
+        clientVersion: "v1",
+        autoReloadUsed: false,
+      }),
+    ).toBe("noop");
+  });
+
+  it("noop when the client version is empty (fail-safe)", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "v1",
+        clientVersion: "",
+        autoReloadUsed: false,
+      }),
+    ).toBe("noop");
+  });
+
+  it("noop when versions are equal (in sync)", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "v1",
+        clientVersion: "v1",
+        autoReloadUsed: false,
+      }),
+    ).toBe("noop");
+  });
+
+  it("reload on a real mismatch the first time this session", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "test-B",
+        clientVersion: "test-A",
+        autoReloadUsed: false,
+      }),
+    ).toBe("reload");
+  });
+
+  it("banner on a mismatch once the session auto-reload is spent", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "test-B",
+        clientVersion: "test-A",
+        autoReloadUsed: true,
+      }),
+    ).toBe("banner");
+  });
+
+  it("equal versions stay noop even if auto-reload was already used", () => {
+    expect(
+      decideVersionAction({
+        serverVersion: "v1",
+        clientVersion: "v1",
+        autoReloadUsed: true,
+      }),
+    ).toBe("noop");
+  });
+});
@@ -0,0 +1,32 @@
+// Payload of the per-connect `app-version` socket.io event announced by the
+// server (ws.gateway.ts) after a successful auth. A dedicated event — NOT a
+// member of the room-scoped `WebSocketEvent` union (which is discriminated by
+// `operation`), so it never touches use-query-subscription.
+export type AppVersionSocketPayload = { version: string };
+
+/**
+ * Pure decision for the version-coherence guard.
+ *
+ * All inputs are injected (no globals, no side effects) so it is unit-testable
+ * without a DOM or the build-time `APP_VERSION` global (undefined under vitest).
+ *
+ * - `autoReloadUsed` = an automatic reload has already happened within the
+ *   current ~5-min window, so we must not auto-reload again (loop safety,
+ *   shared window budget with the reactive chunk-load boundary).
+ *
+ * Returns:
+ * - "noop"   — do nothing (unknown version on either side, or already in sync).
+ * - "banner" — show the manual "update available" banner only (no auto-reload).
+ * - "reload" — real first-time mismatch: eligible for a guarded auto-reload.
+ */
+export function decideVersionAction(args: {
+  serverVersion: string;
+  clientVersion: string;
+  autoReloadUsed: boolean;
+}): "reload" | "banner" | "noop" {
+  const { serverVersion, clientVersion, autoReloadUsed } = args;
+  if (!serverVersion || !clientVersion) return "noop"; // fail-safe: unknown version → never act
+  if (serverVersion === clientVersion) return "noop"; // in sync
+  if (autoReloadUsed) return "banner"; // one auto-reload per RELOAD_WINDOW_MS window already spent
+  return "reload"; // real mismatch, window budget available
+}
@@ -0,0 +1,145 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import {
+  hasAutoReloaded,
+  markAutoReloaded,
+  shouldAutoReload,
+  recordReloadBreadcrumb,
+  takeReloadBreadcrumb,
+  RELOAD_WINDOW_MS,
+} from "./reload-guard";
+
+// The shared budget is a single sessionStorage timestamp keyed here; both the
+// reactive chunk-load boundary and the proactive version-coherence path read and
+// stamp it, so at most one auto-reload happens per RELOAD_WINDOW_MS across BOTH.
+const RELOAD_AT_KEY = "chunk-reload-at";
+const NOW = 1_000_000_000_000;
+
+describe("reload-guard", () => {
+  beforeEach(() => {
+    sessionStorage.clear();
+    vi.restoreAllMocks();
+  });
+
+  afterEach(() => {
+    sessionStorage.clear();
+    vi.restoreAllMocks();
+  });
+
+  it("hasAutoReloaded is false before any reload, true within the window after mark", () => {
+    expect(hasAutoReloaded(NOW)).toBe(false);
+    expect(markAutoReloaded(NOW)).toBe(true);
+    // Same key both paths share; stores the reload timestamp, not a flag.
+    expect(sessionStorage.getItem(RELOAD_AT_KEY)).toBe(String(NOW));
+    // Inside the window → budget spent → true (fall through to manual UI).
+    expect(hasAutoReloaded(NOW)).toBe(true);
+    expect(hasAutoReloaded(NOW + RELOAD_WINDOW_MS)).toBe(true);
+  });
+
+  it("hasAutoReloaded is false again once the window has elapsed (a later deploy recovers)", () => {
+    markAutoReloaded(NOW);
+    // Strictly older than the window → a new deploy's mismatch may reload again.
+    expect(hasAutoReloaded(NOW + RELOAD_WINDOW_MS + 1)).toBe(false);
+  });
+
+  it("hasAutoReloaded returns true when reading storage throws (fail toward not reloading)", () => {
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => {
+        throw new Error("storage disabled");
+      },
+      setItem: () => {
+        throw new Error("storage disabled");
+      },
+    });
+    try {
+      expect(hasAutoReloaded()).toBe(true);
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+
+  it("hasAutoReloaded treats an unparseable stored timestamp as never-reloaded", () => {
+    sessionStorage.setItem(RELOAD_AT_KEY, "not-a-number");
+    expect(hasAutoReloaded(NOW)).toBe(false);
+  });
+
+  it("markAutoReloaded returns false when writing storage throws", () => {
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => null,
+      setItem: () => {
+        throw new Error("storage disabled");
+      },
+    });
+    try {
+      expect(markAutoReloaded()).toBe(false);
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+
+  it("records and then takes a breadcrumb once (cleared on read)", () => {
+    recordReloadBreadcrumb({
+      path: "proactive",
+      serverVersion: "test-B",
+      clientVersion: "test-A",
+    });
+    const crumb = takeReloadBreadcrumb();
+    expect(crumb).toMatchObject({
+      path: "proactive",
+      serverVersion: "test-B",
+      clientVersion: "test-A",
+    });
+    expect(typeof crumb?.at).toBe("number");
+    // Cleared on read → a second take returns null.
+    expect(takeReloadBreadcrumb()).toBeNull();
+  });
+
+  it("takeReloadBreadcrumb returns null when nothing was recorded", () => {
+    expect(takeReloadBreadcrumb()).toBeNull();
+  });
+
+  it("recordReloadBreadcrumb swallows a storage-write error (diagnostics only)", () => {
+    vi.stubGlobal("sessionStorage", {
+      getItem: () => null,
+      setItem: () => {
+        throw new Error("storage disabled");
+      },
+      removeItem: () => {},
+    });
+    try {
+      expect(() =>
+        recordReloadBreadcrumb({ path: "chunk-boundary" }),
+      ).not.toThrow();
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+});
+
+// The pure window gate replaces the old one-shot flag: it must permit recovery
+// across several deploys in one tab (each > window apart) while still stopping an
+// infinite reload loop when a lazy chunk is permanently broken (a second failure
+// < window). Moved here from the chunk-load boundary now that it is the shared
+// guard both paths route through.
+describe("shouldAutoReload", () => {
+  const WINDOW = RELOAD_WINDOW_MS;
+
+  it("allows a reload when we have never auto-reloaded", () => {
+    expect(shouldAutoReload(NOW, null, WINDOW)).toBe(true);
+  });
+
+  it("allows a reload when the last one was 6 minutes ago (outside the window)", () => {
+    expect(shouldAutoReload(NOW, NOW - 6 * 60 * 1000, WINDOW)).toBe(true);
+  });
+
+  it("blocks a reload when the last one was 1 minute ago (inside the window)", () => {
+    expect(shouldAutoReload(NOW, NOW - 1 * 60 * 1000, WINDOW)).toBe(false);
+  });
+
+  it("blocks a reload exactly at the window boundary (not strictly older)", () => {
+    expect(shouldAutoReload(NOW, NOW - WINDOW, WINDOW)).toBe(false);
+  });
+
+  it("allows a reload when the stored timestamp is unparseable (NaN)", () => {
+    expect(shouldAutoReload(NOW, NaN, WINDOW)).toBe(true);
+  });
+});
@@ -0,0 +1,121 @@
+// Shared, window-based auto-reload budget.
+//
+// Both auto-reload paths — the reactive chunk-load-error-boundary (recovers
+// AFTER a stale lazy chunk 404s) and the proactive version-coherence feature
+// (reloads BEFORE the tab hits a stale chunk) — go through these functions so
+// they share ONE window-scoped reload budget: at most a single automatic
+// reload per RELOAD_WINDOW_MS across BOTH paths. A window (rather than a
+// permanent one-shot flag) lets a SECOND deploy in the same tab's lifetime
+// recover too, while a permanent skew, node oscillation, or a genuinely-missing
+// chunk still degrades to a manual banner/UI after the first reload instead of
+// looping. When sessionStorage is unavailable every mismatch degrades to the
+// manual UI — no unguarded reload.
+
+// sessionStorage key holding the epoch-ms timestamp of the last automatic reload
+// (shared by both paths).
+const RELOAD_AT_KEY = "chunk-reload-at";
+
+// Allow at most one automatic reload per this window. A stale-deploy 404 is cured
+// by a single reload, so anything inside the window is treated as a reload loop
+// (permanently-broken chunk / permanent skew) and falls through to the manual UI.
+export const RELOAD_WINDOW_MS = 5 * 60 * 1000;
+
+/**
+ * Pure window decision, unit-tested in isolation: auto-reload only if we have
+ * never auto-reloaded (lastReloadAt null/NaN) or the last one was strictly older
+ * than the window. Anything inside the window is suppressed to break an infinite
+ * reload loop.
+ */
+export function shouldAutoReload(
+  now: number,
+  lastReloadAt: number | null,
+  windowMs: number,
+): boolean {
+  if (lastReloadAt === null || Number.isNaN(lastReloadAt)) return true;
+  return now - lastReloadAt > windowMs;
+}
+
+/**
+ * Has an automatic reload already happened within the current window (so the
+ * shared budget is spent right now)? Both paths check this before reloading; a
+ * `true` return means fall through to the manual banner/UI instead of reloading.
+ *
+ * A storage read error (private mode / disabled) is reported as `true` so the
+ * caller fails toward NOT reloading — an unguarded loop is worse than a stale
+ * tab the user can reload manually. Note a window (not a permanent flag): once
+ * the window elapses a later deploy's mismatch is allowed to reload again.
+ */
+export function hasAutoReloaded(now: number = Date.now()): boolean {
+  try {
+    const raw = sessionStorage.getItem(RELOAD_AT_KEY);
+    const lastReloadAt = raw === null ? null : Number.parseInt(raw, 10);
+    return !shouldAutoReload(now, lastReloadAt, RELOAD_WINDOW_MS);
+  } catch {
+    return true;
+  }
+}
+
+/**
+ * Stamp the shared window as consumed now — record that an automatic reload is
+ * being performed within the current RELOAD_WINDOW_MS window.
+ *
+ * Returns whether the write succeeded. A `false` return (storage unavailable)
+ * means the caller MUST NOT reload — otherwise the stamp would never stick and
+ * the reload could loop.
+ */
+export function markAutoReloaded(now: number = Date.now()): boolean {
+  try {
+    sessionStorage.setItem(RELOAD_AT_KEY, String(now));
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+// Diagnostic breadcrumb for an automatic reload. Written right before
+// window.location.reload() (which clears the console) and read back on the next
+// page load, so a "the tab reloaded itself / it's looping" field report is
+// diagnosable: which path fired (proactive version-coherence vs the reactive
+// chunk-load boundary) and which version pair triggered it. sessionStorage
+// survives a same-tab reload, unlike the console.
+const RELOAD_BREADCRUMB_KEY = "reload-breadcrumb";
+
+export type ReloadBreadcrumb = {
+  path: "proactive" | "chunk-boundary";
+  serverVersion?: string;
+  clientVersion?: string;
+  at: number;
+};
+
+/**
+ * Persist a best-effort breadcrumb just before an automatic reload. Failures
+ * (storage unavailable) are swallowed — this is diagnostics only and must never
+ * block or alter the reload decision.
+ */
+export function recordReloadBreadcrumb(
+  entry: Omit<ReloadBreadcrumb, "at">,
+): void {
+  try {
+    sessionStorage.setItem(
+      RELOAD_BREADCRUMB_KEY,
+      JSON.stringify({ ...entry, at: Date.now() }),
+    );
+  } catch {
+    // best-effort diagnostics only
+  }
+}
+
+/**
+ * Read and clear the breadcrumb left by an auto-reload in the previous page
+ * load. Cleared on read so it surfaces exactly once per reload.
+ */
+export function takeReloadBreadcrumb(): ReloadBreadcrumb | null {
+  try {
+    const raw = sessionStorage.getItem(RELOAD_BREADCRUMB_KEY);
+    if (!raw) return null;
+    sessionStorage.removeItem(RELOAD_BREADCRUMB_KEY);
+    return JSON.parse(raw) as ReloadBreadcrumb;
+  } catch {
+    return null;
+  }
+}
@@ -1,7 +1,8 @@
-import { defineConfig, loadEnv } from "vite";
+import { defineConfig, loadEnv, type Plugin } from "vite";
 import react from "@vitejs/plugin-react";
 import { compression } from "vite-plugin-compression2";
 import * as path from "path";
+import * as fs from "node:fs";
 import { execSync } from "node:child_process";

 const envPath = path.resolve(process.cwd(), "..", "..");
@@ -24,7 +25,32 @@ function resolveAppVersion(cwd: string): string {
  }
 }

+// Emit <outDir>/version.json = { "version": appVersion } so the server can read
+// the exact same build id the bundle was compiled with. The value is the SAME
+// `appVersion` fed into `define.APP_VERSION`, so version.json and the baked-in
+// global are identical by construction — the single source of truth (no
+// runtime-env second copy that could drift and cause a false version mismatch).
+function versionJsonPlugin(version: string): Plugin {
+  let outDir = "dist";
+  return {
+    name: "emit-version-json",
+    apply: "build",
+    configResolved(config) {
+      outDir = config.build.outDir;
+    },
+    writeBundle() {
+      const root = path.resolve(process.cwd(), outDir);
+      fs.mkdirSync(root, { recursive: true });
+      fs.writeFileSync(
+        path.join(root, "version.json"),
+        JSON.stringify({ version }),
+      );
+    },
+  };
+}
+
 export default defineConfig(({ mode }) => {
+  const appVersion = resolveAppVersion(envPath);
  const {
    APP_URL,
    FILE_UPLOAD_SIZE_LIMIT,
@@ -52,10 +78,11 @@ export default defineConfig(({ mode }) => {
        POSTHOG_HOST,
        POSTHOG_KEY,
      },
-      APP_VERSION: JSON.stringify(resolveAppVersion(envPath)),
+      APP_VERSION: JSON.stringify(appVersion),
    },
    plugins: [
      react(),
+      versionJsonPlugin(appVersion),
      // Emit .br and .gz next to every built asset so the server can serve the
      // precompressed copy (see @fastify/static preCompressed in static.module.ts).
      compression({
@@ -23,7 +23,7 @@
    "migration:reset": "tsx src/database/migrate.ts down-to NO_MIGRATIONS",
    "migration:codegen": "kysely-codegen --dialect=postgres --camel-case --env-file=../../.env --out-file=./src/database/types/db.d.ts",
    "lint": "eslint \"{src,apps,libs,test}/**/*.ts\" --fix",
-    "pretest": "pnpm --filter @docmost/editor-ext build && pnpm --filter @docmost/prosemirror-markdown build && pnpm --filter @docmost/token-estimate build",
+    "pretest": "pnpm --filter @docmost/editor-ext build && pnpm --filter @docmost/prosemirror-markdown build && pnpm --filter @docmost/token-estimate build && pnpm --filter @docmost/mcp build",
    "test": "jest",
    "test:int": "jest --config test/jest-integration.json",
    "test:watch": "jest --watch",
@@ -141,7 +141,57 @@ export function htmlToJson(html: string) {
  }
 }

-export function jsonToText(tiptapJson: JSONContent) {
+/**
+ * Deterministic text-serializer overrides for the `format:"text"` page read
+ * (#502). Non-text nodes render to a STABLE placeholder instead of their
+ * (structure-dependent) inner text, so a machine diff of two text reads is
+ * driven only by the page's actual prose — output stability across package
+ * versions IS the contract (pinned by a snapshot test). Returning a string from
+ * a `textSerializer` also stops `generateText` descending into the node, so a
+ * table renders as ONE token rather than its flattened cell text.
+ *
+ * Only nodes with no meaningful flat-text form are overridden; every other node
+ * (paragraph/heading/list/code/blockquote/callout/…) keeps its natural text so
+ * a config written as markdown reads back byte-identical.
+ */
+const TEXT_READ_SERIALIZERS: Record<string, (props: { node: any }) => string> =
+  {
+    // Image atom: no inner text -> a fixed placeholder.
+    image: () => '[image]',
+    // Table: `[table RxC]` where R = row count, C = the first row's cell count
+    // (a table's columns are uniform per the schema). Computed from the PM node,
+    // so it is independent of cell contents.
+    table: ({ node }) => {
+      const rows = node?.childCount ?? 0;
+      const cols = rows > 0 ? (node.child(0)?.childCount ?? 0) : 0;
+      return `[table ${rows}x${cols}]`;
+    },
+  };
+
+/**
+ * Serialize a ProseMirror/TipTap document to plain text.
+ *
+ * Default (no options): the long-standing search-index behavior — bare
+ * concatenated node text with `generateText`'s default `\n\n` block separator.
+ * This feeds the page `textContent` tsvector and MUST NOT change.
+ *
+ * `deterministic:true` (#502 `format:"text"` page read): a flat, machine-diffable
+ * rendering — one line per block (`\n` block separator; `hardBreak` already
+ * serializes to `\n`), inline marks/anchors/autoformat dropped, and non-text
+ * nodes replaced by the stable placeholders above (`[image]`, `[table RxC]`).
+ */
+export function jsonToText(
+  // `any` (like jsonToHtml/jsonToMarkdown) so a loosely-typed DB `page.content`
+  // (JsonValue) can be passed straight through, as the controller does.
+  tiptapJson: any,
+  options?: { deterministic?: boolean },
+) {
+  if (options?.deterministic) {
+    return generateText(tiptapJson, tiptapExtensions, {
+      blockSeparator: '\n',
+      textSerializers: TEXT_READ_SERIALIZERS,
+    });
+  }
  return generateText(tiptapJson, tiptapExtensions);
 }

@@ -0,0 +1,116 @@
+import { jsonToText } from './collaboration.util';
+
+// #502 READ contract: `jsonToText(json, { deterministic: true })` — the flat,
+// machine-diffable text rendering behind getPage `format:"text"`. Block-per-line
+// (`\n` separator), inline marks/anchors dropped, hardBreak -> `\n`, and non-text
+// nodes replaced by STABLE placeholders (`[image]`, `[table RxC]`). Output
+// stability across package versions IS the contract, so it is pinned by a
+// snapshot below. The DEFAULT (no options) path is the search-index serializer
+// and MUST be unchanged — asserted separately.
+
+const doc = (...content: any[]) => ({ type: 'doc', content });
+const para = (...content: any[]) => ({ type: 'paragraph', content });
+const text = (t: string, marks?: any[]) =>
+  marks ? { type: 'text', text: t, marks } : { type: 'text', text: t };
+
+describe('jsonToText — default (search index) behavior is unchanged', () => {
+  it('uses the `\\n\\n` block separator and drops non-text nodes to empty', () => {
+    const d = doc(para(text('alpha')), para(text('beta')));
+    expect(jsonToText(d)).toBe('alpha\n\nbeta');
+  });
+
+  it('an image contributes no text in the default (tsvector) mode', () => {
+    const d = doc(para(text('cap')), { type: 'image', attrs: { src: 's' } });
+    // No `[image]` placeholder leaks into the search index.
+    expect(jsonToText(d)).not.toContain('[image]');
+  });
+});
+
+describe('jsonToText — deterministic:true (getPage format:"text")', () => {
+  it('renders one line per block with `\\n` separators, marks dropped', () => {
+    const d = doc(
+      { type: 'heading', attrs: { level: 2 }, content: [text('Title')] },
+      para(
+        text('hello ', [{ type: 'bold' }]),
+        text('world', [{ type: 'italic' }]),
+      ),
+    );
+    expect(jsonToText(d, { deterministic: true })).toBe('Title\nhello world');
+  });
+
+  it('a hardBreak renders as a newline', () => {
+    const d = doc(para(text('a'), { type: 'hardBreak' }, text('b')));
+    expect(jsonToText(d, { deterministic: true })).toBe('a\nb');
+  });
+
+  it('an image node -> the stable `[image]` placeholder', () => {
+    const d = doc(para(text('before')), { type: 'image', attrs: { src: 's' } });
+    expect(jsonToText(d, { deterministic: true })).toBe('before\n[image]');
+  });
+
+  it('a table -> `[table RxC]` (rows x columns) and its cell text is NOT flattened in', () => {
+    const cell = (t: string) => ({
+      type: 'tableCell',
+      content: [para(text(t))],
+    });
+    const row = (...cells: any[]) => ({ type: 'tableRow', content: cells });
+    const table = {
+      type: 'table',
+      content: [
+        row(cell('CELLONE'), cell('CELLTWO'), cell('CELLTHREE')),
+        row(cell('CELLFOUR'), cell('CELLFIVE'), cell('CELLSIX')),
+      ],
+    };
+    const d = doc(para(text('grid:')), table);
+    const out = jsonToText(d, { deterministic: true });
+    expect(out).toBe('grid:\n[table 2x3]');
+    expect(out).not.toContain('CELL'); // cell text is not flattened into the read
+  });
+
+  it('SNAPSHOT: a mixed document renders to a stable, deterministic string', () => {
+    const cell = (t: string) => ({
+      type: 'tableCell',
+      content: [para(text(t))],
+    });
+    const d = doc(
+      { type: 'heading', attrs: { level: 1 }, content: [text('Config')] },
+      para(text('key = ', [{ type: 'bold' }]), text('value')),
+      {
+        type: 'bulletList',
+        content: [
+          { type: 'listItem', content: [para(text('one'))] },
+          { type: 'listItem', content: [para(text('two'))] },
+        ],
+      },
+      { type: 'image', attrs: { src: 's' } },
+      {
+        type: 'table',
+        content: [{ type: 'tableRow', content: [cell('x'), cell('y')] }],
+      },
+    );
+    expect(jsonToText(d, { deterministic: true })).toMatchInlineSnapshot(`
+     "Config
+     key = value
+
+
+     one
+
+     two
+     [image]
+     [table 1x2]"
+    `);
+  });
+
+  it('SCENARIO: a config written as a code block reads back byte-identical (diff empty)', () => {
+    const config =
+      'export TICKET_LIFETIME=$2592000\nservers:\n  - www.internal.host';
+    const d = doc({
+      type: 'codeBlock',
+      attrs: { language: 'yaml' },
+      content: [text(config)],
+    });
+    // The code block is one block; its text (dollars, bare domain, newlines) is
+    // preserved verbatim, so a read-as-text of a stored config diffs empty.
+    expect(jsonToText(d, { deterministic: true })).toBe(config);
+  });
+});
@@ -0,0 +1,52 @@
+import { join } from 'path';
+import * as fs from 'node:fs';
+import * as os from 'node:os';
+import { readClientBuildVersion } from './client-version';
+
+describe('readClientBuildVersion', () => {
+  let dir: string;
+
+  beforeEach(() => {
+    dir = fs.mkdtempSync(join(os.tmpdir(), 'client-version-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(dir, { recursive: true, force: true });
+  });
+
+  const writeVersionJson = (content: string) =>
+    fs.writeFileSync(join(dir, 'version.json'), content);
+
+  it('returns the version from a valid version.json', () => {
+    writeVersionJson(JSON.stringify({ version: 'test-A' }));
+    expect(readClientBuildVersion(dir)).toBe('test-A');
+  });
+
+  it('trims surrounding whitespace in the version', () => {
+    writeVersionJson(JSON.stringify({ version: '  v1.2.3  ' }));
+    expect(readClientBuildVersion(dir)).toBe('v1.2.3');
+  });
+
+  it('returns "" when version.json is missing', () => {
+    expect(readClientBuildVersion(dir)).toBe('');
+  });
+
+  it('returns "" on malformed JSON', () => {
+    writeVersionJson('{ not json');
+    expect(readClientBuildVersion(dir)).toBe('');
+  });
+
+  it('returns "" when the version field is absent', () => {
+    writeVersionJson(JSON.stringify({ notVersion: 'x' }));
+    expect(readClientBuildVersion(dir)).toBe('');
+  });
+
+  it('returns "" when the version field is not a string', () => {
+    writeVersionJson(JSON.stringify({ version: 123 }));
+    expect(readClientBuildVersion(dir)).toBe('');
+  });
+
+  it('returns "" when the path does not exist at all', () => {
+    expect(readClientBuildVersion(join(dir, 'nope'))).toBe('');
+  });
+});
@@ -0,0 +1,36 @@
+import { join } from 'path';
+import * as fs from 'node:fs';
+
+/**
+ * Resolve the absolute path to the built client bundle directory
+ * (`apps/client/dist`) shipped into the runtime image.
+ *
+ * The `../` depth is anchored on THIS module's compiled location
+ * (`dist/common/helpers`). `integrations/static` sits at the same depth under
+ * the compiled root, so both callers (StaticModule and readClientBuildVersion)
+ * MUST share this single helper rather than duplicating the depth — a copy in a
+ * module at a different depth would silently resolve to the wrong directory.
+ */
+export function resolveClientDistPath(): string {
+  return join(__dirname, '..', '..', '..', '..', 'client/dist');
+}
+
+/**
+ * Read the build version the client bundle was compiled with, from
+ * `<clientDistPath>/version.json` (written by the Vite build — the single
+ * source of truth shared by the baked-in `APP_VERSION` global and this file).
+ *
+ * Fail-safe: any error (missing file, unreadable, bad JSON, non-string
+ * version) yields `''`. The caller treats an empty version as "unknown" and
+ * the whole version-coherence feature stays silently inert — existing deploys
+ * without the file keep working unchanged.
+ */
+export function readClientBuildVersion(clientDistPath: string): string {
+  try {
+    const raw = fs.readFileSync(join(clientDistPath, 'version.json'), 'utf8');
+    const version = (JSON.parse(raw) as { version?: unknown }).version;
+    return typeof version === 'string' ? version.trim() : '';
+  } catch {
+    return '';
+  }
+}
@@ -3,3 +3,4 @@ export * from './nanoid.utils';
 export * from './file.helper';
 export * from './constants';
 export * from './security-headers';
+export * from './client-version';
@@ -35,6 +35,7 @@ import {
 import { PaginationOptions } from '@docmost/db/pagination/pagination-options';
 import { AiChatRepo } from '@docmost/db/repos/ai-chat/ai-chat.repo';
 import { AiChatMessageRepo } from '@docmost/db/repos/ai-chat/ai-chat-message.repo';
+import { AiChatRunStepRepo } from '@docmost/db/repos/ai-chat/ai-chat-run-step.repo';
 import { PageRepo } from '@docmost/db/repos/page/page.repo';
 import { UserThrottlerGuard } from '../../integrations/throttle/user-throttler.guard';
 import { AI_CHAT_THROTTLER } from '../../integrations/throttle/throttler-names';
@@ -43,6 +44,8 @@ import {
  AiChatRunHooks,
  AiChatService,
  AiChatStreamBody,
+  rowHasInlineParts,
+  hydrateAssistantParts,
 } from './ai-chat.service';
 import { AiChatRunService } from './ai-chat-run.service';
 import { AiTranscriptionService } from './ai-transcription.service';
@@ -129,8 +132,39 @@ export class AiChatController {
    // production. Only touched on the resumable-stream (flag-on) path.
    private readonly streamRegistry?: AiChatStreamRegistryService,
    private readonly environment?: EnvironmentService,
+    // #492: reconstruct a #492 mid-run record's parts from the steps table before
+    // returning rows to the client / export. OPTIONAL so positional controller
+    // specs compile unchanged; when absent, hydration is skipped (old-era rows
+    // already carry inline parts, so nothing to reconstruct).
+    private readonly aiChatRunStepRepo?: AiChatRunStepRepo,
  ) {}

+  /**
+   * Reconstruct parts for any assistant rows that don't carry them INLINE — a
+   * #492 mid-run record whose per-step parts live in `ai_chat_run_steps` (the
+   * append-persist backend). Every FINISHED row (old-era + #492) and every old-era
+   * streaming snapshot already has inline `metadata.parts`, so the common path
+   * fetches NOTHING and returns the rows untouched; only an actively-streaming
+   * new-style row triggers the batch step fetch. Consumers (seed/poll/export) read
+   * `metadata.parts` off the returned rows exactly as before — the era switch is
+   * invisible to them (reconstructRunParts contract).
+   */
+  private async withReconstructedParts(
+    rows: AiChatMessage[],
+    workspaceId: string,
+  ): Promise<AiChatMessage[]> {
+    if (!this.aiChatRunStepRepo) return rows;
+    const needy = rows.filter(
+      (r) => r.role === 'assistant' && !rowHasInlineParts(r),
+    );
+    if (needy.length === 0) return rows;
+    const stepsByMessage = await this.aiChatRunStepRepo.findByMessageIds(
+      needy.map((r) => r.id),
+      workspaceId,
+    );
+    return hydrateAssistantParts(rows, stepsByMessage);
+  }
+
  /** List the requesting user's chats in this workspace (paginated). */
  @HttpCode(HttpStatus.OK)
  @Post('chats')
@@ -184,11 +218,17 @@ export class AiChatController {
    @AuthWorkspace() workspace: Workspace,
  ) {
    await this.assertOwnedChat(dto.chatId, user, workspace);
-    return this.aiChatMessageRepo.findByChat(
+    const page = await this.aiChatMessageRepo.findByChat(
      dto.chatId,
      workspace.id,
      pagination,
    );
+    // #492: reconstruct parts for any active new-style row so the client seed sees
+    // `metadata.parts` unchanged (a no-op for the finished rows that fill a page).
+    return {
+      ...page,
+      items: await this.withReconstructedParts(page.items, workspace.id),
+    };
  }

  /**
@@ -225,7 +265,10 @@ export class AiChatController {
      workspace.id,
    );
    return {
-      rows,
+      // #492: the delta of an actively-streaming new-style row carries its parts
+      // reconstructed from the steps table, so the degraded poll shows persisted
+      // progress exactly as the pre-#492 full-row snapshot did.
+      rows: await this.withReconstructedParts(rows, workspace.id),
      cursor,
      run: run ? { id: run.id, status: run.status } : null,
    };
@@ -247,8 +290,10 @@ export class AiChatController {
    @AuthWorkspace() workspace: Workspace,
  ): Promise<{ markdown: string }> {
    const chat = await this.assertOwnedChat(dto.chatId, user, workspace);
-    const rows = await this.aiChatMessageRepo.findAllByChat(
-      dto.chatId,
+    const rows = await this.withReconstructedParts(
+      await this.aiChatMessageRepo.findAllByChat(dto.chatId, workspace.id),
+      // #492: an interrupted-but-still-active turn exports its persisted steps
+      // (reconstructed from the steps table) just like the pre-#492 full row did.
      workspace.id,
    );
    const markdown = buildChatMarkdown({
@@ -288,7 +333,13 @@ export class AiChatController {
          workspace.id,
        )
      : undefined;
-    return { run, message: message ?? null };
+    // #492: reconnect to an IN-FLIGHT run reconstructs the projection row's parts
+    // from the steps table (the row itself carries only the step marker mid-run);
+    // a finished run's row already has inline parts, so this is a no-op.
+    const [hydrated] = message
+      ? await this.withReconstructedParts([message], workspace.id)
+      : [undefined];
+    return { run, message: hydrated ?? null };
  }

  /**
@@ -370,10 +370,12 @@ describe('AiChatService.stream — abortSignal wiring (#184 F3)', () => {
    );
  });

-  // #490 reactive branch: a provider CONTEXT-OVERFLOW 400 in onError is classified,
-  // records a distinguishable cause, and stamps metadata.replayOverflow so the NEXT
-  // turn's budgeter trims aggressively (the recovery that un-bricks the chat).
-  it('#490: a context-overflow 400 stamps replayOverflow on the finalized row', async () => {
+  // #490/#520 reactive branch: a provider CONTEXT-OVERFLOW 400 in onError is
+  // classified, records a distinguishable cause, and stamps the consecutive-overflow
+  // COUNTER (metadata.replayOverflowCount) so the NEXT turn's budgeter trims with
+  // escalating aggression (the recovery that un-bricks the chat). This is a fresh
+  // chat (empty history -> prior streak 0), so the first overflow stamps count 1.
+  it('#490/#520: a context-overflow 400 stamps replayOverflowCount=1 on the finalized row', async () => {
    jest
      .spyOn(Logger.prototype, 'error')
      .mockImplementation(() => undefined as never);
@@ -397,11 +399,14 @@ describe('AiChatService.stream — abortSignal wiring (#184 F3)', () => {
      metadata: Record<string, unknown>;
    };
    expect(patch.status).toBe('error');
-    expect(patch.metadata.replayOverflow).toBe(true);
+    // First overflow on a fresh chat -> k = prior(0) + 1 = 1.
+    expect(patch.metadata.replayOverflowCount).toBe(1);
+    // The legacy boolean is no longer written (the counter supersedes it).
+    expect('replayOverflow' in patch.metadata).toBe(false);
    expect(patch.metadata.error).toContain('контекстное окно');
  });

-  it('#490: a non-overflow error does NOT stamp replayOverflow', async () => {
+  it('#490/#520: a non-overflow error does NOT stamp the overflow counter', async () => {
    jest
      .spyOn(Logger.prototype, 'error')
      .mockImplementation(() => undefined as never);
@@ -412,6 +417,7 @@ describe('AiChatService.stream — abortSignal wiring (#184 F3)', () => {
      status: string;
      metadata: Record<string, unknown>;
    };
+    expect('replayOverflowCount' in patch.metadata).toBe(false);
    expect('replayOverflow' in patch.metadata).toBe(false);
  });
 });
@@ -30,13 +30,16 @@ import {
  STEP_LIMIT_NO_ANSWER_MARKER,
  OUTPUT_DEGENERATION_ERROR,
  lastAssistantContextTokens,
-  lastAssistantReplayOverflow,
+  lastAssistantReplayOverflowCount,
  seedActivatedTools,
 } from './ai-chat.service';
 import type { AiChatMessage, Workspace } from '@docmost/db/types/entity.types';
 import { buildSystemPrompt } from './ai-chat.prompt';
 import type { McpClientsService } from './external-mcp/mcp-clients.service';
-import { resolveEffectiveReplayThreshold } from './history-budget';
+import {
+  resolveEffectiveReplayThreshold,
+  REPLAY_MIN_FLOOR_TOKENS,
+} from './history-budget';

 /**
 * Unit tests for compactToolOutput: the pure helper that shrinks tool outputs
@@ -554,49 +557,129 @@ describe('seedActivatedTools', () => {
  });
 });

-describe('lastAssistantReplayOverflow', () => {
+describe('lastAssistantReplayOverflowCount', () => {
  const row = (
    role: string,
    metadata: Record<string, unknown> | null,
  ): AiChatMessage => ({ role, metadata }) as unknown as AiChatMessage;

-  it('is true only when the LAST assistant turn overflowed', () => {
+  it('reads the consecutive-overflow count from the LAST assistant turn', () => {
    expect(
-      lastAssistantReplayOverflow([
-        row('assistant', { replayOverflow: true }),
+      lastAssistantReplayOverflowCount([
+        row('assistant', { replayOverflowCount: 3 }),
        row('user', null),
      ]),
-    ).toBe(true);
-    // A recovered (later, non-overflow) assistant turn clears it.
+    ).toBe(3);
+    // A recovered (later, non-overflow) assistant turn resets it to 0 — the read
+    // stops at the most recent assistant row, which carries no count.
    expect(
-      lastAssistantReplayOverflow([
-        row('assistant', { replayOverflow: true }),
+      lastAssistantReplayOverflowCount([
+        row('assistant', { replayOverflowCount: 3 }),
        row('user', null),
        row('assistant', { contextTokens: 5 }),
      ]),
-    ).toBe(false);
-    expect(lastAssistantReplayOverflow([])).toBe(false);
+    ).toBe(0);
+    expect(lastAssistantReplayOverflowCount([])).toBe(0);
  });

-  // #490 reactive recovery: a prior turn stamped `replayOverflow` must make the
-  // NEXT turn's effective budget the AGGRESSIVE 0.5x cut — that harder trim is
-  // what un-bricks a chat that just 400'd on the context window. This exercises
-  // the exact wiring the service uses: read the stamp, then scale the threshold.
-  it('#490: a prior replayOverflow drives the next turn to the 0.5x aggressive budget', () => {
+  // BACK-COMPAT (#520): an in-flight row written by the pre-#520 boolean stamp
+  // (`replayOverflow: true`, no count) reads as k=1 — the old single 0.5× behavior —
+  // so a chat mid-recovery across the deploy does not regress.
+  it('#520 back-compat: a legacy boolean replayOverflow reads as k=1', () => {
+    expect(
+      lastAssistantReplayOverflowCount([
+        row('assistant', { replayOverflow: true }),
+        row('user', null),
+      ]),
+    ).toBe(1);
+    // A legacy row with the flag absent/false is k=0.
+    expect(
+      lastAssistantReplayOverflowCount([row('assistant', { contextTokens: 5 })]),
+    ).toBe(0);
+  });
+
+  // A corrupt/negative persisted count never yields a negative k.
+  it('clamps a corrupt negative count to 0', () => {
+    expect(
+      lastAssistantReplayOverflowCount([
+        row('assistant', { replayOverflowCount: -4 }),
+      ]),
+    ).toBe(0);
+  });
+
+  // #490/#520 reactive recovery: the prior consecutive-overflow count `k` drives
+  // the next turn's effective budget to an ESCALATING cut (0.5**k) — each further
+  // consecutive 400 tightens it, which is what un-bricks a chat that keeps
+  // overflowing. This exercises the exact wiring the service uses: read the count,
+  // then scale the threshold.
+  it('#490/#520: the prior count drives the next turn to the escalating aggressive budget', () => {
    const history = [
-      row('assistant', { replayOverflow: true }),
+      row('assistant', { replayOverflowCount: 1 }),
      row('user', null),
    ];
-    const priorOverflowed = lastAssistantReplayOverflow(history);
-    expect(priorOverflowed).toBe(true);
-    // Base budget 100k -> aggressive recovery halves it to 50k this turn.
-    expect(resolveEffectiveReplayThreshold(100_000, priorOverflowed)).toBe(50_000);
+    const k = lastAssistantReplayOverflowCount(history);
+    expect(k).toBe(1);
+    // Base budget 100k -> first-overflow recovery halves it to 50k this turn.
+    expect(resolveEffectiveReplayThreshold(100_000, k)).toBe(50_000);
+    // A second consecutive overflow (k=2) quarters it.
+    expect(resolveEffectiveReplayThreshold(100_000, 2)).toBe(25_000);
    // Odd base floors, not rounds.
-    expect(resolveEffectiveReplayThreshold(99_999, true)).toBe(49_999);
-    // No prior overflow -> the base budget is used verbatim (no aggressive cut).
-    expect(resolveEffectiveReplayThreshold(100_000, false)).toBe(100_000);
+    expect(resolveEffectiveReplayThreshold(99_999, 1)).toBe(49_999);
+    // No prior overflow (k=0) -> the base budget is used verbatim (no cut).
+    expect(resolveEffectiveReplayThreshold(100_000, 0)).toBe(100_000);
    // An explicit off-switch (null) is never overridden, even on recovery.
-    expect(resolveEffectiveReplayThreshold(null, true)).toBeNull();
+    expect(resolveEffectiveReplayThreshold(null, 3)).toBeNull();
+  });
+
+  // #520 escalation table + convergence: the cut deepens each consecutive overflow
+  // and is CLAMPED at the floor so it converges (un-bricks even against a small
+  // real window), instead of the old fixed single 0.5× that stuck at 50k forever.
+  it('#520: escalates and converges to the floor, un-bricking a small real window', () => {
+    const base = 100_000;
+    expect(resolveEffectiveReplayThreshold(base, 0)).toBe(base);
+    expect(resolveEffectiveReplayThreshold(base, 1)).toBe(50_000);
+    expect(resolveEffectiveReplayThreshold(base, 2)).toBe(25_000);
+    expect(resolveEffectiveReplayThreshold(base, 3)).toBe(12_500);
+
+    // Residual-brick regression (#520): with the flat-default base (100k) and a real
+    // model window of ~40k, the OLD fixed 0.5× stuck at 50k forever (> 40k -> 400s
+    // again, never recovers). The escalating cut drops BELOW 40k after enough
+    // consecutive overflows -> the history finally fits -> the chat un-bricks.
+    const realWindow = 40_000;
+    // k=1 (50k) still exceeds the window — the old behavior's terminal state.
+    expect(resolveEffectiveReplayThreshold(base, 1)).toBeGreaterThan(realWindow);
+    // But escalation converges under the window within a couple more turns.
+    const converged = [2, 3, 4, 5].some(
+      (k) => (resolveEffectiveReplayThreshold(base, k) as number) < realWindow,
+    );
+    expect(converged).toBe(true);
+
+    // Convergence is bounded BELOW by the floor: a large k never trims below it.
+    for (const k of [4, 8, 20, 100]) {
+      expect(resolveEffectiveReplayThreshold(base, k)).toBe(REPLAY_MIN_FLOOR_TOKENS);
+      expect(
+        resolveEffectiveReplayThreshold(base, k) as number,
+      ).toBeGreaterThanOrEqual(REPLAY_MIN_FLOOR_TOKENS);
+    }
+  });
+
+  // The floor never RAISES a legitimately small configured budget above itself —
+  // that would re-overflow the very window it was configured for. Under #520 Option B
+  // recovery MAY cut it BELOW itself (down to floor(0.5×base) = the old 0.5× cut).
+  it('#520: never inflates a small configured budget above itself (may cut below)', () => {
+    const small = 5_000; // below the floor
+    const floor = Math.min(REPLAY_MIN_FLOOR_TOKENS, Math.floor(small * 0.5)); // 2500
+    expect(resolveEffectiveReplayThreshold(small, 0)).toBe(small);
+    // Even under escalation the effective threshold never exceeds the base, and never
+    // drops below the absolute floor.
+    for (const k of [1, 2, 3, 10]) {
+      const t = resolveEffectiveReplayThreshold(small, k) as number;
+      expect(t).toBeLessThanOrEqual(small);
+      expect(t).toBeGreaterThanOrEqual(floor);
+    }
+    // Option B: on overflow it DOES cut below the configured budget (old floor==budget
+    // behavior would keep this at `small`).
+    expect(resolveEffectiveReplayThreshold(small, 1)).toBe(floor);
  });
 });

@@ -930,21 +1013,50 @@ describe('flushAssistant', () => {
    expect(flushed.metadata.error).toBe('boom');
  });

-  // #490 observability: the replay budgeter's decision is stamped on the turn.
-  it('records replayTrimmedToTokens + replayOverflow when provided', () => {
+  // #490/#520 observability: the replay budgeter's decision is stamped on the turn,
+  // now including the consecutive-overflow COUNTER (#520) the next turn escalates on.
+  it('records replayTrimmedToTokens + replayOverflowCount when provided', () => {
    const f = flushAssistant([], '', 'error', {
      error: 'ctx',
      replayTrimmedToTokens: 42_000,
-      replayOverflow: true,
+      replayOverflowCount: 2,
    });
    expect(f.metadata.replayTrimmedToTokens).toBe(42_000);
-    expect(f.metadata.replayOverflow).toBe(true);
+    expect(f.metadata.replayOverflowCount).toBe(2);
  });

  it('omits the replay metadata when not provided', () => {
    const f = flushAssistant([], '', 'completed', { finishReason: 'stop' });
    expect('replayTrimmedToTokens' in f.metadata).toBe(false);
-    expect('replayOverflow' in f.metadata).toBe(false);
+    expect('replayOverflowCount' in f.metadata).toBe(false);
+    expect('replayBelowConfiguredBudget' in f.metadata).toBe(false);
+  });
+
+  // #520 Option B observability: the turn is marked when recovery replayed BELOW the
+  // admin-configured budget, so the UI/telemetry can surface "config too large".
+  it('stamps replayBelowConfiguredBudget when recovery cut below the configured budget', () => {
+    const f = flushAssistant([], '', 'error', {
+      error: 'ctx',
+      replayOverflowCount: 2,
+      replayBelowConfiguredBudget: true,
+    });
+    // MUTATION SENTINEL: dropping the metadata stamp in flushAssistant reddens this.
+    expect(f.metadata.replayBelowConfiguredBudget).toBe(true);
+  });
+
+  it('omits replayBelowConfiguredBudget on a normal in-budget replay', () => {
+    // false/omitted must NOT leave the flag on the turn (only the below-budget case).
+    const off = flushAssistant([], '', 'completed', {
+      replayBelowConfiguredBudget: false,
+    });
+    expect('replayBelowConfiguredBudget' in off.metadata).toBe(false);
+  });
+
+  // A clean finalize (no overflow -> count 0/omitted) leaves NO counter, which the
+  // next turn reads as k=0 — the reset that ends a recovery streak.
+  it('omits replayOverflowCount for a zero/absent count (reset semantics)', () => {
+    const zero = flushAssistant([], '', 'completed', { replayOverflowCount: 0 });
+    expect('replayOverflowCount' in zero.metadata).toBe(false);
  });

  // #274 observability: the page-change diff the agent saw this turn is persisted
@@ -22,6 +22,7 @@ import { AiSettingsService } from '../../integrations/ai/ai-settings.service';
 import { describeProviderError } from '../../integrations/ai/ai-error.util';
 import { AiChatRepo } from '@docmost/db/repos/ai-chat/ai-chat.repo';
 import { AiChatMessageRepo } from '@docmost/db/repos/ai-chat/ai-chat-message.repo';
+import { AiChatRunStepRepo } from '@docmost/db/repos/ai-chat/ai-chat-run-step.repo';
 import { AiChatPageSnapshotRepo } from '@docmost/db/repos/ai-chat/ai-chat-page-snapshot.repo';
 import { AiAgentRoleRepo } from '@docmost/db/repos/ai-agent-roles/ai-agent-roles.repo';
 import { PageRepo } from '@docmost/db/repos/page/page.repo';
@@ -140,9 +141,10 @@ const OUTPUT_DEGENERATION_ERROR =

 // Prefix recorded on the assistant row when the provider rejected the turn for
 // CONTEXT OVERFLOW (#490): the replayed history exceeded the model's window. The
-// row is ALSO stamped `metadata.replayOverflow` so the NEXT turn's budgeter trims
-// aggressively (the reactive recovery — the overflowing turn had no usage signal
-// to trigger preventive trimming, so the classified 400 is what un-bricks it).
+// row is ALSO stamped `metadata.replayOverflowCount` (the consecutive-overflow
+// counter, #520) so the NEXT turn's budgeter trims with escalating aggression (the
+// reactive recovery — the overflowing turn had no usage signal to trigger
+// preventive trimming, so the classified 400 is what un-bricks it).
 export const CONTEXT_OVERFLOW_ERROR_PREFIX =
  'Диалог превысил контекстное окно модели; история будет агрессивно ' +
  'сокращена на следующем ходу.';
@@ -189,10 +191,11 @@ export function stepBudgetWarning(stepNumber: number): string {
 //
 // `system` is the in-scope system prompt; we CONCATENATE so the original
 // persona/context is preserved — a bare `system` override would REPLACE the
-// whole system prompt for the step. `activatedTools` is PER-TURN mutable state
-// owned by the streaming loop (a closure Set grown by loadTools); it is passed
-// in (not module-global, not persisted) so this stays a pure function of its
-// arguments.
+// whole system prompt for the step. `activatedTools` is a closure Set grown by
+// loadTools and owned by the streaming loop; the caller seeds it from and
+// persists it to the chat's metadata across turns (#490), but this function only
+// READS the Set it is handed, so it stays a pure function of its arguments (not
+// module-global).
 //
 // NOTE: at AI SDK v7 the per-step `system` field is renamed to `instructions`.
 // On v6 (`^6.0.134`) `system` is the correct field — adjust when bumping.
@@ -517,6 +520,12 @@ export class AiChatService implements OnModuleInit, OnModuleDestroy {
    // constructions compile unchanged; Nest always injects the real singleton, so
    // reconcile sees the SAME in-memory active/zombie maps the runner mutates.
    private readonly aiChatRunService?: AiChatRunService,
+    // #492 append-persist: per-step INSERT into the lightweight steps table (the
+    // O(Σ steps) replacement for the O(n²) full-row `metadata.parts` rewrite).
+    // OPTIONAL so existing positional constructions (int-specs) compile unchanged;
+    // Nest injects the real singleton. When ABSENT the per-step path falls back to
+    // the pre-#492 full-row flush (no regression, only no WAL win).
+    private readonly aiChatRunStepRepo?: AiChatRunStepRepo,
  ) {}

  // #487: periodic reconcile timer (single-process phase 1). Started in
@@ -1113,8 +1122,34 @@ export class AiChatService implements OnModuleInit, OnModuleDestroy {
        chatId,
        workspace.id,
      );
+      // #492: HYDRATE needy assistant rows from the steps table BEFORE the replay
+      // map. A #492 mid-run assistant row carries only a step marker
+      // (metadata.parts:[]); its real per-step parts live in `ai_chat_run_steps`.
+      // The graceful terminal callbacks (onFinish/onError/onAbort -> flushAssistant)
+      // assemble the full inline parts, so a normally-ended turn already has them.
+      // But a HARD crash mid-run (SIGKILL/OOM) fires NO terminal callback, so the
+      // row stays parts:[]; without this, rowToUiMessage falls back to an empty
+      // text part and the partial tool-calls/results/text — durable in the steps
+      // table — would DROP OUT of the model's replay context (regressing #183
+      // step-granular durability for the model consumer). Mirrors the controller's
+      // withReconstructedParts EXACTLY (same needy predicate + hydration helper).
+      // Guarded on the optional repo: absent (positional test builds) degrades to
+      // the current behavior rather than crashing.
+      let replayHistory = oldHistory;
+      if (this.aiChatRunStepRepo) {
+        const needy = oldHistory.filter(
+          (r) => r.role === 'assistant' && !rowHasInlineParts(r),
+        );
+        if (needy.length > 0) {
+          const stepsByMessage = await this.aiChatRunStepRepo.findByMessageIds(
+            needy.map((r) => r.id),
+            workspace.id,
+          );
+          replayHistory = hydrateAssistantParts(oldHistory, stepsByMessage);
+        }
+      }
      const uiMessages: Array<Omit<UIMessage, 'id'> & { id: string }> = [
-        ...oldHistory.map(rowToUiMessage),
+        ...replayHistory.map(rowToUiMessage),
        {
          id: 'pending-user',
          role: 'user',
@@ -1153,7 +1188,9 @@ export class AiChatService implements OnModuleInit, OnModuleDestroy {
      // hint — confirm it against the persisted history (the preceding assistant
      // turn must really be aborted/streaming) so a spoofed flag cannot inject the
      // interrupt note onto an ordinary turn. The partial output the model needs is
-      // already in `messages` (the aborted assistant row replays via findRecent).
+      // already in `messages`: a #492 mid-run row's per-step parts live only in the
+      // `ai_chat_run_steps` table and were hydrated into the replay history above,
+      // so the aborted assistant turn replays WITH its partial parts intact.
      // Append the new user turn (shape-only) so index -2 is the prior assistant.
      const interrupted = isInterruptResume(
        [...oldHistory, { role: 'user', status: null, metadata: null }],
@@ -1192,27 +1229,52 @@ export class AiChatService implements OnModuleInit, OnModuleDestroy {
      }
      // Last turn's provider-reported context size (authoritative when present).
      const priorContextTokens = lastAssistantContextTokens(oldHistory);
-      // Reactive recovery (#490): if the LAST turn was rejected for context
-      // overflow (stamped by onError), trim AGGRESSIVELY this turn — the
-      // overflowing turn produced no usage signal, so a normal-threshold trim may
-      // not shrink enough to fit. This is what un-bricks a chat that just 400'd.
-      const priorOverflowed = lastAssistantReplayOverflow(oldHistory);
+      // Reactive recovery (#490/#520): `k` = how many CONSECUTIVE preceding turns
+      // were rejected for context overflow (stamped by onError). Each consecutive
+      // overflow trims MORE aggressively (resolveEffectiveReplayThreshold scales the
+      // budget by 0.5**k, clamped at the floor) so recovery ESCALATES until the
+      // history fits — the overflowing turn produced no usage signal, so a single
+      // fixed cut may not shrink enough when the real model window is small. This is
+      // what un-bricks a chat that keeps 400'ing on the context window.
+      const priorOverflowCount = lastAssistantReplayOverflowCount(oldHistory);
      const effectiveThreshold = resolveEffectiveReplayThreshold(
        replayBudget.thresholdTokens,
-        priorOverflowed,
+        priorOverflowCount,
      );
-      if (priorOverflowed) {
-        this.logger.warn(
-          `AI chat (chat ${chatId}): previous turn hit context overflow; ` +
-            `applying aggressive replay budget (${effectiveThreshold} tokens).`,
-        );
+      // #520 Option B: recovery MAY cut the replay budget BELOW the admin-configured
+      // window when the provider keeps proving non-fit (the anti-brick invariant of
+      // the reactive branch beats a config that a 400 has disproved). Surface it so
+      // the admin sees their window is factually too large, and mark the turn so the
+      // UI/telemetry can show it. Only true when actually below (not on in-budget
+      // escalation edge cases); k>0 implies below for any budget >= 2 tokens.
+      const replayBelowConfiguredBudget =
+        replayBudget.thresholdTokens != null &&
+        effectiveThreshold != null &&
+        effectiveThreshold < replayBudget.thresholdTokens;
+      if (priorOverflowCount > 0) {
+        if (replayBelowConfiguredBudget) {
+          this.logger.warn(
+            `AI chat (chat ${chatId}): configured replay budget ` +
+              `(${replayBudget.thresholdTokens} tokens) does not fit the model — ` +
+              `replaying BELOW it at ${effectiveThreshold} tokens after ` +
+              `${priorOverflowCount} consecutive context overflow(s) ` +
+              `(escalation level ${priorOverflowCount}). Lower chatContextWindow ` +
+              `to match the model's real context window.`,
+          );
+        } else {
+          this.logger.warn(
+            `AI chat (chat ${chatId}): ${priorOverflowCount} consecutive context ` +
+              `overflow(s); applying escalated aggressive replay budget ` +
+              `(${effectiveThreshold} tokens).`,
+          );
+        }
      }
      const preTrim = trimHistoryForReplay(
        messages,
        effectiveThreshold,
        // A prior OVERFLOW means the provider count is stale/absent — force the
        // char-estimate path by ignoring priorContextTokens on recovery.
-        priorOverflowed ? undefined : priorContextTokens,
+        priorOverflowCount > 0 ? undefined : priorContextTokens,
      );
      messages = preTrim.messages;
      // Observability (#490): record the budgeter's decision on the turn so the UI
@@ -1410,10 +1472,11 @@ export class AiChatService implements OnModuleInit, OnModuleDestroy {
      const baseTools = { ...external.tools, ...docmostTools };

      // Deferred tool loading state (#332), scoped to THIS streaming loop:
-      //  - `activatedTools` is per-TURN mutable state — a fresh closure Set created
-      //    per streamText call, NOT module-global and NOT persisted, so a new turn
-      //    starts cold. loadTools.execute adds to it; prepareAgentStep reads it to
-      //    widen `activeTools` on the NEXT step.
+      //  - `activatedTools` is a fresh closure Set per streamText call (not
+      //    module-global), SEEDED from the chat's persisted metadata.activatedTools
+      //    (#490, just below) so activation carries across turns. loadTools.execute
+      //    adds to it; prepareAgentStep reads it to widen `activeTools` on the NEXT
+      //    step; turn end persists it back.
      //  - `validDeferredNames` = every tool that is NOT core (the in-app deferred
      //    tools + ALL external MCP tools), computed from the ACTUAL toolset so an
      //    external tool is loadable by its namespaced name. loadTools rejects any
@@ -1557,17 +1620,57 @@ export class AiChatService implements OnModuleInit, OnModuleDestroy {
        // connection when finalize runs, so the SQL `WHERE status='streaming'`
        // (not this flag) is what prevents it clobbering the terminal row.
        if (finalized) return null;
-        // Build the flush ONCE so the returned count is EXACTLY the persisted
-        // `stepsPersisted` (both derive from capturedSteps.length at this instant).
-        const flushed = flushAssistant(capturedSteps, '', 'streaming', {
-          pageChanged,
-          partsCache,
-        });
-        const stepsPersisted = flushed.metadata.stepsPersisted as number;
+        // The count derives from capturedSteps.length at THIS instant, so the
+        // returned value is EXACTLY the persisted `stepsPersisted` the ring rotates
+        // on (whether we take the append-persist path or the legacy fallback).
+        const stepsPersisted = capturedSteps.length;
        try {
-          await this.aiChatMessageRepo.update(assistantId, workspace.id, flushed, {
-            onlyIfStreaming: true,
-          });
+          if (this.aiChatRunStepRepo) {
+            // #492 APPEND-PERSIST: write only THIS finished step's parts to the
+            // steps table (O(step) WAL), then bump the row's CHEAP step marker —
+            // NO growing `metadata.parts` blob (that O(n²) full-row rewrite is
+            // exactly what this removes). The full `metadata.parts` is assembled
+            // once at finalize; a mid-run resume seed is reconstructed from the
+            // step rows (reconstructRunParts). The INSERT is idempotent
+            // (ON CONFLICT DO NOTHING), so a re-fired step never doubles the parts.
+            const index = stepsPersisted - 1;
+            if (index >= 0) {
+              const stepParts = assistantParts(
+                [capturedSteps[index]],
+                '',
+                partsCache,
+              );
+              await this.aiChatRunStepRepo.insertStep(
+                assistantId,
+                workspace.id,
+                index,
+                stepParts,
+              );
+            }
+            // Marker UPDATE: advance stepsPersisted + keep the toolTrace era marker
+            // (bumps updatedAt so the delta poll observes the step, and carries the
+            // frontier a resuming client attaches from). Scoped onlyIfStreaming so a
+            // late marker never clobbers the terminal finalize.
+            await this.aiChatMessageRepo.update(
+              assistantId,
+              workspace.id,
+              { metadata: stepMarkerMetadata(stepsPersisted) },
+              { onlyIfStreaming: true },
+            );
+          } else {
+            // Legacy fallback (no steps table wired — positional test builds): the
+            // pre-#492 full-row flush, so parts still land inline on the row.
+            const flushed = flushAssistant(capturedSteps, '', 'streaming', {
+              pageChanged,
+              partsCache,
+            });
+            await this.aiChatMessageRepo.update(
+              assistantId,
+              workspace.id,
+              flushed,
+              { onlyIfStreaming: true },
+            );
+          }
          return stepsPersisted;
        } catch (err) {
          this.logger.warn(
@@ -1826,6 +1929,10 @@ export class AiChatService implements OnModuleInit, OnModuleDestroy {
                pageChanged,
                partsCache,
                replayTrimmedToTokens,
+                // #520 Option B: mark the turn when recovery replayed BELOW the
+                // configured budget (only when it actually did).
+                replayBelowConfiguredBudget:
+                  replayBelowConfiguredBudget || undefined,
              }),
            );
            // #184/#487: the RUN is finalized ALWAYS (never gated on the message).
@@ -1904,7 +2011,16 @@ export class AiChatService implements OnModuleInit, OnModuleDestroy {
                pageChanged,
                partsCache,
                replayTrimmedToTokens,
-                replayOverflow: overflow || undefined,
+                // #520: escalate the consecutive-overflow counter so the NEXT turn
+                // trims MORE aggressively (0.5**k). k grows by 1 each consecutive
+                // overflow; a clean finalize omits the field, resetting it to 0.
+                replayOverflowCount: overflow
+                  ? priorOverflowCount + 1
+                  : undefined,
+                // #520 Option B: mark the turn when THIS replay was already below the
+                // configured budget (only when it actually was).
+                replayBelowConfiguredBudget:
+                  replayBelowConfiguredBudget || undefined,
              }),
            );
            // #184: settle the RUN as failed, carrying the provider/transport cause.
@@ -2336,22 +2452,39 @@ export function seedActivatedTools(
 }

 /**
- * Whether the most recent assistant turn was rejected for CONTEXT OVERFLOW
- * (#490): its row carries `metadata.replayOverflow` (stamped by the stream's
- * onError). The next turn's budgeter reads this to trim aggressively — the
- * reactive recovery. Only the LAST assistant turn matters (an older overflow was
- * already recovered), so we stop at the first assistant row scanning backwards.
+ * How many CONSECUTIVE recent turns were rejected for CONTEXT OVERFLOW (#490/#520):
+ * `k`, read from the most recent assistant row's `metadata.replayOverflowCount`
+ * (stamped by the stream's onError, incremented each consecutive overflow and reset
+ * to 0 on any clean finalize). The next turn's budgeter feeds this to
+ * {@link resolveEffectiveReplayThreshold} to trim with ESCALATING aggression — the
+ * reactive recovery. Only the LAST assistant turn matters (its count already carries
+ * the consecutive streak; an older overflow followed by a clean turn was recovered),
+ * so we stop at the first assistant row scanning backwards.
+ *
+ * BACK-COMPAT: a row written by the pre-#520 boolean stamp (`replayOverflow: true`,
+ * no count) is read as k=1 — the old single 0.5× behavior — so in-flight chats do
+ * not regress across the deploy.
 */
-export function lastAssistantReplayOverflow(
+export function lastAssistantReplayOverflowCount(
  history: ReadonlyArray<AiChatMessage>,
-): boolean {
+): number {
  for (let i = history.length - 1; i >= 0; i--) {
    const row = history[i];
    if (row.role !== 'assistant') continue;
-    const meta = (row.metadata ?? {}) as { replayOverflow?: unknown };
-    return meta.replayOverflow === true;
+    const meta = (row.metadata ?? {}) as {
+      replayOverflowCount?: unknown;
+      replayOverflow?: unknown;
+    };
+    if (typeof meta.replayOverflowCount === 'number') {
+      // Guard against a corrupt/negative persisted value.
+      return meta.replayOverflowCount > 0
+        ? Math.floor(meta.replayOverflowCount)
+        : 0;
+    }
+    // Back-compat: legacy boolean stamp -> one overflow (0.5× cut).
+    return meta.replayOverflow === true ? 1 : 0;
  }
-  return false;
+  return 0;
 }

 /** The last message with role 'user' from a useChat payload, if any. */
@@ -2747,6 +2880,122 @@ export function rowToUiMessage(row: AiChatMessage): Omit<UIMessage, 'id'> & {
  return { id: row.id, role, parts: parts as UIMessage['parts'] };
 }

+/**
+ * Cheap step-marker metadata for the #492 per-step UPDATE. Advances
+ * `stepsPersisted` (the resume attach frontier) and keeps the `toolTraceVersion`
+ * era marker, WITHOUT the growing `parts` blob (those live in the steps table
+ * now; the full `metadata.parts` is assembled once at finalize by flushAssistant).
+ * `parts: []` is kept for shape stability — it reads as an empty inline-parts row,
+ * which is exactly the discriminator that routes reconstruction to the steps table.
+ */
+export function stepMarkerMetadata(
+  stepsPersisted: number,
+): Record<string, unknown> {
+  return { parts: [], toolTraceVersion: 2, stepsPersisted };
+}
+
+/**
+ * Whether an assistant row already carries its full UI parts INLINE on the row
+ * (`metadata.parts`). TRUE for every FINISHED row — old-era rows AND #492 rows,
+ * whose full parts are assembled once at finalize — and for old-era streaming
+ * snapshots (the pre-#492 per-step full-row flush). FALSE for a #492 MID-RUN
+ * record, whose per-step parts live in the `ai_chat_run_steps` table. This is the
+ * era discriminator the reconstruct seam branches on — no schema flag needed.
+ */
+export function rowHasInlineParts(row: { metadata?: unknown }): boolean {
+  const meta = (row.metadata ?? {}) as { parts?: unknown };
+  return Array.isArray(meta.parts) && meta.parts.length > 0;
+}
+
+/**
+ * Concatenate persisted per-step parts (in `stepIndex` order) into the turn's UI
+ * parts (#492). Reproduces EXACTLY what flushAssistant → assistantParts would have
+ * written to `metadata.parts` for those finished steps, since each step row stored
+ * `assistantParts([step])` at persist time.
+ */
+export function assembleStepParts(
+  stepRows: ReadonlyArray<{ stepIndex: number; parts: unknown }>,
+): UIMessage['parts'] {
+  const parts: Array<Record<string, unknown>> = [];
+  for (const step of [...stepRows].sort((a, b) => a.stepIndex - b.stepIndex)) {
+    if (Array.isArray(step.parts)) {
+      parts.push(...(step.parts as Array<Record<string, unknown>>));
+    }
+  }
+  return parts as UIMessage['parts'];
+}
+
+/**
+ * reconstructRunParts (#492) — the single backend-switch seam. Given an assistant
+ * ROW and its persisted step rows, return the turn's UI `parts` + the persisted
+ * step count, reading from the ROW when it already carries inline parts (old-era
+ * records AND every finished record) and from the STEPS TABLE otherwise (a #492
+ * mid-run record). The higher-level consumers (attach seed, delta poll, export)
+ * route their row→parts through this / {@link hydrateAssistantParts}, so old and
+ * new records reconstruct identically WITHOUT the consumers branching on the era.
+ */
+export function reconstructRunParts(
+  row: { metadata?: unknown; content?: string | null },
+  stepRows: ReadonlyArray<{ stepIndex: number; parts: unknown }>,
+): { parts: UIMessage['parts']; stepsPersisted: number } {
+  if (rowHasInlineParts(row)) {
+    const meta = row.metadata as {
+      parts: UIMessage['parts'];
+      stepsPersisted?: number;
+    };
+    return {
+      parts: meta.parts,
+      stepsPersisted:
+        typeof meta.stepsPersisted === 'number'
+          ? meta.stepsPersisted
+          : stepRows.length,
+    };
+  }
+  if (stepRows.length > 0) {
+    return {
+      parts: assembleStepParts(stepRows),
+      stepsPersisted: stepRows.length,
+    };
+  }
+  // No inline parts and no step rows: an old-era seed / empty streaming row. Fall
+  // back to a single text part from `content` (mirrors rowToUiMessage).
+  return {
+    parts: textPart(row.content ?? '') as UIMessage['parts'],
+    stepsPersisted: 0,
+  };
+}
+
+/**
+ * Fill each assistant row's `metadata.parts` from its step rows when the row does
+ * not already carry them inline (a #492 mid-run record), so a consumer that reads
+ * `metadata.parts` off the RAW row (the client seed/poll, the Markdown export)
+ * sees the reconstructed parts with NO change to itself. Rows that already have
+ * inline parts (old-era + finished) and non-assistant rows pass through untouched.
+ * Pure: returns new row objects, never mutates the inputs.
+ */
+export function hydrateAssistantParts<
+  T extends { id: string; role?: string; metadata?: unknown },
+>(
+  rows: ReadonlyArray<T>,
+  stepsByMessage: Map<
+    string,
+    ReadonlyArray<{ stepIndex: number; parts: unknown }>
+  >,
+): T[] {
+  return rows.map((row) => {
+    if (row.role !== 'assistant' || rowHasInlineParts(row)) return row;
+    const steps = stepsByMessage.get(row.id);
+    if (!steps || steps.length === 0) return row;
+    return {
+      ...row,
+      metadata: {
+        ...((row.metadata ?? {}) as Record<string, unknown>),
+        parts: assembleStepParts(steps),
+      },
+    };
+  });
+}
+
 /**
 * The persisted-row patch shape produced by {@link flushAssistant}. It is the
 * SAME shape the assistant repo insert/update consume (content + toolCalls +
@@ -2891,9 +3140,16 @@ export function flushAssistant(
    // the (estimated) token size it trimmed to — the UI can show "replay truncated
    // at N tokens". Omitted when nothing was trimmed.
    replayTrimmedToTokens?: number;
-    // #490 reactive branch: set when the provider rejected this turn for context
-    // overflow. Stamped into metadata so the NEXT turn's budgeter trims aggressively.
-    replayOverflow?: boolean;
+    // #490/#520 reactive branch: the consecutive context-overflow count for THIS
+    // turn (prior streak + 1) when the provider rejected it for context overflow.
+    // Stamped into metadata so the NEXT turn's budgeter trims with escalating
+    // aggression (0.5**k). Omitted (undefined) on a clean turn, which resets k to 0.
+    replayOverflowCount?: number;
+    // #520 Option B observability: true when recovery replayed this turn's history
+    // BELOW the admin-configured budget (the configured window did not fit and the
+    // anti-brick invariant cut past it). Omitted on a normal in-budget replay so the
+    // flag marks ONLY the "config is factually too large" case.
+    replayBelowConfiguredBudget?: boolean;
  },
 ): AssistantFlush {
  const finished = capturedSteps ?? [];
@@ -2946,7 +3202,10 @@ export function flushAssistant(
    metadata.maxContextTokens = extra.maxContextTokens;
  if (extra?.replayTrimmedToTokens)
    metadata.replayTrimmedToTokens = extra.replayTrimmedToTokens;
-  if (extra?.replayOverflow) metadata.replayOverflow = true;
+  if (extra?.replayOverflowCount && extra.replayOverflowCount > 0)
+    metadata.replayOverflowCount = extra.replayOverflowCount;
+  if (extra?.replayBelowConfiguredBudget)
+    metadata.replayBelowConfiguredBudget = true;
  if (extra?.error) metadata.error = extra.error;
  // Persist the page-change diff the agent saw this turn (#274 observability),
  // so history / the Markdown export can show what the user changed. Only when
@@ -1,6 +1,11 @@
 import { randomBytes } from 'crypto';
 import { Client } from 'pg';
-import { flushAssistant, serializeSteps } from './ai-chat.service';
+import {
+  flushAssistant,
+  serializeSteps,
+  lastAssistantReplayOverflowCount,
+} from './ai-chat.service';
+import type { AiChatMessage } from '@docmost/db/types/entity.types';

 /**
 * #490 write-volume regression — an OBSERVABLE-PROPERTY test on a LIVE Postgres,
@@ -207,3 +212,111 @@ describe('#490 write-volume on a live Postgres (pg_current_wal_lsn delta)', () =
    expect(v2).toBeLessThan(v1 * 0.75);
  }, 120_000);
 });
+
+/**
+ * #520 reactive-recovery COUNTER lifecycle on a LIVE Postgres — proves the
+ * consecutive-overflow count survives a real jsonb metadata round-trip (the persist
+ * path), not just an in-memory object. flushAssistant BUILDS the row metadata, we
+ * WRITE it to a jsonb column, READ it back, then reconstruct the assistant row and
+ * run lastAssistantReplayOverflowCount over it — exactly the read the next turn does.
+ *
+ * The lifecycle proven end-to-end through pg:
+ *   - consecutive overflows INCREMENT k (1 -> 2 -> 3);
+ *   - a CLEAN finalize omits the field, which the reader treats as a RESET to 0;
+ *   - a legacy boolean row (`replayOverflow: true`) reads back as k=1 (back-compat).
+ */
+describe('#520 overflow-counter lifecycle on a live Postgres (jsonb round-trip)', () => {
+  let client: Client | undefined;
+  let available = false;
+
+  beforeAll(async () => {
+    try {
+      client = new Client(CONN);
+      await client.connect();
+      await client.query('SELECT 1');
+      available = true;
+    } catch {
+      available = false;
+      client = undefined;
+    }
+  });
+
+  afterAll(async () => {
+    await client?.end().catch(() => undefined);
+  });
+
+  // Round-trip an arbitrary metadata object through a real jsonb column and read it
+  // back as the reconstructed assistant row the next turn would load.
+  async function roundTrip(
+    c: Client,
+    metadata: unknown,
+  ): Promise<AiChatMessage> {
+    await c.query('UPDATE _wal_counter SET metadata=$1 WHERE id=1', [
+      JSON.stringify(metadata),
+    ]);
+    const back = (await c.query('SELECT metadata FROM _wal_counter WHERE id=1'))
+      .rows[0].metadata as Record<string, unknown>;
+    return { role: 'assistant', metadata: back } as unknown as AiChatMessage;
+  }
+
+  it('increments across consecutive overflows, resets on a clean turn, and honors the legacy boolean', async () => {
+    if (!available || !client) {
+      console.warn('SKIP: gitmost-test-pg not reachable; skipping counter test.');
+      return;
+    }
+    const c = client;
+    await c.query('DROP TABLE IF EXISTS _wal_counter');
+    await c.query('CREATE TABLE _wal_counter(id int primary key, metadata jsonb)');
+    await c.query("INSERT INTO _wal_counter VALUES (1, '{}'::jsonb)");
+
+    // Turn 1 overflow: prior streak 0 -> stamp k=1 (as the service does: prior+1).
+    let prior = lastAssistantReplayOverflowCount([]); // fresh chat
+    expect(prior).toBe(0);
+    let row = await roundTrip(
+      c,
+      flushAssistant([], '', 'error', {
+        error: 'ctx',
+        replayOverflowCount: prior + 1,
+      }).metadata,
+    );
+    prior = lastAssistantReplayOverflowCount([row]);
+    expect(prior).toBe(1);
+
+    // Turn 2 overflow: prior 1 -> stamp k=2.
+    row = await roundTrip(
+      c,
+      flushAssistant([], '', 'error', {
+        error: 'ctx',
+        replayOverflowCount: prior + 1,
+      }).metadata,
+    );
+    prior = lastAssistantReplayOverflowCount([row]);
+    expect(prior).toBe(2);
+
+    // Turn 3 overflow: prior 2 -> stamp k=3.
+    row = await roundTrip(
+      c,
+      flushAssistant([], '', 'error', {
+        error: 'ctx',
+        replayOverflowCount: prior + 1,
+      }).metadata,
+    );
+    prior = lastAssistantReplayOverflowCount([row]);
+    expect(prior).toBe(3);
+
+    // Turn 4 CLEAN finalize: no overflow -> the field is omitted -> reset to 0.
+    row = await roundTrip(
+      c,
+      flushAssistant([], 'all good', 'completed', { finishReason: 'stop' })
+        .metadata,
+    );
+    expect('replayOverflowCount' in (row.metadata as object)).toBe(false);
+    expect(lastAssistantReplayOverflowCount([row])).toBe(0);
+
+    // Back-compat: a row persisted by the pre-#520 boolean stamp reads back as k=1.
+    row = await roundTrip(c, { replayOverflow: true });
+    expect(lastAssistantReplayOverflowCount([row])).toBe(1);
+
+    await c.query('DROP TABLE IF EXISTS _wal_counter');
+  }, 60_000);
+});
@@ -1,14 +1,146 @@
 import type { ModelMessage } from 'ai';
 import {
  resolveReplayBudget,
+  resolveEffectiveReplayThreshold,
  isContextOverflowError,
  estimateMessagesTokens,
  trimHistoryForReplay,
  REPLAY_BUDGET_DEFAULT_TOKENS,
+  REPLAY_BUDGET_WINDOW_FRACTION,
+  REPLAY_MIN_FLOOR_TOKENS,
  REPLAY_TRUNCATION_MARKER,
  REPLAY_TURN_COLLAPSED_MARKER,
 } from './history-budget';

+describe('resolveEffectiveReplayThreshold (#520 iterative escalation)', () => {
+  // The escalation table: each consecutive overflow (k) deepens the cut by 0.5×.
+  it('scales the base by 0.5**k, flooring (not rounding) fractional tokens', () => {
+    const base = 100_000;
+    expect(resolveEffectiveReplayThreshold(base, 0)).toBe(base); // k=0: unchanged
+    expect(resolveEffectiveReplayThreshold(base, 1)).toBe(50_000); // 0.5×
+    expect(resolveEffectiveReplayThreshold(base, 2)).toBe(25_000); // 0.25×
+    expect(resolveEffectiveReplayThreshold(base, 3)).toBe(12_500); // 0.125×
+    // Floors, not rounds.
+    expect(resolveEffectiveReplayThreshold(99_999, 1)).toBe(49_999);
+  });
+
+  it('passes a null base (trimming OFF) through unchanged for any k', () => {
+    for (const k of [0, 1, 2, 5, 100]) {
+      expect(resolveEffectiveReplayThreshold(null, k)).toBeNull();
+    }
+  });
+
+  // The crux of #520: convergence. A large k is clamped at REPLAY_MIN_FLOOR_TOKENS,
+  // so the escalation CONVERGES to a small-but-usable budget instead of trimming to
+  // zero — and, unlike the old fixed 0.5× that stuck at 50k, it drops far enough to
+  // fit a small real model window.
+  it('clamps a large k at the floor (converges, never below)', () => {
+    const base = 100_000;
+    for (const k of [4, 6, 10, 50, 200]) {
+      const t = resolveEffectiveReplayThreshold(base, k) as number;
+      expect(t).toBe(REPLAY_MIN_FLOOR_TOKENS);
+      expect(t).toBeGreaterThanOrEqual(REPLAY_MIN_FLOOR_TOKENS);
+    }
+  });
+
+  // Residual-brick regression (#520): flat-default base 100k, real window ~40k. The
+  // OLD fixed single 0.5× stuck at 50k > 40k forever (re-overflows every turn — the
+  // brick). The iterative cut drops BELOW 40k after a couple more consecutive
+  // overflows, so the history finally fits and the chat un-bricks.
+  it('un-bricks: escalation drops below a small real window the fixed 0.5× never could', () => {
+    const base = 100_000;
+    const realWindow = 40_000;
+    // The old terminal state: 0.5× = 50k, still above the window.
+    expect(resolveEffectiveReplayThreshold(base, 1)).toBeGreaterThan(realWindow);
+    // Escalation converges under the window.
+    const converged = [2, 3, 4, 5].some(
+      (k) => (resolveEffectiveReplayThreshold(base, k) as number) < realWindow,
+    );
+    expect(converged).toBe(true);
+    // MUTATION SENTINEL: reverting `** k` to `** 1` (fixed 0.5×) makes every k yield
+    // 50k, so `converged` above would be FALSE and this test reddens. Removing the
+    // floor reddens the clamp test instead.
+  });
+
+  // "Don't INFLATE above itself" is still an invariant: the floor never RAISES a
+  // legitimately small configured budget above itself (that would re-overflow the
+  // very window it was set for). Under #520 Option B the floor is min(FLOOR,
+  // floor(0.5×base)), so for a base BELOW the floor recovery MAY cut it further —
+  // down to floor(0.5×base), i.e. AT LEAST the old single 0.5× cut — but never above.
+  it('never inflates a small configured budget above itself (may cut below it, #520 Option B)', () => {
+    const small = 5_000; // below REPLAY_MIN_FLOOR_TOKENS
+    const floor = Math.min(REPLAY_MIN_FLOOR_TOKENS, Math.floor(small * 0.5)); // 2500
+    expect(resolveEffectiveReplayThreshold(small, 0)).toBe(small); // k=0 unchanged
+    for (const k of [1, 2, 3, 10]) {
+      const t = resolveEffectiveReplayThreshold(small, k) as number;
+      // Invariant: never RAISED above the configured budget.
+      expect(t).toBeLessThanOrEqual(small);
+      // Option B: never trimmed below the absolute floor (converges).
+      expect(t).toBeGreaterThanOrEqual(floor);
+    }
+    // The old single 0.5× cut is reached (and pinned) — recovery is never WORSE than
+    // before, and DOES cut below the configured budget on overflow (Option B). Under
+    // the old floor==budget behavior this would be `small` (5000), not `floor`.
+    expect(resolveEffectiveReplayThreshold(small, 1)).toBe(floor);
+  });
+
+  // #520 Option B: with a configured window (NOT the flat default), repeated overflow
+  // escalates the replay budget BELOW the configured budget, down to the absolute
+  // floor — the chat must not brick even when the configured window is too large for
+  // the model. A CLEAN turn (k back to 0) restores the full configured budget.
+  it('escalates below the configured budget down to the floor, and resets on a clean turn', () => {
+    // Configured context window 8000 -> budget = floor(0.7 × 8000) = 5600 (the code's
+    // window->budget ratio; compute it, do not hardcode).
+    const window = 8_000;
+    const budget = resolveReplayBudget(window).thresholdTokens as number;
+    expect(budget).toBe(Math.floor(REPLAY_BUDGET_WINDOW_FRACTION * window)); // 5600
+
+    // The absolute floor for this budget = min(FLOOR, floor(0.5 × budget)) = 2800
+    // (a "small window": 0.5×budget < REPLAY_MIN_FLOOR_TOKENS), which is BELOW the
+    // 5600 configured budget.
+    const floor = Math.min(
+      REPLAY_MIN_FLOOR_TOKENS,
+      Math.floor(budget * 0.5),
+    ); // 2800
+    expect(floor).toBe(2_800);
+    expect(floor).toBeLessThan(budget); // below the configured budget
+
+    // k=0 -> full configured budget (no overflow yet).
+    expect(resolveEffectiveReplayThreshold(budget, 0)).toBe(budget);
+    // k=1 -> cut BELOW the configured budget to the 0.5× floor (2800). This is the
+    // MUTATION SENTINEL: with the OLD floor==configured-budget behavior this would be
+    // max(2800, 5600) = 5600 (never below budget), so the assertion reddens.
+    expect(resolveEffectiveReplayThreshold(budget, 1)).toBe(floor);
+    expect(resolveEffectiveReplayThreshold(budget, 1)).toBeLessThan(budget);
+    // k>=2 stays at the floor (converges, never below it).
+    for (const k of [2, 3, 5, 20]) {
+      expect(resolveEffectiveReplayThreshold(budget, k)).toBe(floor);
+    }
+
+    // A CLEAN turn resets k to 0 -> the full configured budget is restored (recovery
+    // is not sticky; it only bites while the provider keeps proving non-fit).
+    expect(resolveEffectiveReplayThreshold(budget, 0)).toBe(budget);
+  });
+
+  // #520 Option B, LARGE window: a big configured budget escalates in DISTINCT steps
+  // below itself, converging to the fixed absolute floor REPLAY_MIN_FLOOR_TOKENS.
+  it('a large configured budget escalates below itself down to REPLAY_MIN_FLOOR_TOKENS', () => {
+    const budget = resolveReplayBudget(200_000).thresholdTokens as number; // 140000
+    // The floor for a large window is the fixed REPLAY_MIN_FLOOR_TOKENS (8k), well
+    // BELOW the configured budget.
+    expect(
+      Math.min(REPLAY_MIN_FLOOR_TOKENS, Math.floor(budget * 0.5)),
+    ).toBe(REPLAY_MIN_FLOOR_TOKENS);
+    const seq = [0, 1, 2, 3, 4, 5, 6].map(
+      (k) => resolveEffectiveReplayThreshold(budget, k) as number,
+    );
+    expect(seq).toEqual([140_000, 70_000, 35_000, 17_500, 8_750, 8_000, 8_000]);
+    // Every escalated step (k>=1) is below the configured budget; convergence floor.
+    for (const t of seq.slice(1)) expect(t).toBeLessThan(budget);
+    expect(seq[seq.length - 1]).toBe(REPLAY_MIN_FLOOR_TOKENS);
+  });
+});
+
 describe('resolveReplayBudget', () => {
  it('uses floor(0.7 x window) for a configured window (no cap)', () => {
    // 0.7 x 60k = 42k
@@ -22,10 +22,35 @@ export const REPLAY_BUDGET_DEFAULT_TOKENS = 100_000;
 /** Fraction of a configured context window used as the budget. */
 export const REPLAY_BUDGET_WINDOW_FRACTION = 0.7;
 /**
- * Fraction of the normal budget used for the REACTIVE re-trim after a provider
- * context-overflow 400 — the preventive estimate under-counted, so cut harder.
+ * Per-step fraction of the normal budget applied on the REACTIVE re-trim after a
+ * provider context-overflow 400 — the preventive estimate under-counted, so cut
+ * harder. This is now applied ITERATIVELY: with `k` consecutive overflow turns the
+ * budget is scaled by `fraction ** k` (k=1 -> 0.5×, k=2 -> 0.25×, …), so recovery
+ * ESCALATES turn over turn until the replayed history finally fits, instead of the
+ * old single fixed 0.5× cut that could never un-brick a chat whose real model
+ * window is smaller than 0.5 × the (unconfigured, flat-default) base budget (#520).
 */
 export const REPLAY_AGGRESSIVE_FRACTION = 0.5;
+/**
+ * Absolute lower bound (tokens) on the escalating reactive budget: the iterative
+ * cut is clamped here so it CONVERGES (a fixed floor, not an ever-shrinking value
+ * that would eventually trim everything). Rationale: below ~8k tokens a chat cannot
+ * carry meaningful recent context, and even a small real model window comfortably
+ * fits this much — keep-recent-turns still applies on top, so a handful of recent
+ * turns survive.
+ *
+ * #520 Option B: for a LARGE configured window this floor sits BELOW the configured
+ * replay budget, and recovery is allowed to escalate PAST the configured budget down
+ * to it — "the chat must not brick on overflow" is an INVARIANT of the reactive
+ * branch, and a configured window is a claim about model capacity, not a promise
+ * about replay size; once the provider proves non-fit with a 400, reality beats the
+ * config. This does NOT change the NORMAL path's upper bound (#510 Option A still
+ * respects the configured budget while it fits) — it is survival once non-fit is
+ * proven. For a SMALL configured window the effective floor is instead the old
+ * single 0.5× cut (never worse than before, and never RAISED above the budget); see
+ * {@link resolveEffectiveReplayThreshold}.
+ */
+export const REPLAY_MIN_FLOOR_TOKENS = 8_000;
 /**
 * Turns (a user message + its assistant/tool replies) kept FULL at the tail,
 * including the current one — never trimmed. Older turns are compacted first.
@@ -85,22 +110,48 @@ export function resolveReplayBudget(rawContextWindow: unknown): ReplayBudget {
 }

 /**
- * The effective replay threshold for THIS turn, given the base budget and whether
- * the PREVIOUS turn hit a context-overflow 400 (the reactive-recovery signal,
- * `metadata.replayOverflow`). On recovery the base budget is scaled down by
- * {@link REPLAY_AGGRESSIVE_FRACTION}: the overflowing turn produced no usage
- * signal, so the preventive estimate under-counted and a normal-threshold trim may
- * not shrink enough to fit — this harder cut is what un-bricks the chat.
+ * The effective replay threshold for THIS turn, given the base budget and `k` — the
+ * number of CONSECUTIVE preceding turns that hit a context-overflow 400 (the
+ * reactive-recovery signal `metadata.replayOverflowCount`, read from the last
+ * assistant row). On recovery the base budget is scaled down ITERATIVELY by
+ * {@link REPLAY_AGGRESSIVE_FRACTION} ** k and clamped at {@link REPLAY_MIN_FLOOR_TOKENS}:
+ *   - k=0 -> base unchanged (no overflow: nothing to recover from).
+ *   - k=1 -> floor(0.5 × base); k=2 -> floor(0.25 × base); … each further consecutive
+ *     overflow tightens the cut, so recovery ESCALATES until the history fits.
+ *   - the escalation is clamped at the floor so it CONVERGES — this is what un-bricks
+ *     a chat whose real model window is smaller than a single 0.5× cut of the base
+ *     (e.g. an unconfigured window: flat-default base 100k, real window <50k) (#520).
+ *
+ * The overflowing turn produced no usage signal, so the preventive estimate
+ * under-counted and a normal-threshold (or single fixed 0.5×) trim may not shrink
+ * enough to fit; the escalating cut is what recovers such a chat.
 *
 * A `null` base budget (trimming OFF) is passed through unchanged: an explicit
 * off-switch is never overridden by the recovery path.
+ *
+ * The absolute floor is `min(REPLAY_MIN_FLOOR_TOKENS, floor(0.5 × base))` (#520
+ * Option B):
+ *   - LARGE window (floor(0.5 × base) >= REPLAY_MIN_FLOOR_TOKENS) -> the fixed
+ *     REPLAY_MIN_FLOOR_TOKENS, which is BELOW the configured budget: escalation is
+ *     ALLOWED to cut past the configured budget down to this absolute minimum, so a
+ *     chat whose real model window is far smaller than the configured window still
+ *     un-bricks (the invariant beats a config reality disproved with a 400).
+ *   - SMALL window (floor(0.5 × base) < REPLAY_MIN_FLOOR_TOKENS) -> floor(0.5 ×
+ *     base), i.e. AT LEAST the old single 0.5× cut: recovery is never WORSE than the
+ *     pre-#520 behavior, and the floor is still never RAISED above the configured
+ *     budget itself (that would re-overflow the very window it was set for).
 */
 export function resolveEffectiveReplayThreshold(
  thresholdTokens: number | null,
-  priorOverflowed: boolean,
+  k: number,
 ): number | null {
-  if (!priorOverflowed || thresholdTokens == null) return thresholdTokens;
-  return Math.floor(thresholdTokens * REPLAY_AGGRESSIVE_FRACTION);
+  if (thresholdTokens == null || k <= 0) return thresholdTokens;
+  const scaled = Math.floor(thresholdTokens * REPLAY_AGGRESSIVE_FRACTION ** k);
+  const floor = Math.min(
+    REPLAY_MIN_FLOOR_TOKENS,
+    Math.floor(thresholdTokens * REPLAY_AGGRESSIVE_FRACTION),
+  );
+  return Math.max(scaled, floor);
 }

 /**
@@ -210,6 +210,55 @@ describe('PublicShareChatToolsService.forShare', () => {
    });
  });

+  describe('getSharePage under approved publication (owner decision: assistant sees the frozen saved version)', () => {
+    it('reads the FROZEN saved content/title returned by the boundary, not a live re-fetch', async () => {
+      // #370 Stage B owner decision: ALL public reads — including the share
+      // assistant's page-read tool — see the published saved version, so a
+      // visitor and the assistant see the same bytes. The content swap lives in
+      // resolveReadableSharePage (the single canonical boundary), so the tool
+      // simply consumes the frozen { page } it returns: the assistant must never
+      // re-read the live draft behind the boundary's back.
+      const frozenContent = {
+        type: 'doc',
+        content: [
+          {
+            type: 'paragraph',
+            content: [{ type: 'text', text: 'FROZEN saved version body' }],
+          },
+        ],
+      };
+      // The boundary already swapped content+title to the manual version while
+      // preserving the live id (its unit test pins that); the tool sees this.
+      const frozenPage = {
+        id: 'page-1',
+        title: 'Saved Version Title',
+        deletedAt: null,
+        content: frozenContent,
+      };
+
+      const { svc, shareService } = makeService({
+        resolveReadableSharePage: jest
+          .fn()
+          .mockResolvedValue({ share: { id: 'SHARE-A' }, page: frozenPage }),
+      });
+      // updatePublicAttachments sanitizes the FROZEN page it was handed.
+      shareService.updatePublicAttachments.mockResolvedValue(frozenContent);
+
+      const tools = svc.forShare('SHARE-A', 'ws-1');
+      const out = (await (tools.getSharePage as unknown as ToolExec).execute({
+        pageId: 'page-1',
+      })) as { title: string; markdown: string };
+
+      // Sanitizer is handed the frozen page (never a separate live fetch).
+      expect(shareService.updatePublicAttachments).toHaveBeenCalledWith(
+        frozenPage,
+      );
+      // Title + body come from the saved (frozen) version.
+      expect(out.title).toBe('Saved Version Title');
+      expect(out.markdown).toContain('FROZEN saved version body');
+    });
+  });
+
  describe('getSharePage non-resolving page (deleted / restricted / out-of-share)', () => {
    it('resolveReadableSharePage returns null (e.g. soft-deleted page) => generic error, NO content sanitized/returned', async () => {
      // The canonical boundary 404s a soft-deleted / restricted / out-of-tree
@@ -10,6 +10,12 @@ import { Transform } from 'class-transformer';

 export type ContentFormat = 'json' | 'markdown' | 'html';

+// READ-only rendering formats for `getPage` (#502). A superset of the writable
+// `ContentFormat` with `text` — a flat, deterministic, machine-diffable text
+// rendering — added. Kept SEPARATE from `ContentFormat` so the write path
+// (createPage/updatePage `parseProsemirrorContent`) can never be handed `text`.
+export type PageReadFormat = ContentFormat | 'text';
+
 export class CreatePageDto {
  @IsOptional()
  @IsString()
@@ -5,10 +5,11 @@ import {
  IsOptional,
  IsString,
  IsUUID,
+  MaxLength,
 } from 'class-validator';
 import { Transform } from 'class-transformer';

-import { ContentFormat } from './create-page.dto';
+import { PageReadFormat } from './create-page.dto';
 import { IsPageIdOrSlugId } from './page-identity.validator';

 export class PageIdDto {
@@ -43,8 +44,19 @@ export class PageInfoDto extends PageIdDto {

  @IsOptional()
  @Transform(({ value }) => value?.toLowerCase())
-  @IsIn(['json', 'markdown', 'html'])
-  format?: ContentFormat;
+  @IsIn(['json', 'markdown', 'html', 'text'])
+  format?: PageReadFormat;
+}
+
+export class PageWorkTimeDto extends PageIdDto {
+  // Viewer IANA timezone for the per-day punch-card buckets (§6.3). Optional —
+  // falls back to UTC server-side. Length-capped so a bogus value cannot bloat
+  // the request; the value is only ever handed to Intl.DateTimeFormat, which
+  // throws on an unknown zone (caught by the controller → 400).
+  @IsOptional()
+  @IsString()
+  @MaxLength(64)
+  tz?: string;
 }

 export class DeletePageDto extends PageIdDto {
@@ -0,0 +1,76 @@
+import { NotFoundException } from '@nestjs/common';
+import { PageController } from './page.controller';
+import { jsonToText, jsonToMarkdown } from '../../collaboration/collaboration.util';
+
+// #502 READ: getPage `format:"text"` routes through the deterministic jsonToText
+// path (placeholders for non-text nodes, block-per-line), while `format:"json"`
+// (or none) returns the raw content and `format:"markdown"` still converts. This
+// pins the CONTROLLER wiring with lightweight mocks (no DB needed — the jsonToText
+// output contract itself is pinned in json-to-text-deterministic.spec.ts).
+
+const CONTENT = {
+  type: 'doc',
+  content: [
+    { type: 'heading', attrs: { level: 1 }, content: [{ type: 'text', text: 'Config' }] },
+    {
+      type: 'paragraph',
+      content: [
+        { type: 'text', text: 'key=', marks: [{ type: 'bold' }] },
+        { type: 'text', text: 'value' },
+      ],
+    },
+    { type: 'image', attrs: { src: 's' } },
+  ],
+};
+
+function makeController(page: any): PageController {
+  const pageRepo = { findById: jest.fn().mockResolvedValue(page) } as any;
+  const pageAccessService = {
+    validateCanViewWithPermissions: jest
+      .fn()
+      .mockResolvedValue({ canEdit: true, hasRestriction: false }),
+  } as any;
+  // Only pageRepo + pageAccessService are exercised by getPage; the rest are
+  // never touched on this path, so undefined placeholders are fine.
+  return new PageController(
+    undefined as any, // pageService
+    pageRepo,
+    undefined as any, // pageHistoryService
+    undefined as any, // spaceAbility
+    pageAccessService,
+    undefined as any, // backlinkService
+    undefined as any, // labelService
+    undefined as any, // auditService
+  );
+}
+
+const user = { id: 'u1' } as any;
+
+describe('PageController.getPage — format:"text" (#502)', () => {
+  it('returns deterministic flat text with placeholders for non-text nodes', async () => {
+    const controller = makeController({ id: 'p1', content: CONTENT });
+    const res: any = await controller.getPage({ pageId: 'p1', format: 'text' } as any, user);
+    expect(res.content).toBe(jsonToText(CONTENT, { deterministic: true }));
+    expect(res.content).toBe('Config\nkey=value\n[image]');
+    expect(res.permissions).toEqual({ canEdit: true, hasRestriction: false });
+  });
+
+  it('markdown format still converts to markdown (unchanged)', async () => {
+    const controller = makeController({ id: 'p1', content: CONTENT });
+    const res: any = await controller.getPage({ pageId: 'p1', format: 'markdown' } as any, user);
+    expect(res.content).toBe(jsonToMarkdown(CONTENT));
+  });
+
+  it('json / no format returns the raw ProseMirror content object', async () => {
+    const controller = makeController({ id: 'p1', content: CONTENT });
+    const res: any = await controller.getPage({ pageId: 'p1' } as any, user);
+    expect(res.content).toEqual(CONTENT); // untouched object, not a string
+  });
+
+  it('missing page -> NotFoundException', async () => {
+    const controller = makeController(null);
+    await expect(
+      controller.getPage({ pageId: 'nope', format: 'text' } as any, user),
+    ).rejects.toBeInstanceOf(NotFoundException);
+  });
+});
@@ -1,3 +1,8 @@
+import {
+  BadRequestException,
+  ForbiddenException,
+  NotFoundException,
+} from '@nestjs/common';
 import { PageController } from './page.controller';

 // Direct instantiation with stub deps. The Test.createTestingModule form failed
@@ -22,4 +27,88 @@ describe('PageController', () => {
  it('should be defined', () => {
    expect(controller).toBeDefined();
  });
+
+  // #395 — the work-time endpoint must be gated exactly like /history.
+  describe('getPageWorkTime', () => {
+    const user = { id: 'u1' } as any;
+
+    function build(overrides: {
+      page?: any;
+      validate?: jest.Mock;
+      compute?: jest.Mock;
+    }) {
+      const pageRepo = { findById: jest.fn().mockResolvedValue(overrides.page) };
+      const pageAccessService = {
+        validateCanView: overrides.validate ?? jest.fn().mockResolvedValue(undefined),
+      };
+      const pageHistoryService = {
+        computeWorkTime:
+          overrides.compute ?? jest.fn().mockResolvedValue({ workMs: 0 }),
+      };
+      const c = new PageController(
+        {} as any,
+        pageRepo as any,
+        pageHistoryService as any,
+        {} as any,
+        pageAccessService as any,
+        {} as any,
+        {} as any,
+        {} as any,
+      );
+      return { c, pageRepo, pageAccessService, pageHistoryService };
+    }
+
+    it('404s when the page does not exist', async () => {
+      const { c } = build({ page: null });
+      await expect(
+        c.getPageWorkTime({ pageId: 'p1' } as any, user),
+      ).rejects.toBeInstanceOf(NotFoundException);
+    });
+
+    it('enforces validateCanView before computing, then delegates with tz', async () => {
+      const validate = jest.fn().mockResolvedValue(undefined);
+      const compute = jest.fn().mockResolvedValue({ workMs: 42 });
+      const { c } = build({ page: { id: 'pg' }, validate, compute });
+      const out = await c.getPageWorkTime(
+        { pageId: 'pg', tz: 'Europe/Moscow' } as any,
+        user,
+      );
+      expect(validate).toHaveBeenCalledWith({ id: 'pg' }, user);
+      expect(compute).toHaveBeenCalledWith('pg', 'Europe/Moscow');
+      expect(out).toEqual({ workMs: 42 });
+    });
+
+    it('propagates a denied view gate and does NOT reach compute (security)', async () => {
+      // If validateCanView is moved AFTER computeWorkTime, the timeline of a page
+      // the caller may not see would be read/estimated before the gate — this
+      // locks the order: a rejecting gate must short-circuit before any compute.
+      const validate = jest.fn().mockRejectedValue(new ForbiddenException());
+      const compute = jest.fn().mockResolvedValue({ workMs: 1 });
+      const { c, pageHistoryService } = build({
+        page: { id: 'pg' },
+        validate,
+        compute,
+      });
+      await expect(
+        c.getPageWorkTime({ pageId: 'pg' } as any, user),
+      ).rejects.toBeInstanceOf(ForbiddenException);
+      expect(pageHistoryService.computeWorkTime).not.toHaveBeenCalled();
+    });
+
+    it('maps an unknown-timezone RangeError to a 400', async () => {
+      const compute = jest.fn().mockRejectedValue(new RangeError('bad tz'));
+      const { c } = build({ page: { id: 'pg' }, compute });
+      await expect(
+        c.getPageWorkTime({ pageId: 'pg', tz: 'X/Y' } as any, user),
+      ).rejects.toBeInstanceOf(BadRequestException);
+    });
+
+    it('does not swallow a non-RangeError from the service', async () => {
+      const compute = jest.fn().mockRejectedValue(new Error('db down'));
+      const { c } = build({ page: { id: 'pg' }, compute });
+      await expect(
+        c.getPageWorkTime({ pageId: 'pg' } as any, user),
+      ).rejects.toThrow('db down');
+    });
+  });
 });
@@ -21,6 +21,7 @@ import {
  PageHistoryIdDto,
  PageIdDto,
  PageInfoDto,
+  PageWorkTimeDto,
 } from './dto/page.dto';
 import { PageHistoryService } from './services/page-history.service';
 import { AuthUser } from '../../common/decorators/auth-user.decorator';
@@ -49,6 +50,7 @@ import { AddLabelsDto, RemoveLabelDto } from '../label/dto/label.dto';
 import {
  jsonToHtml,
  jsonToMarkdown,
+  jsonToText,
 } from '../../collaboration/collaboration.util';
 import { AuditEvent, AuditResource } from '../../common/events/audit-events';
 import {
@@ -93,10 +95,16 @@ export class PageController {
    const permissions = { canEdit, hasRestriction };

    if (dto.format && dto.format !== 'json' && page.content) {
-      const contentOutput =
-        dto.format === 'markdown'
-          ? jsonToMarkdown(page.content)
-          : jsonToHtml(page.content);
+      let contentOutput: string;
+      if (dto.format === 'markdown') {
+        contentOutput = jsonToMarkdown(page.content);
+      } else if (dto.format === 'text') {
+        // #502: flat, deterministic, machine-diffable text (block-per-line,
+        // inline marks/anchors dropped, non-text nodes -> stable placeholders).
+        contentOutput = jsonToText(page.content, { deterministic: true });
+      } else {
+        contentOutput = jsonToHtml(page.content);
+      }
      return {
        ...page,
        content: contentOutput,
@@ -524,6 +532,32 @@ export class PageController {
    return this.pageHistoryService.findHistoryByPageId(page.id, pagination);
  }

+  @HttpCode(HttpStatus.OK)
+  @Post('/history/time')
+  async getPageWorkTime(
+    @Body() dto: PageWorkTimeDto,
+    @AuthUser() user: User,
+  ) {
+    const page = await this.pageRepo.findById(dto.pageId);
+    if (!page) {
+      throw new NotFoundException('Page not found');
+    }
+
+    // Same view gate as /history and /history/info.
+    await this.pageAccessService.validateCanView(page, user);
+
+    try {
+      return await this.pageHistoryService.computeWorkTime(page.id, dto.tz);
+    } catch (e) {
+      // Intl.DateTimeFormat throws RangeError on an unknown IANA zone; surface
+      // it as a 400 rather than a 500.
+      if (e instanceof RangeError) {
+        throw new BadRequestException('Invalid timezone');
+      }
+      throw e;
+    }
+  }
+
  @HttpCode(HttpStatus.OK)
  @Post('/history/info')
  async getPageHistoryInfo(
@@ -818,6 +852,11 @@ export class PageController {
      throw new NotFoundException('Page not found');
    }

+    // Target-only validateCanView is intentional: getPageBreadCrumbs returns
+    // the full ancestor chain WITHOUT per-ancestor permission filtering. Safe
+    // because page restrictions inherit down the tree, so any ancestor the
+    // caller could not view would already hide the target here — see the
+    // getPageBreadCrumbs docstring / #471.
    await this.pageAccessService.validateCanView(page, user);

    return this.pageService.getPageBreadCrumbs(page.id);
@@ -3,6 +3,23 @@ import { PageHistoryRepo } from '@docmost/db/repos/page/page-history.repo';
 import { PageHistory } from '@docmost/db/types/entity.types';
 import { PaginationOptions } from '@docmost/db/pagination/pagination-options';
 import { CursorPaginationResult } from '@docmost/db/pagination/cursor-pagination';
+import {
+  computeWorkTime,
+  bucketByDay,
+  DEFAULT_WORK_TIME_CONFIG,
+  WorkTimeConfig,
+  PerDay,
+} from '../work-time';
+
+export interface PageWorkTime {
+  workMs: number;
+  agentOnlyMs: number;
+  perDay: PerDay[];
+  /** the config actually used, so the UI can show "≈" + the T_gap threshold. */
+  config: WorkTimeConfig;
+  /** the tz the per-day buckets were computed in (echoed back for the label). */
+  tz: string;
+}

@Injectable()
 export class PageHistoryService {
@@ -23,4 +40,33 @@ export class PageHistoryService {
      paginationOptions,
    );
  }
+
+  /**
+   * #395 — estimate time worked on a page (§5) and bucket it into the viewer's
+   * calendar days for the punch-card (§6.3). Reads only the cheap history
+   * projection (no `content`); the estimate itself is a pure, deterministic
+   * function so it is unit-tested exhaustively without a DB.
+   *
+   * `tz` is the viewer's IANA zone (browser locale) — it moves which day a
+   * session lands in and where its windows sit, but never the total (§10).
+   */
+  async computeWorkTime(
+    pageId: string,
+    tz = 'UTC',
+    config?: Partial<WorkTimeConfig>,
+  ): Promise<PageWorkTime> {
+    const rows = await this.pageHistoryRepo.findTimelineByPageId(pageId);
+    const result = computeWorkTime(rows, config);
+    const usedConfig: WorkTimeConfig = { ...DEFAULT_WORK_TIME_CONFIG, ...config };
+    // `bucketByDay` consumes the pure core's un-bucketed sessions here; the
+    // full session list is NOT shipped on the response (no client reads it).
+    const perDay = bucketByDay(result.sessions, tz);
+    return {
+      workMs: result.workMs,
+      agentOnlyMs: result.agentOnlyMs,
+      perDay,
+      config: usedConfig,
+      tz,
+    };
+  }
 }
@@ -1071,6 +1071,29 @@ export class PageService {
    });
  }

+  /**
+   * Walk the ancestor chain of `childPageId` up to the space root, filtered
+   * ONLY by `deletedAt` (+ MAX_PAGE_TREE_DEPTH) — WITHOUT per-ancestor
+   * permission filtering. Callers that expose this to a user (the
+   * `/breadcrumbs` endpoint) validate `validateCanView` on the TARGET page
+   * only, then return the whole chain of ancestor titles (#471).
+   *
+   * This is safe — NOT a title leak — because page restrictions inherit DOWN
+   * the tree: to view a page the caller must hold permission on EVERY
+   * restricted ancestor (`validateCanView` -> `canUserAccessPage` checks the
+   * full ancestor chain — see page-access.service.ts / page-permission.repo.ts
+   * `canUserEditPage`). A restricted ancestor the caller may not see would
+   * therefore already hide the TARGET page itself, so every ancestor reachable
+   * here is one the caller is already entitled to view (content stays gated
+   * regardless — getPage/getNode re-check permissions).
+   *
+   * Note the guarantee is the narrow "may view a descendant => may view its
+   * ancestors", NOT "space membership sees every page" — restricted subtrees do
+   * hide pages from members. Per-ancestor permission filtering here was
+   * considered and declined as redundant given the inheritance invariant above
+   * (#471). The same chain feeds the web-UI breadcrumb bar under identical CASL
+   * scope.
+   */
  async getPageBreadCrumbs(childPageId: string, trx?: KyselyTransaction) {
    const ancestors = await dbOrTx(this.db, trx)
      .withRecursive('page_ancestors', (db) =>
@@ -0,0 +1,129 @@
+import { bucketByDay, zonedDayStart } from './bucket-by-day';
+import { computeWorkTime } from './compute-work-time';
+import { WorkSession, TimelineSample } from './work-time.types';
+
+const MIN = 60 * 1000;
+const HOUR = 60 * MIN;
+
+function work(start: number, end: number): WorkSession {
+  return { start, end, class: 'work' };
+}
+function agent(start: number, end: number): WorkSession {
+  return { start, end, class: 'agent_only' };
+}
+
+function sumActive(perDay: ReturnType<typeof bucketByDay>): number {
+  return perDay.reduce((a, d) => a + d.activeMs, 0);
+}
+
+describe('bucketByDay', () => {
+  it('Σ activeMs == workMs — the §6.3 consistency invariant', () => {
+    const rows: TimelineSample[] = [
+      { createdAt: '2026-07-04T03:40:00Z', lastUpdatedById: 'h', lastUpdatedSource: 'user', lastUpdatedAiChatId: null, kind: null },
+      { createdAt: '2026-07-04T03:49:00Z', lastUpdatedById: 'h', lastUpdatedSource: 'user', lastUpdatedAiChatId: null, kind: null },
+      { createdAt: '2026-07-04T18:11:00Z', lastUpdatedById: 'h', lastUpdatedSource: 'user', lastUpdatedAiChatId: null, kind: null },
+      { createdAt: '2026-07-06T15:34:00Z', lastUpdatedById: 'h', lastUpdatedSource: 'user', lastUpdatedAiChatId: null, kind: null },
+    ];
+    const r = computeWorkTime(rows);
+    const perDay = bucketByDay(r.sessions, 'UTC');
+    expect(sumActive(perDay)).toBe(r.workMs);
+  });
+
+  it('empty input → no days', () => {
+    expect(bucketByDay([], 'UTC')).toEqual([]);
+  });
+
+  it('midnight-crossing session splits across two days, sum preserved (§9#9)', () => {
+    const start = Date.UTC(2026, 0, 10, 23, 14);
+    const end = Date.UTC(2026, 0, 11, 0, 40);
+    const perDay = bucketByDay([work(start, end)], 'UTC');
+    expect(perDay).toHaveLength(2);
+    expect(perDay[0].dayISO).toBe('2026-01-10');
+    expect(perDay[1].dayISO).toBe('2026-01-11');
+    expect(perDay[0].activeMs).toBe(46 * MIN); // 23:14 → 24:00
+    expect(perDay[1].activeMs).toBe(40 * MIN); // 00:00 → 00:40
+    expect(sumActive(perDay)).toBe(end - start);
+  });
+
+  it('empty days between active days are emitted, not skipped (§9#12)', () => {
+    const d1 = work(Date.UTC(2026, 0, 10, 10, 0), Date.UTC(2026, 0, 10, 11, 0));
+    const d3 = work(Date.UTC(2026, 0, 12, 10, 0), Date.UTC(2026, 0, 12, 11, 0));
+    const perDay = bucketByDay([d1, d3], 'UTC');
+    expect(perDay.map((d) => d.dayISO)).toEqual([
+      '2026-01-10',
+      '2026-01-11',
+      '2026-01-12',
+    ]);
+    expect(perDay[1].activeMs).toBe(0);
+    expect(perDay[1].windows).toEqual([]);
+  });
+
+  it('agent_only windows are drawn but excluded from activeMs', () => {
+    const w = work(Date.UTC(2026, 0, 10, 9, 0), Date.UTC(2026, 0, 10, 10, 0));
+    const a = agent(Date.UTC(2026, 0, 10, 14, 0), Date.UTC(2026, 0, 10, 14, 30));
+    const perDay = bucketByDay([w, a], 'UTC');
+    expect(perDay).toHaveLength(1);
+    expect(perDay[0].activeMs).toBe(1 * HOUR);
+    expect(perDay[0].agentMs).toBe(30 * MIN);
+    expect(perDay[0].windows.map((x) => x.class)).toEqual(['work', 'agent_only']);
+  });
+
+  it('work and agent_only are unioned SEPARATELY (agent does not swallow work)', () => {
+    // Overlapping work + agent windows on the same day.
+    const w = work(Date.UTC(2026, 0, 10, 9, 0), Date.UTC(2026, 0, 10, 11, 0));
+    const a = agent(Date.UTC(2026, 0, 10, 10, 0), Date.UTC(2026, 0, 10, 12, 0));
+    const perDay = bucketByDay([w, a], 'UTC');
+    expect(perDay[0].activeMs).toBe(2 * HOUR);
+    expect(perDay[0].agentMs).toBe(2 * HOUR);
+  });
+
+  it('overlapping same-class sessions are UNIONed, not summed (no double-count)', () => {
+    // Two work sessions that overlap 10:00–10:30 on one day.
+    const a = work(Date.UTC(2026, 0, 10, 9, 0), Date.UTC(2026, 0, 10, 10, 30));
+    const b = work(Date.UTC(2026, 0, 10, 10, 0), Date.UTC(2026, 0, 10, 11, 0));
+    const perDay = bucketByDay([a, b], 'UTC');
+    expect(perDay).toHaveLength(1);
+    // Union 09:00–11:00 = 2h, NOT 90m + 60m = 150m.
+    expect(perDay[0].activeMs).toBe(2 * HOUR);
+    // The drawn windows are also merged to one, so the punch-card cannot render
+    // an overlapping double bar.
+    expect(perDay[0].windows).toHaveLength(1);
+    expect(perDay[0].windows[0].start).toBe(a.start);
+    expect(perDay[0].windows[0].end).toBe(b.end);
+  });
+
+  it('DST fall-back: a full 25-hour day still balances (§9#14)', () => {
+    // America/New_York ends DST 2026-11-01 (25h day).
+    const tz = 'America/New_York';
+    const dayStart = zonedDayStart(Date.UTC(2026, 10, 1, 12, 0), tz);
+    const nextStart = zonedDayStart(dayStart + 26 * HOUR, tz);
+    expect(nextStart - dayStart).toBe(25 * HOUR);
+    const perDay = bucketByDay([work(dayStart, nextStart)], tz);
+    expect(perDay).toHaveLength(1);
+    expect(perDay[0].dayISO).toBe('2026-11-01');
+    expect(perDay[0].activeMs).toBe(25 * HOUR);
+    expect(sumActive(perDay)).toBe(nextStart - dayStart);
+  });
+
+  it('DST spring-forward: a full 23-hour day still balances (§9#14)', () => {
+    // America/New_York starts DST 2026-03-08 (23h day).
+    const tz = 'America/New_York';
+    const dayStart = zonedDayStart(Date.UTC(2026, 2, 8, 12, 0), tz);
+    const nextStart = zonedDayStart(dayStart + 26 * HOUR, tz);
+    expect(nextStart - dayStart).toBe(23 * HOUR);
+    const perDay = bucketByDay([work(dayStart, nextStart)], tz);
+    expect(perDay).toHaveLength(1);
+    expect(perDay[0].activeMs).toBe(23 * HOUR);
+    expect(sumActive(perDay)).toBe(nextStart - dayStart);
+  });
+
+  it('tz changes the day a session lands in but not the total', () => {
+    const start = Date.UTC(2026, 0, 10, 2, 0); // 02:00 UTC
+    const end = Date.UTC(2026, 0, 10, 3, 0);
+    const utc = bucketByDay([work(start, end)], 'UTC');
+    const ny = bucketByDay([work(start, end)], 'America/New_York'); // 21:00 prev day
+    expect(utc[0].dayISO).toBe('2026-01-10');
+    expect(ny[0].dayISO).toBe('2026-01-09');
+    expect(sumActive(utc)).toBe(sumActive(ny));
+  });
+});
@@ -0,0 +1,180 @@
+import { WorkSession, PerDay, DayWindow } from './work-time.types';
+
+/**
+ * Merge intervals into a disjoint, sorted union. Overlapping OR touching
+ * intervals are joined. Empty input → [].
+ */
+function union(intervals: Array<[number, number]>): Array<[number, number]> {
+  if (intervals.length === 0) return [];
+  const sorted = [...intervals].sort((a, b) => a[0] - b[0]);
+  const out: Array<[number, number]> = [];
+  let [curStart, curEnd] = sorted[0];
+  for (let i = 1; i < sorted.length; i++) {
+    const [s, e] = sorted[i];
+    if (s <= curEnd) {
+      if (e > curEnd) curEnd = e;
+    } else {
+      out.push([curStart, curEnd]);
+      curStart = s;
+      curEnd = e;
+    }
+  }
+  out.push([curStart, curEnd]);
+  return out;
+}
+
+// Cache one Intl formatter per tz — constructing them is comparatively costly.
+const fmtCache = new Map<string, Intl.DateTimeFormat>();
+
+function partsFmt(tz: string): Intl.DateTimeFormat {
+  let fmt = fmtCache.get(tz);
+  if (!fmt) {
+    fmt = new Intl.DateTimeFormat('en-US', {
+      timeZone: tz,
+      year: 'numeric',
+      month: '2-digit',
+      day: '2-digit',
+      hour: '2-digit',
+      minute: '2-digit',
+      second: '2-digit',
+      hour12: false,
+    });
+    fmtCache.set(tz, fmt);
+  }
+  return fmt;
+}
+
+interface WallParts {
+  year: number;
+  month: number;
+  day: number;
+  hour: number;
+  minute: number;
+  second: number;
+}
+
+/** Wall-clock parts of an instant in `tz` (DST-correct, via Intl). */
+function wallParts(ms: number, tz: string): WallParts {
+  const parts = partsFmt(tz).formatToParts(new Date(ms));
+  const get = (type: string) =>
+    Number(parts.find((p) => p.type === type)?.value ?? '0');
+  let hour = get('hour');
+  // Intl emits "24" for midnight under some engines/locales; normalize to 0.
+  if (hour === 24) hour = 0;
+  return {
+    year: get('year'),
+    month: get('month'),
+    day: get('day'),
+    hour,
+    minute: get('minute'),
+    second: get('second'),
+  };
+}
+
+/** tz offset (wall − real) at an instant, in ms. */
+function offset(ms: number, tz: string): number {
+  const p = wallParts(ms, tz);
+  const asUTC = Date.UTC(p.year, p.month - 1, p.day, p.hour, p.minute, p.second);
+  return asUTC - ms;
+}
+
+/**
+ * Epoch-ms of the local-midnight day start of `ms` in `tz`. DST-correct: takes
+ * the calendar day of the instant, its wall-midnight, then converts back with
+ * the offset that actually applies AT that midnight (refined once). The rare
+ * tz-with-a-DST-transition-exactly-at-midnight case is a documented edge (§9#14).
+ */
+export function zonedDayStart(ms: number, tz: string): number {
+  const p = wallParts(ms, tz);
+  const wallMidnightAsUTC = Date.UTC(p.year, p.month - 1, p.day, 0, 0, 0);
+  let start = wallMidnightAsUTC - offset(ms, tz);
+  // Refine with the offset at the computed midnight (DST may differ from `ms`).
+  start = wallMidnightAsUTC - offset(start, tz);
+  return start;
+}
+
+/** The next local midnight after `dayStart` (handles 23/25h DST days). */
+function nextDayStart(dayStart: number, tz: string): number {
+  // +26h always lands inside the NEXT calendar day (day length ∈ [23h,25h]),
+  // never two days ahead; startOf('day') of it is the next midnight.
+  return zonedDayStart(dayStart + 26 * 60 * 60 * 1000, tz);
+}
+
+function isoDay(dayStart: number, tz: string): string {
+  const p = wallParts(dayStart, tz);
+  const pad = (n: number) => String(n).padStart(2, '0');
+  return `${p.year}-${pad(p.month)}-${pad(p.day)}`;
+}
+
+/** Clip a union to [lo, hi) and emit windows of `class`. */
+function clip(
+  merged: Array<[number, number]>,
+  lo: number,
+  hi: number,
+  cls: DayWindow['class'],
+): DayWindow[] {
+  const out: DayWindow[] = [];
+  for (const [s, e] of merged) {
+    const start = Math.max(s, lo);
+    const end = Math.min(e, hi);
+    if (end > start) out.push({ start, end, class: cls });
+  }
+  return out;
+}
+
+/**
+ * #395 §6.3 — bucket sessions into calendar days of `tz` for the punch-card.
+ * Pure and deterministic. `work` and `agent_only` are unioned SEPARATELY (else
+ * agent windows would swallow work windows on overlap), then each union is split
+ * at tz midnight boundaries (`startOf('day')` in tz, NOT "+24h" — DST-safe §9#14)
+ * and clipped to each day.
+ *
+ * By construction Σ perDay.activeMs == workMs: the days are a partition of the
+ * `work` union — no loss, no dup, even on 23/25h DST days. `agent_only` windows
+ * are drawn but NOT in activeMs. Empty days between the first and last active day
+ * are emitted (empty track + "—") so the rhythm/pauses stay visible.
+ */
+export function bucketByDay(sessions: WorkSession[], tz: string): PerDay[] {
+  const uWork = union(
+    sessions.filter((s) => s.class === 'work').map((s) => [s.start, s.end]),
+  );
+  const uAgent = union(
+    sessions
+      .filter((s) => s.class === 'agent_only')
+      .map((s) => [s.start, s.end]),
+  );
+
+  if (uWork.length === 0 && uAgent.length === 0) return [];
+
+  const minStart = Math.min(
+    uWork.length ? uWork[0][0] : Infinity,
+    uAgent.length ? uAgent[0][0] : Infinity,
+  );
+  const maxEnd = Math.max(
+    uWork.length ? uWork[uWork.length - 1][1] : -Infinity,
+    uAgent.length ? uAgent[uAgent.length - 1][1] : -Infinity,
+  );
+
+  const perDay: PerDay[] = [];
+  let dayStart = zonedDayStart(minStart, tz);
+  // Guard against a pathological non-advancing boundary.
+  let guard = 0;
+  while (dayStart < maxEnd && guard < 100000) {
+    guard++;
+    const dayEnd = nextDayStart(dayStart, tz);
+    const workWin = clip(uWork, dayStart, dayEnd, 'work');
+    const agentWin = clip(uAgent, dayStart, dayEnd, 'agent_only');
+    const activeMs = workWin.reduce((a, w) => a + (w.end - w.start), 0);
+    const agentMs = agentWin.reduce((a, w) => a + (w.end - w.start), 0);
+    const windows = [...workWin, ...agentWin].sort((a, b) => a.start - b.start);
+    perDay.push({
+      day: dayStart,
+      dayISO: isoDay(dayStart, tz),
+      activeMs,
+      agentMs,
+      windows,
+    });
+    dayStart = dayEnd;
+  }
+  return perDay;
+}
@@ -0,0 +1,358 @@
+import { computeWorkTime } from './compute-work-time';
+import { bucketByDay } from './bucket-by-day';
+import { TimelineSample, WorkSession } from './work-time.types';
+
+const MIN = 60 * 1000;
+
+/** Union wall-clock of a set of intervals (touching intervals merge). */
+function unionMs(intervals: Array<[number, number]>): number {
+  if (intervals.length === 0) return 0;
+  const sorted = [...intervals].sort((a, b) => a[0] - b[0]);
+  let total = 0;
+  let [cs, ce] = sorted[0];
+  for (let i = 1; i < sorted.length; i++) {
+    const [s, e] = sorted[i];
+    if (s <= ce) {
+      if (e > ce) ce = e;
+    } else {
+      total += ce - cs;
+      cs = s;
+      ce = e;
+    }
+  }
+  return total + (ce - cs);
+}
+
+const ivsOf = (sessions: WorkSession[], cls?: string): Array<[number, number]> =>
+  sessions
+    .filter((x) => cls == null || x.class === cls)
+    .map((x) => [x.start, x.end] as [number, number]);
+
+function s(
+  iso: string,
+  opts: {
+    source?: string | null;
+    chat?: string | null;
+    kind?: string | null;
+    by?: string | null;
+  } = {},
+): TimelineSample {
+  return {
+    createdAt: `${iso}Z`,
+    lastUpdatedById: opts.by ?? 'human-1',
+    lastUpdatedSource: opts.source === undefined ? 'user' : opts.source,
+    lastUpdatedAiChatId: opts.chat ?? null,
+    kind: opts.kind ?? null,
+  };
+}
+
+// §7 config: T_gap=30m, P_in+P_out=10m, P_single=2m.
+const S7 = { tGap: 30 * MIN, agentTGap: 30 * MIN, pIn: 5 * MIN, pOut: 5 * MIN, pSingle: 2 * MIN };
+
+describe('computeWorkTime', () => {
+  it('§7 fixture — sessionizes 20-ish samples to ≈1h32m, not the ≈60h naive span', () => {
+    const rows: TimelineSample[] = [
+      // S1: multi-sample morning session
+      s('2026-07-04T03:40:00'),
+      s('2026-07-04T03:45:00'),
+      s('2026-07-04T03:49:00'),
+      // S2: agent burst (one run) then human supervising → class work
+      s('2026-07-04T15:43:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T15:47:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T15:50:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T16:13:00'),
+      // S3: single
+      s('2026-07-04T18:11:00'),
+      // S4: multi-sample evening session
+      s('2026-07-04T19:38:00'),
+      s('2026-07-04T19:44:00'),
+      s('2026-07-04T19:54:00'),
+      // S5 / S6: two singles two days later, 44m apart → two sessions at T_gap=30
+      s('2026-07-06T15:34:00'),
+      s('2026-07-06T16:18:00'),
+    ];
+
+    const r = computeWorkTime(rows, S7);
+
+    // 19 + 40 + 2 + 26 + 2 + 2 = 91 minutes.
+    expect(r.workMs).toBe(91 * MIN);
+    expect(r.agentOnlyMs).toBe(0);
+    expect(r.sessions).toHaveLength(6);
+    expect(r.sessions.every((x) => x.class === 'work')).toBe(true);
+
+    const naiveSpan =
+      new Date('2026-07-06T16:18:00Z').getTime() -
+      new Date('2026-07-04T03:40:00Z').getTime();
+    expect(naiveSpan).toBeGreaterThan(60 * 60 * MIN); // ≈60h
+    expect(r.workMs).toBeLessThan(naiveSpan / 30); // dramatically smaller
+  });
+
+  it('n=0 → zero, no sessions', () => {
+    const r = computeWorkTime([]);
+    expect(r).toEqual({ workMs: 0, agentOnlyMs: 0, sessions: [] });
+  });
+
+  it('n=1 human → one P_single work session', () => {
+    const r = computeWorkTime([s('2026-07-04T10:00:00')], S7);
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('work');
+    expect(r.workMs).toBe(2 * MIN);
+    expect(r.agentOnlyMs).toBe(0);
+    // pre-roll only: [t − P_single, t]
+    expect(r.sessions[0].end).toBe(new Date('2026-07-04T10:00:00Z').getTime());
+  });
+
+  it('n=1 agent → one P_single agent_only session, work=0 (§9#2)', () => {
+    const r = computeWorkTime(
+      [s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' })],
+      S7,
+    );
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('agent_only');
+    expect(r.workMs).toBe(0);
+    expect(r.agentOnlyMs).toBe(2 * MIN);
+  });
+
+  it('MUST close the last session — the newest session is not lost (§9#1)', () => {
+    // Two singles a day apart: without the post-loop close, the 2nd is dropped.
+    const rows = [s('2026-07-04T10:00:00'), s('2026-07-05T10:00:00')];
+    const r = computeWorkTime(rows, S7);
+    expect(r.sessions).toHaveLength(2);
+    const lastStart = Math.max(...r.sessions.map((x) => x.start));
+    expect(lastStart).toBe(
+      new Date('2026-07-05T10:00:00Z').getTime() - 2 * MIN,
+    );
+    expect(r.workMs).toBe(4 * MIN);
+  });
+
+  it('agent-burst collapse: density does not inflate — length = wall-clock', () => {
+    const span = ['00', '01', '02', '03', '04', '05', '06'];
+    const dense: TimelineSample[] = span.map((sec) =>
+      s(`2026-07-04T10:00:${sec}`, { source: 'agent', chat: 'c1', kind: 'agent' }),
+    );
+    const sparse: TimelineSample[] = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:00:06', { source: 'agent', chat: 'c1', kind: 'agent' }),
+    ];
+    const rDense = computeWorkTime(dense, S7);
+    const rSparse = computeWorkTime(sparse, S7);
+    // Same 6-second wall-clock span → same estimate regardless of snapshot count.
+    expect(rDense.agentOnlyMs).toBe(rSparse.agentOnlyMs);
+    expect(rDense.sessions).toHaveLength(1);
+    expect(rDense.sessions[0].class).toBe('agent_only');
+  });
+
+  it('supervisory agent time inside a human session counts as work, not agent', () => {
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:05:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:12:00'), // human within T_gap
+    ];
+    const r = computeWorkTime(rows, S7);
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('work');
+    expect(r.agentOnlyMs).toBe(0);
+    expect(r.workMs).toBeGreaterThan(0);
+  });
+
+  it('a DIFFERENT aiChatId breaks the burst — two agent runs, idle gap excluded', () => {
+    // Run c1 ends 10:05, run c2 starts 10:20 (15m > agentTGap 7m) → two sessions.
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:05:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:20:00', { source: 'agent', chat: 'c2', kind: 'agent' }),
+      s('2026-07-04T10:25:00', { source: 'agent', chat: 'c2', kind: 'agent' }),
+    ];
+    const r = computeWorkTime(rows); // default agentTGap = 7m
+    expect(r.sessions).toHaveLength(2);
+    expect(r.sessions.every((x) => x.class === 'agent_only')).toBe(true);
+    // The 15m idle gap between the two runs is NOT counted.
+    const run1 = 5 * MIN + 5 * MIN + 5 * MIN; // pIn + span + pOut
+    expect(r.agentOnlyMs).toBe(2 * run1);
+  });
+
+  it('idle pulse (same/null run) is a full activity sample that continues a burst', () => {
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      // idle flush 4m later, null run id → continues the burst, not a new one
+      s('2026-07-04T10:04:00', { source: 'agent', chat: null, kind: 'idle' }),
+      s('2026-07-04T10:08:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+    ];
+    const r = computeWorkTime(rows);
+    expect(r.sessions).toHaveLength(1);
+    // burst span 10:00→10:08 (+pIn/pOut) = 8 + 10 = 18m
+    expect(r.agentOnlyMs).toBe(18 * MIN);
+  });
+
+  it('a USER-sourced idle breaks an agent burst → session is work, not agent_only', () => {
+    // A human supervision idle inherits source=user (aiChatId:null) and must NOT
+    // be swallowed into the agent burst. Δ=3m is within the default agentTGap so
+    // the two samples stay one session — but its class flips to `work`.
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'agent', chat: 'c1', kind: 'agent' }),
+      s('2026-07-04T10:03:00', { source: 'user', chat: null, kind: 'idle' }),
+    ];
+    const r = computeWorkTime(rows);
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('work');
+    expect(r.workMs).toBeGreaterThan(0);
+    // The human idle is NOT captured as agent_only time.
+    expect(r.agentOnlyMs).toBe(0);
+    // Σ over `work` sessions == workMs and Σ over `agent_only` == agentOnlyMs.
+    const sum = (cls: string) =>
+      r.sessions
+        .filter((x) => x.class === cls)
+        .reduce((acc, x) => acc + (x.end - x.start), 0);
+    expect(sum('work')).toBe(r.workMs);
+    expect(sum('agent_only')).toBe(r.agentOnlyMs);
+  });
+
+  it('idle pulse keeps a human writing session visible (not excluded)', () => {
+    const rows = [
+      s('2026-07-04T10:00:00'),
+      s('2026-07-04T10:08:00', { kind: 'idle' }), // pulse within T_gap
+      s('2026-07-04T10:15:00'),
+    ];
+    const r = computeWorkTime(rows);
+    expect(r.sessions).toHaveLength(1);
+    expect(r.sessions[0].class).toBe('work');
+    // span 10:00→10:15 + pIn/pOut = 15 + 10 = 25m
+    expect(r.workMs).toBe(25 * MIN);
+  });
+
+  it('git-source samples are excluded (§10 excludeGit)', () => {
+    const rows = [
+      s('2026-07-04T10:00:00', { source: 'git', kind: 'boundary' }),
+      s('2026-07-04T10:01:00', { source: 'git', kind: 'boundary' }),
+    ];
+    expect(computeWorkTime(rows).workMs).toBe(0);
+    // ...but honoured off:
+    expect(
+      computeWorkTime(rows, { excludeGit: false }).workMs,
+    ).toBeGreaterThan(0);
+  });
+
+  it('rejects an invalid config (tGap < pIn + pOut)', () => {
+    expect(() =>
+      computeWorkTime([s('2026-07-04T10:00:00')], {
+        tGap: 5 * MIN,
+        pIn: 5 * MIN,
+        pOut: 5 * MIN,
+      }),
+    ).toThrow(/tGap/);
+  });
+
+  it('rejects an invalid config (2·agentTGap < pIn + pOut)', () => {
+    // tGap (default 15m) still ≥ pIn+pOut, so only the 2·agentTGap guard trips.
+    // Without it a short session of one class between two of the other could
+    // produce a NON-adjacent cross-class overlap the adjacent-only clip misses.
+    expect(() =>
+      computeWorkTime([s('2026-07-04T10:00:00')], {
+        agentTGap: 2 * MIN,
+        pIn: 5 * MIN,
+        pOut: 5 * MIN,
+      }),
+    ).toThrow(/agentTGap/);
+  });
+
+  // F1 — cross-class double-count. On the DEFAULT config agentTGap (7m) < pIn+pOut
+  // (10m), so a `work` session ending in an agent segment and a nearby separate
+  // `agent_only` run (gap in (7m,10m]) used to produce OVERLAPPING padded
+  // intervals — the same wall-clock counted into BOTH workMs and agentOnlyMs. The
+  // cross-class padding clip must make the two per-class unions disjoint.
+  it('does NOT double-count wall-clock across work/agent_only (§F1)', () => {
+    // user@0s ; agent(chatX)@60s (breaks into a work session with the human) ;
+    // agent(chatY)@560s,590s (a separate agent_only run). Raw gap between the work
+    // session (ends 60s) and the agent run (starts 560s) is 500s ∈ (agentTGap,
+    // pIn+pOut] once padded — the classic overlap window.
+    const rows: TimelineSample[] = [
+      s('2026-07-04T00:00:00'), // user @ 0s
+      s('2026-07-04T00:01:00', { source: 'agent', chat: 'cX', kind: 'agent' }), // @ 60s
+      s('2026-07-04T00:09:20', { source: 'agent', chat: 'cY', kind: 'agent' }), // @ 560s
+      s('2026-07-04T00:09:50', { source: 'agent', chat: 'cY', kind: 'agent' }), // @ 590s
+    ];
+    const r = computeWorkTime(rows); // DEFAULT config
+
+    // Both classes present.
+    expect(r.workMs).toBeGreaterThan(0);
+    expect(r.agentOnlyMs).toBeGreaterThan(0);
+
+    // Per-class metrics are exactly their own union (union, not Σ).
+    expect(r.workMs).toBe(unionMs(ivsOf(r.sessions, 'work')));
+    expect(r.agentOnlyMs).toBe(unionMs(ivsOf(r.sessions, 'agent_only')));
+
+    // The F1 invariant: work-union and agent-union are cross-class-disjoint, so
+    // the union of ALL padded intervals equals workMs + agentOnlyMs (no overlap).
+    // With the clip disabled this fails (union < sum by the 100s overlap).
+    expect(unionMs(ivsOf(r.sessions))).toBe(r.workMs + r.agentOnlyMs);
+  });
+
+  // F1 property/fuzz — random timelines across several timezones must uphold the
+  // work-time invariants. Backs the (corrected) PR claim of a real fuzz test.
+  it('property: random timelines uphold union & cross-class-disjoint invariants', () => {
+    // Deterministic LCG (numerical-recipes constants) so a failure is reproducible.
+    let seed = 0x9e3779b9 >>> 0;
+    const rand = () => {
+      seed = (Math.imul(seed, 1664525) + 1013904223) >>> 0;
+      return seed / 0x100000000;
+    };
+    const pick = <T>(arr: T[]): T => arr[Math.floor(rand() * arr.length)];
+
+    const tzs = [
+      'UTC',
+      'America/New_York',
+      'Europe/Moscow',
+      'Australia/Lord_Howe', // 30-min DST offset — a nasty bucket stress
+    ];
+    const base = Date.UTC(2026, 5, 1, 0, 0, 0); // 2026-06-01Z
+    const chats = ['c1', 'c2', 'c3'];
+
+    for (let iter = 0; iter < 250; iter++) {
+      const tz = pick(tzs);
+      const n = 2 + Math.floor(rand() * 18); // 2..19 rows
+      const rows: TimelineSample[] = [];
+      // Walk time forward by a random inter-sample gap. The gap distribution is
+      // centred on the DANGEROUS band — a bit under to a bit over pIn+pOut (10m)
+      // AND straddling agentTGap (7m) — so adjacent samples routinely split into
+      // separate sessions whose ±P padding would overlap if a class boundary sits
+      // there. Mixing user/agent classes at these gaps reliably manufactures the
+      // work-ending-in-agent → agent_only cross-class boundary F1 is about, plus
+      // dense within-class runs (occasional 0–2m gaps) that exercise the union.
+      let t = base + Math.floor(rand() * 60 * MIN);
+      for (let i = 0; i < n; i++) {
+        const roll = rand();
+        const gap =
+          roll < 0.25
+            ? Math.floor(rand() * 2 * MIN) // dense burst (same-class union)
+            : roll < 0.85
+              ? 5 * MIN + Math.floor(rand() * 8 * MIN) // 5–13m: the split band
+              : 20 * MIN + Math.floor(rand() * 40 * MIN); // long idle → new day-ish
+        t += gap;
+        const iso = new Date(t).toISOString().slice(0, 19); // 'YYYY-MM-DDTHH:MM:SS'
+        const isAgent = rand() < 0.5;
+        rows.push(
+          isAgent
+            ? s(iso, { source: 'agent', chat: pick(chats), kind: 'agent' })
+            : s(iso, { source: 'user', kind: rand() < 0.3 ? 'idle' : 'manual' }),
+        );
+      }
+
+      const r = computeWorkTime(rows); // DEFAULT config
+
+      const workIvs = ivsOf(r.sessions, 'work');
+      const agentIvs = ivsOf(r.sessions, 'agent_only');
+
+      // (1) each metric is exactly its per-class union (catches a union→Σ regress).
+      expect(r.workMs).toBe(unionMs(workIvs));
+      expect(r.agentOnlyMs).toBe(unionMs(agentIvs));
+
+      // (2) NO cross-class overlap: union(all) == workMs + agentOnlyMs (F1).
+      expect(unionMs(ivsOf(r.sessions))).toBe(r.workMs + r.agentOnlyMs);
+
+      // (3) bucket invariant: Σ per-day activeMs == workMs (§6.3).
+      const perDay = bucketByDay(r.sessions, tz);
+      const sumActive = perDay.reduce((a, d) => a + d.activeMs, 0);
+      expect(sumActive).toBe(r.workMs);
+    }
+  });
+});
@@ -0,0 +1,274 @@
+import {
+  TimelineSample,
+  WorkSession,
+  WorkTimeResult,
+} from './work-time.types';
+import { WorkTimeConfig, resolveWorkTimeConfig } from './work-time.config';
+
+/** A normalized activity sample (one history row), createdAt as epoch-ms. */
+interface NormSample {
+  t: number;
+  isAgent: boolean;
+  aiChatId: string | null;
+  kind: string | null;
+}
+
+/**
+ * A collapsed segment: either a scalar sample (t_start == t_end) or an
+ * agent-burst spanning several agent samples of one run (§5.1). It participates
+ * in sessionization as a single "sample".
+ */
+interface Segment {
+  tStart: number;
+  tEnd: number;
+  isAgent: boolean;
+}
+
+function toMs(v: Date | string | number): number {
+  if (v instanceof Date) return v.getTime();
+  if (typeof v === 'number') return v;
+  return new Date(v).getTime();
+}
+
+/**
+ * Normalize raw rows → sorted, deduped activity samples. `git` is dropped when
+ * configured; every other kind (incl. `idle` — the continuous-work pulse §3) is
+ * a real activity sample. Sort is by createdAt ASC; samples whose timestamps
+ * fall in the same `dedupRoundMs` bucket collapse to one (§9#7: a synchronous
+ * boundary row + the immediate agent snapshot can share a createdAt). A merged
+ * sample is human unless EVERY member is an agent, so supervision never gets
+ * mis-attributed to the agent.
+ */
+function normalize(
+  rows: TimelineSample[],
+  config: WorkTimeConfig,
+): NormSample[] {
+  const samples: NormSample[] = [];
+  for (const row of rows) {
+    const source = row.lastUpdatedSource;
+    if (config.excludeGit && source === 'git') continue;
+    samples.push({
+      t: toMs(row.createdAt),
+      isAgent: source === 'agent',
+      aiChatId: row.lastUpdatedAiChatId ?? null,
+      kind: row.kind ?? null,
+    });
+  }
+  samples.sort((a, b) => a.t - b.t);
+
+  if (config.dedupRoundMs <= 0 || samples.length < 2) return samples;
+
+  const deduped: NormSample[] = [];
+  for (const s of samples) {
+    const prev = deduped[deduped.length - 1];
+    if (prev && s.t - prev.t < config.dedupRoundMs) {
+      // Merge into the previous sample. Human wins the class; keep the earliest
+      // t; keep a non-null aiChatId if either has one (so a bare boundary row
+      // does not erase the run id).
+      prev.isAgent = prev.isAgent && s.isAgent;
+      prev.aiChatId = prev.aiChatId ?? s.aiChatId;
+      // Prefer the more specific kind (a real kind over a null/boundary) only
+      // matters for burst continuation; keep prev.kind (earliest) as-is.
+      continue;
+    }
+    deduped.push({ ...s });
+  }
+  return deduped;
+}
+
+/**
+ * Collapse consecutive same-run agent samples into one burst segment (§5.1) so a
+ * dense burst (8 snapshots in 7 minutes) contributes its wall-clock, not a count
+ * × block. A burst is broken by any sample NOT continuing the same aiChatId
+ * agent run: a non-agent sample, a `boundary` (actor transition), or a DIFFERENT
+ * aiChatId. Only an AGENT-sourced `idle` pulse with the SAME or a null aiChatId
+ * continues the burst (its label lags the real edit ≤ maxWait, well within
+ * rounding); a user-sourced `idle` (a human supervision pulse) breaks it.
+ */
+function collapse(samples: NormSample[], config: WorkTimeConfig): Segment[] {
+  const segments: Segment[] = [];
+  let burst: { chatId: string | null; tStart: number; tEnd: number } | null =
+    null;
+
+  const flush = () => {
+    if (!burst) return;
+    let tEnd = burst.tEnd;
+    if (config.burstCapMs != null && tEnd - burst.tStart > config.burstCapMs) {
+      tEnd = burst.tStart + config.burstCapMs;
+    }
+    segments.push({ tStart: burst.tStart, tEnd, isAgent: true });
+    burst = null;
+  };
+
+  for (const s of samples) {
+    // An agent-sourced idle pulse continues the current agent burst (same or
+    // null run id). A user-sourced idle (human supervision) must NOT be swallowed
+    // here — it falls through to the human branch so the session flips to `work`.
+    if (
+      burst &&
+      s.kind === 'idle' &&
+      s.isAgent &&
+      (s.aiChatId === burst.chatId || s.aiChatId == null)
+    ) {
+      burst.tEnd = s.t;
+      continue;
+    }
+    if (s.isAgent && s.kind !== 'boundary') {
+      if (burst && burst.chatId === s.aiChatId) {
+        burst.tEnd = s.t;
+      } else {
+        flush();
+        burst = { chatId: s.aiChatId, tStart: s.t, tEnd: s.t };
+      }
+      continue;
+    }
+    // A human sample, a boundary, or an agent-boundary: breaks the burst and is
+    // itself a zero-width segment (its class follows its own source).
+    flush();
+    segments.push({ tStart: s.t, tEnd: s.t, isAgent: s.isAgent });
+  }
+  flush();
+  return segments;
+}
+
+function gapThreshold(
+  a: Segment,
+  b: Segment,
+  config: WorkTimeConfig,
+): number {
+  return a.isAgent && b.isAgent ? config.agentTGap : config.tGap;
+}
+
+/** Merge intervals; overlapping OR touching intervals are unioned. */
+function unionDuration(intervals: Array<[number, number]>): number {
+  if (intervals.length === 0) return 0;
+  const sorted = [...intervals].sort((a, b) => a[0] - b[0]);
+  let total = 0;
+  let [curStart, curEnd] = sorted[0];
+  for (let i = 1; i < sorted.length; i++) {
+    const [s, e] = sorted[i];
+    if (s <= curEnd) {
+      if (e > curEnd) curEnd = e;
+    } else {
+      total += curEnd - curStart;
+      curStart = s;
+      curEnd = e;
+    }
+  }
+  total += curEnd - curStart;
+  return total;
+}
+
+/**
+ * #395 core — estimate time worked on a page from its history timeline (§5).
+ * Pure and deterministic: no DB, no clock, no I/O.
+ *
+ * Pipeline: normalize+dedup → collapse agent bursts → ONE sessionization pass
+ * over all segments (threshold depends on the pair: both-agent → agentTGap, else
+ * tGap; the last session is ALWAYS closed after the loop) → class per finished
+ * session (all-agent → agent_only, else work) → pad each session (multi-sample
+ * → [first−P_in, last+P_out]; lone scalar → [t−P_single, t]) → clip padding of
+ * adjacent DIFFERENT-class sessions at the raw-gap midpoint (so work/agent_only
+ * never overlap) → metrics are the union wall-clock within each class (union, not
+ * Σ, so overlaps never double, and cross-class-disjoint by the clip above).
+ */
+export function computeWorkTime(
+  rows: TimelineSample[],
+  config?: Partial<WorkTimeConfig>,
+): WorkTimeResult {
+  const cfg = resolveWorkTimeConfig(config);
+  const samples = normalize(rows, cfg);
+  const segments = collapse(samples, cfg);
+
+  // Sessionize — one pass over ALL segments.
+  const rawSessions: Segment[][] = [];
+  let cur: Segment[] | null = null;
+  for (const seg of segments) {
+    if (cur == null) {
+      cur = [seg];
+    } else {
+      const last = cur[cur.length - 1];
+      if (seg.tStart - last.tEnd <= gapThreshold(last, seg, cfg)) {
+        cur.push(seg);
+      } else {
+        rawSessions.push(cur);
+        cur = [seg];
+      }
+    }
+  }
+  if (cur != null) rawSessions.push(cur); // MUST close the last session (§5, §9#1)
+
+  // A finished session with BOTH its raw (unpadded) span and its padded bounds.
+  // `rawSessions` are already in ascending time order, so `built` is too.
+  interface BuiltSession {
+    rawStart: number;
+    rawEnd: number;
+    padStart: number;
+    padEnd: number;
+    cls: WorkSession['class'];
+  }
+  const built: BuiltSession[] = [];
+
+  for (const segs of rawSessions) {
+    const first = segs[0];
+    const last = segs[segs.length - 1];
+    const cls = segs.every((s) => s.isAgent) ? 'agent_only' : 'work';
+
+    let padStart: number;
+    let padEnd: number;
+    if (segs.length === 1 && first.tStart === first.tEnd) {
+      // Lone single-instant session (one scalar, or a one-snapshot agent run):
+      // pre-roll only, no invented "future" work (§5).
+      padStart = first.tStart - cfg.pSingle;
+      padEnd = first.tStart;
+    } else {
+      padStart = first.tStart - cfg.pIn;
+      padEnd = last.tEnd + cfg.pOut;
+    }
+
+    built.push({
+      rawStart: first.tStart,
+      rawEnd: last.tEnd,
+      padStart,
+      padEnd,
+      cls,
+    });
+  }
+
+  // Clip cross-class padding so a `work` and an `agent_only` session that abut
+  // never claim the same wall-clock. For each ADJACENT pair of DIFFERENT classes,
+  // cap the earlier session's trailing pad and the later session's leading pad at
+  // the MIDPOINT of the raw (unpadded) inactivity gap between them: the earlier
+  // padded interval then ends ≤ midpoint and the later one starts ≥ midpoint, so
+  // the two are disjoint (they touch at most at the midpoint). This makes the
+  // per-class unions (workMs / agentOnlyMs) cross-class-disjoint BY CONSTRUCTION
+  // — closing the double-count where a work session ending in an agent segment
+  // and a nearby agent_only session (gap in (agentTGap, pIn+pOut]) overlapped and
+  // were counted into both metrics (§5, §9). Within-class adjacency is left
+  // untouched: `unionDuration` already dedups it, and clipping there could perturb
+  // the per-class metric value.
+  for (let i = 1; i < built.length; i++) {
+    const a = built[i - 1];
+    const b = built[i];
+    if (a.cls === b.cls) continue;
+    const midpoint = (a.rawEnd + b.rawStart) / 2;
+    if (a.padEnd > midpoint) a.padEnd = midpoint;
+    if (b.padStart < midpoint) b.padStart = midpoint;
+  }
+
+  const sessions: WorkSession[] = [];
+  const workIvs: Array<[number, number]> = [];
+  const agentIvs: Array<[number, number]> = [];
+  for (const s of built) {
+    sessions.push({ start: s.padStart, end: s.padEnd, class: s.cls });
+    (s.cls === 'work' ? workIvs : agentIvs).push([s.padStart, s.padEnd]);
+  }
+
+  sessions.sort((a, b) => a.start - b.start);
+
+  return {
+    workMs: unionDuration(workIvs),
+    agentOnlyMs: unionDuration(agentIvs),
+    sessions,
+  };
+}
@@ -0,0 +1,15 @@
+export { computeWorkTime } from './compute-work-time';
+export { bucketByDay, zonedDayStart } from './bucket-by-day';
+export {
+  DEFAULT_WORK_TIME_CONFIG,
+  resolveWorkTimeConfig,
+} from './work-time.config';
+export type { WorkTimeConfig } from './work-time.config';
+export type {
+  TimelineSample,
+  WorkSession,
+  WorkTimeResult,
+  SessionClass,
+  DayWindow,
+  PerDay,
+} from './work-time.types';
@@ -0,0 +1,102 @@
+import {
+  IDLE_MAX_WAIT_USER,
+  IDLE_MAX_WAIT_AGENT,
+} from '../../../collaboration/constants';
+
+/**
+ * #395 — tunables for the work-time estimate (§10). Defaults are calibrated off
+ * #374's idle-pulse ceilings: after #374 a continuous editing session leaves a
+ * history row at least every ~IDLE_MAX_WAIT (10m user / 5m agent), so a gap
+ * WIDER than that ceiling contains un-pulsed idle time = (partial) inactivity.
+ * `tGap` therefore sits a little above the user ceiling, `agentTGap` a little
+ * above the agent ceiling — a gap within the threshold is pulse-backed and
+ * counts as work.
+ */
+export interface WorkTimeConfig {
+  /** user inactivity timeout: gap ≤ tGap between samples = continuous work. */
+  tGap: number;
+  /** timeout for a pair of consecutive agent samples (tighter than tGap). */
+  agentTGap: number;
+  /** pre-roll padding for a multi-sample session (work began before sample 1). */
+  pIn: number;
+  /** post-roll padding for a multi-sample session (work continued after last). */
+  pOut: number;
+  /** block for a lone single-sample session (pre-roll only, no invented future). */
+  pSingle: number;
+  /** drop `git`-source samples (they are not human/agent article work). */
+  excludeGit: boolean;
+  /** optional cap on one collapsed agent-burst segment's wall-clock (§9#3). */
+  burstCapMs?: number;
+  /** samples whose createdAt round to the same bucket dedup to one (§9#7). */
+  dedupRoundMs: number;
+}
+
+export const DEFAULT_WORK_TIME_CONFIG: WorkTimeConfig = {
+  // ~15m: IDLE_MAX_WAIT_USER (10m) + headroom. Empirically backcast on a real
+  // 307-snapshot article (≈24h at 15m matched the owner's estimate; 30/45m
+  // over-counted). See #395 §10.
+  tGap: 15 * 60 * 1000,
+  // ~7m: IDLE_MAX_WAIT_AGENT (5m) + headroom.
+  agentTGap: 7 * 60 * 1000,
+  pIn: 5 * 60 * 1000,
+  pOut: 5 * 60 * 1000,
+  pSingle: 2 * 60 * 1000,
+  excludeGit: true,
+  burstCapMs: undefined,
+  dedupRoundMs: 1000,
+};
+
+// Compile-time cross-check that the defaults really are pulse-anchored — if a
+// future edit moves the #374 ceilings, this reminds us to re-calibrate.
+void IDLE_MAX_WAIT_USER;
+void IDLE_MAX_WAIT_AGENT;
+
+/**
+ * Fill a partial config with defaults and validate it. Cross-class metric
+ * disjointness is guaranteed jointly by `computeWorkTime`'s adjacent-pair padding
+ * clip (it caps the padding of adjacent DIFFERENT-class sessions at the raw-gap
+ * midpoint) AND the two bounds enforced below (§5):
+ *   - `tGap ≥ pIn + pOut`: a session's own padding never exceeds its inactivity
+ *     window.
+ *   - `2·agentTGap ≥ pIn + pOut`: makes the adjacent-only clip provably COMPLETE.
+ *     A NON-adjacent (i, i+2) cross-class overlap could only arise from two
+ *     same-class sessions separated by a full intervening session of the other
+ *     class; that separation spans at least two inter-session gaps, each strictly
+ *     `> agentTGap`, so it is `> 2·agentTGap`. Requiring `2·agentTGap ≥ pIn + pOut`
+ *     means even the widest padded reach (pIn + pOut) cannot bridge it — so the
+ *     only cross-class overlaps possible are between ADJACENT sessions, which the
+ *     clip handles. `workMs`/`agentOnlyMs` are therefore disjoint by construction.
+ */
+export function resolveWorkTimeConfig(
+  partial?: Partial<WorkTimeConfig>,
+): WorkTimeConfig {
+  const config = { ...DEFAULT_WORK_TIME_CONFIG, ...(partial ?? {}) };
+
+  for (const key of [
+    'tGap',
+    'agentTGap',
+    'pIn',
+    'pOut',
+    'pSingle',
+    'dedupRoundMs',
+  ] as const) {
+    const value = config[key];
+    if (!Number.isFinite(value) || value < 0) {
+      throw new Error(`work-time config: ${key} must be a non-negative number`);
+    }
+  }
+  if (config.burstCapMs != null && config.burstCapMs <= 0) {
+    throw new Error('work-time config: burstCapMs must be > 0 when set');
+  }
+  if (config.tGap < config.pIn + config.pOut) {
+    throw new Error(
+      "work-time config: tGap must be ≥ pIn + pOut (a session's padding may not exceed its inactivity window)",
+    );
+  }
+  if (2 * config.agentTGap < config.pIn + config.pOut) {
+    throw new Error(
+      'work-time config: 2·agentTGap must be ≥ pIn + pOut (so non-adjacent cross-class padding cannot overlap)',
+    );
+  }
+  return config;
+}
@@ -0,0 +1,73 @@
+/**
+ * #395 — "time worked on an article" domain types.
+ *
+ * The estimate is built by sessionizing a page's `page_history` timeline on
+ * inactivity gaps (WakaTime-style), NOT by taking the span between the first and
+ * last edit (which over-counts sleep / lunch / idle days). See the design doc in
+ * issue #395 §5–§6.3 for the normative algorithm.
+ */
+
+/**
+ * A single `page_history` row projected for the work-time computation — the
+ * cheap columns only (no `content`). Produced by
+ * `PageHistoryRepo.findTimelineByPageId`. `createdAt` is whatever the DB driver
+ * hands back (Date); the pure core normalizes it to epoch-ms itself so it stays
+ * deterministic and DB-free.
+ */
+export interface TimelineSample {
+  createdAt: Date | string | number;
+  lastUpdatedById: string | null;
+  /** 'user' | 'agent' | 'git' | null (legacy autosave = human). */
+  lastUpdatedSource: string | null;
+  lastUpdatedAiChatId: string | null;
+  /** #370 tier: 'manual' | 'agent' | 'idle' | 'boundary' | null (legacy). */
+  kind: string | null;
+}
+
+/** A finished session's class (§5.1). */
+export type SessionClass = 'work' | 'agent_only';
+
+/**
+ * A finished session: absolute wall-clock bounds already padded with P_in/P_out
+ * (multi-sample) or P_single (single scalar), plus its class. This is enough for
+ * both the metrics and the per-day punch-card colouring.
+ */
+export interface WorkSession {
+  /** epoch-ms, inclusive lower bound (already P-padded). */
+  start: number;
+  /** epoch-ms, exclusive upper bound (already P-padded). */
+  end: number;
+  class: SessionClass;
+}
+
+/** Output of {@link computeWorkTime}. */
+export interface WorkTimeResult {
+  /** union wall-clock of `work` sessions, ms (the headline metric). */
+  workMs: number;
+  /** union wall-clock of `agent_only` sessions, ms (secondary). */
+  agentOnlyMs: number;
+  sessions: WorkSession[];
+}
+
+/** One activity window inside a calendar day (already clipped to the day). */
+export interface DayWindow {
+  /** epoch-ms. */
+  start: number;
+  /** epoch-ms. */
+  end: number;
+  class: SessionClass;
+}
+
+/** One calendar day of the punch-card (§6.3). */
+export interface PerDay {
+  /** epoch-ms of the local-midnight day start in the requested tz. */
+  day: number;
+  /** 'YYYY-MM-DD' in the requested tz — stable, tz-independent label. */
+  dayISO: string;
+  /** Σ of `work` windows this day, ms. Σ over days == workMs (invariant §6.3). */
+  activeMs: number;
+  /** Σ of `agent_only` windows this day, ms (drawn, NOT in activeMs). */
+  agentMs: number;
+  /** both classes, clipped to the day, sorted by start (for drawing). */
+  windows: DayWindow[];
+}
@@ -1,33 +1,56 @@
 import { Space } from '@docmost/db/types/entity.types';

-export class SearchResponseDto {
+// #529 A7 — the single per-hit SUPERSET returned by the unified search engine.
+// The web-UI reads id/highlight/icon/space/title/…; the MCP agent maps id→pageId
+// and reads snippet/score/path. `rank`/`highlight` are null for substring-only
+// hits (the web already falls back). Nothing the legacy web response carried is
+// dropped.
+export class SearchResultDto {
  id: string;
-  title: string;
+  // Alias of `id` for the MCP layer (it addresses pages by pageId).
+  pageId: string;
+  slugId: string;
  icon: string;
-  parentPageId: string;
+  title: string;
+  space?: Partial<Space>;
  creatorId: string;
-  rank: number;
-  highlight: string;
  createdAt: Date;
  updatedAt: Date;
-  space: Partial<Space>;
+  // ts_rank_cd of the FTS branch; null for substring-only hits.
+  rank: number | null;
+  // ts_headline marked HTML; null for substring-only hits.
+  highlight: string | null;
+  // Plain windowed snippet around the match (empty for titleOnly).
+  snippet: string;
+  // Ancestor titles root → direct parent ([] for a root page).
+  path: string[];
+  // Per-response ordering proxy (falls back to rank).
+  score: number;
+  // Which fields matched: 'title' and/or 'text'.
+  matchedFields: string[];
+  // Which parsed positive/required terms this hit matched.
+  matchedTerms: string[];
 }

-// Response shape for the opt-in agent-lookup mode (#443, `substring: true`).
-// Additive to the FTS response: carries the location (`path`), a windowed
-// `snippet` around the first match and a per-response sort `score`. The MCP
-// layer maps `id → pageId`; `slugId` is never exposed.
-export class SearchLookupResponseDto {
-  id: string;
-  slugId: string;
-  title: string;
-  parentPageId: string | null;
-  // Ancestor titles from the space root down to the direct parent; [] for a
-  // root page.
-  path: string[];
-  // ~300–500 chars around the first match (or a leading text window / extended
-  // ts_headline fallback).
-  snippet: string;
-  // 0..1 float, meaningful ONLY for sorting within one response.
-  score: number;
+// The paginated envelope (A5). `total` is the EXACT permission-filtered count of
+// pages matching the positive lexical query (fail-closed). `hasMore` is true when
+// more results exist WITHIN the fusion window; `truncatedAtCap` signals the match
+// set exceeded CANDIDATE_CAP and the tail is unreachable by pagination.
+export class SearchResponseDto {
+  items: SearchResultDto[];
+  total: number;
+  hasMore: boolean;
+  truncatedAtCap: boolean;
+  offset: number;
+  query: {
+    raw: string;
+    parsed: {
+      positive: string[];
+      required: string[];
+      excluded: string[];
+      reason?: string;
+    };
+    mode: 'or' | 'and';
+    match: string;
+  };
 }
@@ -1,16 +1,30 @@
 import {
  IsBoolean,
+  IsIn,
  IsNotEmpty,
  IsNumber,
  IsOptional,
  IsString,
+  MaxLength,
 } from 'class-validator';

 export class SearchDTO {
+  // Defense-in-depth cap on the raw query length. The real stack-depth bound is
+  // the parser's MAX_PARSED_TERMS term cap (see search-query-parser.ts); this
+  // just rejects absurd payloads early. 10k chars still comfortably holds any
+  // legitimate query.
  @IsNotEmpty()
  @IsString()
+  @MaxLength(10000)
  query: string;

+  // #529 A3 — match mode. `auto` (default) routes identifier-like terms
+  // (10.31.41, esp32, WB-MGE-30D86B) to the substring/trigram branch and words
+  // to full-text; `word`/`prefix`/`substring` are explicit overrides.
+  @IsOptional()
+  @IsIn(['auto', 'word', 'prefix', 'substring'])
+  match?: 'auto' | 'word' | 'prefix' | 'substring';
+
  @IsOptional()
  @IsString()
  spaceId: string;
@@ -33,15 +47,19 @@ export class SearchDTO {

  // --- Opt-in agent-lookup mode (#443). ------------------------------------
  // These fields are ADDITIVE and default-off: a web client that sends none of
-  // them gets byte-identical FTS behaviour and result shape. They are only read
-  // by the substring/path/snippet code path in SearchService.searchPage.
+  // them gets byte-identical FTS behaviour and result shape. In the unified #529
+  // engine, `parentPageId` and `titleOnly` are read by SearchService.searchPage
+  // (subtree scoping and title-only matching, respectively). `substring` is NOT
+  // read by the native driver — it is accepted-but-ignored, kept only for
+  // back-compat with the upstream lookup request shape.
  //
  // NOTE (standalone stdio vs stock upstream): stock upstream validates this DTO
  // with `whitelist: true`, so an older server silently strips these unknown
  // fields and the request degrades gracefully to the plain FTS behaviour.

-  // Enables the hybrid substring branch (title + text_content LIKE) merged with
-  // the existing FTS branch, plus tiered ranking, path and windowed snippet.
+  // Accepted-but-ignored by the #529 native driver (kept for upstream lookup
+  // back-compat). The unified engine ALWAYS runs the hybrid FTS + substring/
+  // trigram branches with tiered ranking, so this flag no longer toggles anything.
  @IsOptional()
  @IsBoolean()
  substring?: boolean;
@@ -0,0 +1,168 @@
+import {
+  parseSearchQuery,
+  hasPositiveRecall,
+  MAX_PARSED_TERMS,
+} from './search-query-parser';
+
+describe('parseSearchQuery — tokenization & operators (A2)', () => {
+  it('splits on whitespace into positive terms (OR recall)', () => {
+    const p = parseSearchQuery('стамбул роснефть');
+    expect(p.positive.map((t) => t.text)).toEqual(['стамбул', 'роснефть']);
+    expect(p.required).toEqual([]);
+    expect(p.excluded).toEqual([]);
+    expect(p.mode).toBe('or');
+  });
+
+  it('treats +term as required and -term as excluded', () => {
+    const p = parseSearchQuery('+кофейня -архив');
+    expect(p.required.map((t) => t.text)).toEqual(['кофейня']);
+    expect(p.excluded.map((t) => t.text)).toEqual(['архив']);
+    expect(p.positive).toEqual([]);
+  });
+
+  it('keeps a leading-operator-free hyphen/dot/colon token as ONE literal term', () => {
+    // WB-MGE-30D86B, 10.0.12.5, a:b — internal -,.,: are literal, one term each.
+    expect(parseSearchQuery('WB-MGE-30D86B').positive[0].text).toBe(
+      'WB-MGE-30D86B',
+    );
+    expect(parseSearchQuery('10.0.12.5').positive[0].text).toBe('10.0.12.5');
+    expect(parseSearchQuery('host:8080').positive[0].text).toBe('host:8080');
+  });
+
+  it('only a LEADING +/- is an operator; -архив excludes архив', () => {
+    const p = parseSearchQuery('-архив');
+    expect(p.excluded.map((t) => t.text)).toEqual(['архив']);
+    expect(p.positive).toEqual([]);
+  });
+
+  it('drops a bare "-" / "+" and an all-operator remainder', () => {
+    const p = parseSearchQuery('- + foo -- ++');
+    expect(p.positive.map((t) => t.text)).toEqual(['foo']);
+    expect(p.required).toEqual([]);
+    expect(p.excluded).toEqual([]);
+  });
+
+  it('parses a quoted phrase as one adjacency term', () => {
+    const p = parseSearchQuery('"воздушный шар" кофе');
+    expect(p.positive[0]).toMatchObject({ text: 'воздушный шар', branch: 'phrase' });
+    expect(p.positive[1].text).toBe('кофе');
+  });
+
+  it('applies +/- to a phrase', () => {
+    const req = parseSearchQuery('+"воздушный шар"');
+    expect(req.required[0]).toMatchObject({ text: 'воздушный шар', branch: 'phrase' });
+    const exc = parseSearchQuery('-"воздушный шар"');
+    expect(exc.excluded[0]).toMatchObject({ text: 'воздушный шар', branch: 'phrase' });
+  });
+
+  it('drops an unbalanced quote token', () => {
+    const p = parseSearchQuery('kafka "unclosed here');
+    expect(p.positive.map((t) => t.text)).toEqual(['kafka']);
+  });
+
+  it('strips tsquery metacharacters from a bare FTS term (no 500)', () => {
+    const p = parseSearchQuery('foo|bar');
+    // `|` is not an identifier signal → FTS branch; the metachar is stripped so
+    // the term becomes the two words that survive.
+    expect(p.positive[0].branch === 'fts' || p.positive[0].branch === 'ftsPrefix').toBe(true);
+    expect(p.positive[0].text).toBe('foo bar');
+  });
+});
+
+describe('parseSearchQuery — match=auto classification (A3)', () => {
+  it('routes identifier-like terms to the substring branch', () => {
+    expect(parseSearchQuery('10.31.41').positive[0].branch).toBe('substring');
+    expect(parseSearchQuery('esp32').positive[0].branch).toBe('substring');
+    expect(parseSearchQuery('WB-MGE-30D86B').positive[0].branch).toBe('substring');
+  });
+
+  it('routes purely-alphabetic words to the FTS (prefix) branch', () => {
+    expect(parseSearchQuery('печат').positive[0].branch).toBe('ftsPrefix');
+    expect(parseSearchQuery('ресторан').positive[0].branch).toBe('ftsPrefix');
+  });
+
+  it('explicit match overrides: word / prefix / substring', () => {
+    expect(parseSearchQuery('печат', { match: 'word' }).positive[0].branch).toBe('fts');
+    expect(parseSearchQuery('печат', { match: 'prefix' }).positive[0].branch).toBe(
+      'ftsPrefix',
+    );
+    expect(parseSearchQuery('печат', { match: 'substring' }).positive[0].branch).toBe(
+      'substring',
+    );
+  });
+});
+
+describe('parseSearchQuery — reasons & recall', () => {
+  it('only-negation yields reason only-negation and no positive recall', () => {
+    const p = parseSearchQuery('-архив');
+    expect(p.reason).toBe('only-negation');
+    expect(hasPositiveRecall(p)).toBe(false);
+  });
+
+  it('empty / whitespace / garbage yields reason empty', () => {
+    expect(parseSearchQuery('').reason).toBe('empty');
+    expect(parseSearchQuery('   ').reason).toBe('empty');
+    // A bare operator drops to nothing → empty (no exclusion survived).
+    expect(parseSearchQuery('+ -').reason).toBe('empty');
+  });
+
+  it('a required term alone IS positive recall (no reason)', () => {
+    const p = parseSearchQuery('+кофейня');
+    expect(p.reason).toBeUndefined();
+    expect(hasPositiveRecall(p)).toBe(true);
+  });
+
+  it('mode flag flows through', () => {
+    expect(parseSearchQuery('a b', { mode: 'and' }).mode).toBe('and');
+    expect(parseSearchQuery('a b').mode).toBe('or');
+  });
+});
+
+describe('parseSearchQuery — term cap (stack-depth guard)', () => {
+  it('caps the total parsed terms at MAX_PARSED_TERMS without throwing', () => {
+    // A pasted text block: far more words than the cap. The parser must bound the
+    // SQL tsquery nesting depth (else Postgres blows its stack → HTTP 500).
+    const words = Array.from({ length: 5000 }, (_, i) => `w${i}`);
+    let p!: ReturnType<typeof parseSearchQuery>;
+    expect(() => {
+      p = parseSearchQuery(words.join(' '));
+    }).not.toThrow();
+    const total = p.positive.length + p.required.length + p.excluded.length;
+    expect(total).toBe(MAX_PARSED_TERMS);
+    // Stable order: the FIRST cap terms are kept.
+    expect(p.positive.slice(0, 3).map((t) => t.text)).toEqual(['w0', 'w1', 'w2']);
+    expect(p.positive[MAX_PARSED_TERMS - 1].text).toBe(`w${MAX_PARSED_TERMS - 1}`);
+  });
+
+  it('counts positive + required + excluded together toward the cap', () => {
+    // Interleave operators so overflow can fall on any bucket. Total must still
+    // never exceed the cap, and the first cap terms (in stable order) win.
+    const tokens: string[] = [];
+    for (let i = 0; i < 200; i++) {
+      const op = i % 3 === 0 ? '+' : i % 3 === 1 ? '-' : '';
+      tokens.push(`${op}t${i}`);
+    }
+    const p = parseSearchQuery(tokens.join(' '));
+    const total = p.positive.length + p.required.length + p.excluded.length;
+    expect(total).toBe(MAX_PARSED_TERMS);
+    // t0 (+, required) and t1 (-, excluded) and t2 (bare, positive) are all within
+    // the first cap tokens → each bucket got its leading terms.
+    expect(p.required[0].text).toBe('t0');
+    expect(p.excluded[0].text).toBe('t1');
+    expect(p.positive[0].text).toBe('t2');
+  });
+
+  it('leaves a normal (<= cap) query completely unchanged', () => {
+    const p = parseSearchQuery('+кофейня -архив "воздушный шар" ресторан 10.31.41');
+    expect(p.required.map((t) => t.text)).toEqual(['кофейня']);
+    expect(p.excluded.map((t) => t.text)).toEqual(['архив']);
+    expect(p.positive.map((t) => t.text)).toEqual([
+      'воздушный шар',
+      'ресторан',
+      '10.31.41',
+    ]);
+    // Phrase / substring branch handling survives under the cap.
+    expect(p.positive[0].branch).toBe('phrase');
+    expect(p.positive[2].branch).toBe('substring');
+  });
+});
@@ -0,0 +1,242 @@
+// #529 Phase A — server-side query parser (the SINGLE source of query semantics).
+//
+// Clients (web-UI, MCP agent, public share) send a RAW query string plus flags
+// (`match`, `mode`); ALL query interpretation happens HERE, so every consumer
+// gets identical operator/phrase/morphology behaviour. The parser is PURE (no
+// SQL, no DB) so it is exhaustively unit-testable; SearchService turns the parsed
+// AST into a parameterized tsquery/predicate tree (never string-concatenated SQL).
+//
+// Grammar (A2):
+//   - Whitespace splits tokens, but a double-quoted run is ONE token ("a b" is a
+//     phrase). An unbalanced quote is dropped.
+//   - A token is an OPERATOR token only when it STARTS with `+` or `-`, the
+//     remainder is non-empty, and the remainder is not itself only operators.
+//     `+`/`-` inside a token (`WB-MGE-30D86B`, `10.0.12.5`, `a:b`) is a LITERAL —
+//     the token is a single term. A bare `-`/`+` is dropped.
+//   - `"phrase"` → phrase term; `+"phrase"`/`-"phrase"` apply the operator to it.
+//   - Positive terms (bare + phrase, no operator) form the OR recall set.
+//     `+term` is a REQUIRED predicate, `-term` an EXCLUDED predicate (A2): both
+//     are applied in SQL WHERE against the whole candidate set, not folded into
+//     the positive tsquery.
+//   - Only-negation (no positive term) short-circuits to an empty result with
+//     reason `only-negation` (never runs a costly NOT-scan).
+
+export type SearchMatchMode = 'auto' | 'word' | 'prefix' | 'substring';
+export type SearchBooleanMode = 'or' | 'and';
+
+// Hard cap on the total number of parsed terms (positive + required + excluded).
+// SearchService folds each FTS term into a LEFT-NESTED SQL tsquery expression
+// `(((t1)||(t2))||(t3))…`, embedded several times per query — so nesting depth
+// grows with the term count. A pasted text block (thousands of words) would nest
+// deep enough to blow Postgres' `stack depth limit` → an ERROR → HTTP 500 for the
+// caller. Capping in the parser bounds that depth for EVERY consumer (web / MCP /
+// share), since they all route through here. 64 comfortably covers any real query
+// while keeping the SQL nesting shallow. Overflow terms (beyond the first 64, in
+// stable order) are dropped rather than throwing.
+export const MAX_PARSED_TERMS = 64;
+
+// How a single term is matched against the index.
+//   - 'fts'       : full-text lexeme, exact (no trailing prefix).
+//   - 'ftsPrefix' : full-text lexeme with a `:*` prefix match.
+//   - 'phrase'    : an adjacency phrase (phraseto_tsquery).
+//   - 'substring' : a literal LOWER(f_unaccent(col)) LIKE '%needle%' branch
+//                   (identifiers the tokenizer mangles: IPs, hostnames, IDs).
+export type SearchTermBranch = 'fts' | 'ftsPrefix' | 'phrase' | 'substring';
+
+export interface ParsedTerm {
+  // The user-visible term text, operator stripped, quotes removed. This is what
+  // `matchedTerms` echoes back per hit.
+  text: string;
+  branch: SearchTermBranch;
+}
+
+export interface ParsedQuery {
+  raw: string;
+  // OR-recall set (bare + phrase terms with no operator).
+  positive: ParsedTerm[];
+  // AND predicates (`+term`) — the candidate MUST match each of these.
+  required: ParsedTerm[];
+  // NOT predicates (`-term`) — the candidate must match NONE of these.
+  excluded: ParsedTerm[];
+  mode: SearchBooleanMode;
+  // Set only when the query yields no positive recall: 'empty' (nothing usable)
+  // or 'only-negation' (there were exclusions but no positive term).
+  reason?: 'empty' | 'only-negation';
+}
+
+interface RawToken {
+  op: '' | '+' | '-';
+  kind: 'word' | 'phrase';
+  text: string;
+}
+
+// tsquery metacharacters that must never reach to_tsquery from a bare term — they
+// are what turned adversarial input into a 500 before (#139). Stripped for the FTS
+// branch; the substring branch keeps them (they are literal there).
+const TSQUERY_META = /[:&|!()*<>\\]+/g;
+
+// A term is "identifier-like" when it carries a digit or one of . _ : / - AND is
+// not purely alphabetic (letters only). Such tokens (10.31.41, esp32,
+// WB-MGE-30D86B) are mangled by the FTS tokenizer, so `match: auto` routes them
+// to the substring branch. A purely-alphabetic word (печат, ресторан) stays FTS.
+const IDENTIFIER_SIGNAL = /[0-9._:/\\-]/;
+const PURELY_ALPHA = /^\p{L}+$/u;
+
+function isIdentifierLike(text: string): boolean {
+  return IDENTIFIER_SIGNAL.test(text) && !PURELY_ALPHA.test(text);
+}
+
+// Clean a bare term for the FTS branch: NFC-normalize, drop tsquery metacharacters
+// and collapse whitespace. Returns '' when nothing usable remains.
+export function cleanFtsLexeme(raw: string): string {
+  return (raw ?? '')
+    .normalize('NFC')
+    .replace(TSQUERY_META, ' ')
+    .replace(/\s+/g, ' ')
+    .trim();
+}
+
+// Split a raw query into tokens, honouring double quotes and a single leading
+// +/- operator. Unbalanced quotes and bare operators are dropped.
+function tokenize(raw: string): RawToken[] {
+  const tokens: RawToken[] = [];
+  const s = raw ?? '';
+  let i = 0;
+  const n = s.length;
+
+  const isSpace = (c: string) => /\s/.test(c);
+
+  while (i < n) {
+    // Skip leading whitespace.
+    while (i < n && isSpace(s[i])) i++;
+    if (i >= n) break;
+
+    let op: '' | '+' | '-' = '';
+    // A single leading +/- is a tentative operator. Only ONE leading operator is
+    // consumed; a second (`--x`) leaves `-x` as the remainder (a literal dash).
+    if (s[i] === '+' || s[i] === '-') {
+      op = s[i] as '+' | '-';
+      i++;
+    }
+
+    if (i < n && s[i] === '"') {
+      // Quoted phrase: read until the closing quote.
+      const close = s.indexOf('"', i + 1);
+      if (close === -1) {
+        // Unbalanced quote → drop this token and everything the open quote would
+        // have consumed (the rest of the string).
+        break;
+      }
+      const phrase = s.slice(i + 1, close);
+      i = close + 1;
+      if (phrase.trim().length > 0) {
+        tokens.push({ op, kind: 'phrase', text: phrase.trim() });
+      }
+      continue;
+    }
+
+    // Bare word: read until the next whitespace.
+    let j = i;
+    while (j < n && !isSpace(s[j])) j++;
+    const word = s.slice(i, j);
+    i = j;
+
+    // A bare operator (`-`/`+` with no remainder) or an all-operator remainder is
+    // dropped.
+    if (word.length === 0) continue;
+    if (op && /^[+-]+$/.test(word)) continue;
+
+    tokens.push({ op, kind: 'word', text: word });
+  }
+
+  return tokens;
+}
+
+// Resolve the match branch for a single term given the global match mode.
+function branchForTerm(
+  text: string,
+  kind: 'word' | 'phrase',
+  mode: SearchMatchMode,
+): SearchTermBranch {
+  if (kind === 'phrase') return 'phrase';
+  switch (mode) {
+    case 'word':
+      return 'fts';
+    case 'prefix':
+      return 'ftsPrefix';
+    case 'substring':
+      return 'substring';
+    case 'auto':
+    default:
+      // Identifiers the tokenizer mangles go to substring; words get a prefix
+      // FTS match (so `печат` still finds `печатать`, but `печат` no longer drags
+      // in `впечатления` because the russian stemmer anchors the stem).
+      return isIdentifierLike(text) ? 'substring' : 'ftsPrefix';
+  }
+}
+
+/**
+ * Parse a raw user query + flags into a structured, SQL-agnostic AST.
+ * Pure and total: never throws, always returns a ParsedQuery.
+ */
+export function parseSearchQuery(
+  raw: string,
+  opts: { match?: SearchMatchMode; mode?: SearchBooleanMode } = {},
+): ParsedQuery {
+  const match: SearchMatchMode = opts.match ?? 'auto';
+  const mode: SearchBooleanMode = opts.mode ?? 'or';
+
+  const positive: ParsedTerm[] = [];
+  const required: ParsedTerm[] = [];
+  const excluded: ParsedTerm[] = [];
+
+  for (const tok of tokenize(raw)) {
+    // For an FTS branch, the token must survive metacharacter cleaning; for the
+    // substring/phrase branch the literal text is used. A term that cleans to
+    // nothing AND is not usable as a substring is dropped.
+    const branch = branchForTerm(tok.text, tok.kind, match);
+
+    let usableText: string;
+    if (branch === 'fts' || branch === 'ftsPrefix') {
+      usableText = cleanFtsLexeme(tok.text);
+    } else {
+      // phrase / substring keep the literal (trimmed) text.
+      usableText = tok.text.trim();
+    }
+    if (!usableText) continue;
+
+    // Stack-depth guard: stop after MAX_PARSED_TERMS surviving terms (positive +
+    // required + excluded, combined) so the SQL tsquery nesting stays shallow.
+    // The first 64 terms are kept in stable order; the rest are dropped.
+    if (positive.length + required.length + excluded.length >= MAX_PARSED_TERMS) {
+      break;
+    }
+
+    const term: ParsedTerm = { text: usableText, branch };
+
+    if (tok.op === '+') required.push(term);
+    else if (tok.op === '-') excluded.push(term);
+    else positive.push(term);
+  }
+
+  const parsed: ParsedQuery = { raw: raw ?? '', positive, required, excluded, mode };
+
+  if (positive.length === 0) {
+    // Required terms with no positive recall still form a valid positive set (the
+    // required predicates ARE the recall). Only when there is neither a positive
+    // nor a required term is the query empty / only-negation.
+    if (required.length === 0) {
+      parsed.reason = excluded.length > 0 ? 'only-negation' : 'empty';
+    }
+  }
+
+  return parsed;
+}
+
+/**
+ * Does this parsed query have any positive recall to run? False means we must
+ * short-circuit to an empty result (with `reason`), never a costly NOT-only scan.
+ */
+export function hasPositiveRecall(parsed: ParsedQuery): boolean {
+  return parsed.positive.length > 0 || parsed.required.length > 0;
+}
@@ -1,19 +1,14 @@
-import {
-  computeLookupScore,
-  escapeLikePattern,
-  SearchLookupTier,
-} from './search.service';
+import { escapeLikePattern } from './search.service';

 /**
- * Pure-function coverage for the #443 agent-lookup helpers:
- *  - escapeLikePattern: LIKE-metacharacter escaping so `%`/`_`/`\` are literals
- *    (the acceptance-table requirement that a query of `%` or `_` does NOT match
- *    everything);
- *  - computeLookupScore: the tiered 0..1 ranking score, where a stronger tier
- *    always outranks a weaker one regardless of the in-tier secondary signal.
+ * Pure-function coverage for `escapeLikePattern` — LIKE-metacharacter escaping so
+ * `%`/`_`/`\` are matched literally (the acceptance requirement that a query of
+ * `%` or `_` does NOT match everything, #529 acceptance #10). The substring
+ * branch's DB behaviour is covered by the integration spec.
 *
- * The DB-touching branch (substring UNION FTS, path CTE, snippet window) is
- * covered by the integration spec against the real schema.
+ * NOTE (#529): the old tiered `computeLookupScore` was replaced by RRF rank
+ * fusion in the unified engine, so its unit coverage moved to the integration
+ * ordering tests; only the escaping helper remains a pure unit here.
 */
 describe('escapeLikePattern', () => {
  it('escapes the LIKE metacharacters % _ and \\', () => {
@@ -43,53 +38,3 @@ describe('escapeLikePattern', () => {
    expect(escapeLikePattern(null as any)).toBe('');
  });
 });
-
-describe('computeLookupScore', () => {
-  it('keeps every score within (0, 1]', () => {
-    for (const tier of [
-      SearchLookupTier.TITLE_EXACT,
-      SearchLookupTier.TITLE_SUBSTRING,
-      SearchLookupTier.TEXT,
-    ]) {
-      for (const secondary of [0, 0.001, 1, 100, 1e6]) {
-        const s = computeLookupScore({ tier, secondary });
-        expect(s).toBeGreaterThan(0);
-        expect(s).toBeLessThanOrEqual(1);
-      }
-    }
-  });
-
-  it('a stronger tier ALWAYS outranks a weaker tier, whatever the secondary', () => {
-    // Weak tier with a huge secondary must still lose to a strong tier with a
-    // tiny secondary — tiers dominate.
-    const strongLowSecondary = computeLookupScore({
-      tier: SearchLookupTier.TITLE_EXACT,
-      secondary: 0,
-    });
-    const weakHighSecondary = computeLookupScore({
-      tier: SearchLookupTier.TEXT,
-      secondary: 1e9,
-    });
-    expect(strongLowSecondary).toBeGreaterThan(weakHighSecondary);
-  });
-
-  it('within a tier a larger secondary sorts higher', () => {
-    const lo = computeLookupScore({
-      tier: SearchLookupTier.TEXT,
-      secondary: 0.1,
-    });
-    const hi = computeLookupScore({
-      tier: SearchLookupTier.TEXT,
-      secondary: 5,
-    });
-    expect(hi).toBeGreaterThan(lo);
-  });
-
-  it('treats a negative/absent secondary as 0', () => {
-    const zero = computeLookupScore({ tier: SearchLookupTier.TEXT, secondary: 0 });
-    expect(computeLookupScore({ tier: SearchLookupTier.TEXT })).toBe(zero);
-    expect(
-      computeLookupScore({ tier: SearchLookupTier.TEXT, secondary: -5 }),
-    ).toBe(zero);
-  });
-});
@@ -1,74 +1,45 @@
 import { SearchService } from './search.service';

 /**
- * Coverage for SearchService.searchPage query-mode selection (search.service.ts
- * @25). searchPage chooses HOW the result set is scoped — by explicit space, by
- * the authenticated user's member spaces, or by a share — and must return an
- * empty set (without leaking data) for every disallowed combination.
+ * Unit coverage for SearchService.searchPage SCOPE-SECURITY early returns — the
+ * branches that must yield an empty result WITHOUT ever touching the DB, so they
+ * can leak nothing. The happy-path scope SQL (explicit space / member spaces /
+ * share id set) is covered against the real schema in the integration spec.
 *
- * The kysely query builder is mocked with the same chainable pattern as the
- * existing search.service.spec.ts: every builder method returns the same builder
- * and `.execute()` resolves the supplied rows. Each `.where(...)` call is
- * recorded so we can assert exactly which scope clause was applied — that is the
- * mutation-resistant signal that distinguishes one query mode from another.
- *
- * These specs catch cross-space / cross-workspace search leakage and
- * share-scope bypass (data exposure).
+ * Every case here returns BEFORE the raw-SQL candidate query runs, so a bare `db`
+ * stub (never called) is enough — a call to it would itself be a failure signal.
 */
-describe('SearchService.searchPage — query-mode selection', () => {
-  // Build a chainable selectFrom('pages') builder that records its calls. The
-  // builder is returned from `db.selectFrom` and is the single object every
-  // chained call mutates/returns, mirroring the existing spec's pattern.
-  function makeBuilder(rows: Array<{ id: string; highlight?: string }>) {
-    const builder: any = {};
-    builder.select = jest.fn(() => builder);
-    builder.where = jest.fn(() => builder);
-    builder.$if = jest.fn(() => builder);
-    builder.orderBy = jest.fn(() => builder);
-    builder.limit = jest.fn(() => builder);
-    builder.offset = jest.fn(() => builder);
-    builder.execute = jest.fn(async () => rows);
-    return builder;
-  }
-
+describe('SearchService.searchPage — scope-security early returns', () => {
  function makeService(opts?: {
-    rows?: Array<{ id: string; highlight?: string }>;
    share?: any;
    isRestricted?: boolean;
-    descendants?: Array<{ id: string }>;
+    memberSpaceIds?: string[];
  }) {
-    const builder = makeBuilder(opts?.rows ?? []);
-
-    const db: any = {
-      selectFrom: jest.fn(() => builder),
-    };
-
-    // `getUserSpaceIdsQuery` returns a sub-query object that searchPage passes
-    // straight into `.where('spaceId', 'in', <subquery>)`. A sentinel is enough
-    // to assert the user-scoped branch was taken.
-    const userSpaceIdsQuery = { __userSpaceIdsQuery: true };
+    // A db that THROWS if touched — these branches must not reach SQL.
+    const db: any = new Proxy(
+      {},
+      {
+        get() {
+          throw new Error('db must not be touched on an empty-scope branch');
+        },
+      },
+    );

    const pageRepo = {
-      // `.select((eb) => this.pageRepo.withSpace(eb))` — value ignored by stub.
-      withSpace: jest.fn(() => ({ __withSpace: true })),
-      getPageAndDescendantsExcludingRestricted: jest
-        .fn()
-        .mockResolvedValue(opts?.descendants ?? []),
+      getPageAndDescendantsExcludingRestricted: jest.fn(),
+      getPageAndDescendants: jest.fn(),
    };
    const shareRepo = {
      findById: jest.fn().mockResolvedValue(opts?.share ?? null),
    };
    const spaceMemberRepo = {
-      getUserSpaceIdsQuery: jest.fn(() => userSpaceIdsQuery),
+      getUserSpaceIds: jest.fn().mockResolvedValue(opts?.memberSpaceIds ?? []),
    };
    const pagePermissionRepo = {
      hasRestrictedAncestor: jest
        .fn()
        .mockResolvedValue(opts?.isRestricted ?? false),
-      // Let everything through page-level permission filtering by default.
-      filterAccessiblePageIds: jest
-        .fn()
-        .mockImplementation(async ({ pageIds }: { pageIds: string[] }) => pageIds),
+      filterAccessiblePageIds: jest.fn(),
    };

    const service = new SearchService(
@@ -78,145 +49,81 @@ describe('SearchService.searchPage — query-mode selection', () => {
      spaceMemberRepo as any,
      pagePermissionRepo as any,
    );
-
-    return {
-      service,
-      db,
-      builder,
-      pageRepo,
-      shareRepo,
-      spaceMemberRepo,
-      pagePermissionRepo,
-      userSpaceIdsQuery,
-    };
+    return { service, pageRepo, shareRepo, spaceMemberRepo, pagePermissionRepo };
  }

-  const whereCallFor = (builder: any, column: any) =>
-    builder.where.mock.calls.find((c: any[]) => c[0] === column);
-
-  it('returns {items:[]} for a blank query WITHOUT touching the DB', async () => {
-    const { service, db } = makeService();
-
+  it('returns total:0 for a blank query WITHOUT touching the DB or any repo', async () => {
+    const { service, shareRepo, spaceMemberRepo } = makeService();
    const result = await service.searchPage(
      { query: '' } as any,
      { userId: 'user-1', workspaceId: 'ws-1' },
    );
-
-    expect(result).toEqual({ items: [] });
-    // Blank query is rejected before any query builder is constructed.
-    expect(db.selectFrom).not.toHaveBeenCalled();
+    expect(result.items).toEqual([]);
+    expect(result.total).toBe(0);
+    expect(shareRepo.findById).not.toHaveBeenCalled();
+    expect(spaceMemberRepo.getUserSpaceIds).not.toHaveBeenCalled();
  });

-  it('scopes to the explicit spaceId branch', async () => {
-    const { service, builder, db, spaceMemberRepo, shareRepo } = makeService({
-      rows: [{ id: 'p-1' }],
-    });
-
+  it('only-negation short-circuits with reason "only-negation", never scanning', async () => {
+    const { service, spaceMemberRepo } = makeService();
    const result = await service.searchPage(
-      { query: 'plan', spaceId: 'space-42' } as any,
+      { query: '-архив' } as any,
      { userId: 'user-1', workspaceId: 'ws-1' },
    );
-
-    expect(db.selectFrom).toHaveBeenCalledWith('pages');
-    // The explicit-space branch adds exactly `.where('spaceId', '=', 'space-42')`.
-    expect(whereCallFor(builder, 'spaceId')).toEqual([
-      'spaceId',
-      '=',
-      'space-42',
-    ]);
-    // It must NOT fall through to the user-member-spaces or share branch.
-    expect(spaceMemberRepo.getUserSpaceIdsQuery).not.toHaveBeenCalled();
-    expect(shareRepo.findById).not.toHaveBeenCalled();
-    expect(result.items.map((i: any) => i.id)).toEqual(['p-1']);
+    expect(result.total).toBe(0);
+    expect(result.query.parsed.reason).toBe('only-negation');
+    // Never resolves scope (returns before) — no expensive NOT-only scan.
+    expect(spaceMemberRepo.getUserSpaceIds).not.toHaveBeenCalled();
  });

-  it('scopes an authenticated user WITHOUT spaceId to their member spaces', async () => {
-    const { service, builder, spaceMemberRepo, userSpaceIdsQuery, shareRepo } =
-      makeService({ rows: [{ id: 'p-9' }] });
-
-    await service.searchPage(
-      { query: 'plan' } as any,
-      { userId: 'user-7', workspaceId: 'ws-1' },
-    );
-
-    // The user-scoped branch resolves the member-spaces sub-query for that user
-    // and restricts both spaceId (to that sub-query) and workspaceId.
-    expect(spaceMemberRepo.getUserSpaceIdsQuery).toHaveBeenCalledWith('user-7');
-    expect(whereCallFor(builder, 'spaceId')).toEqual([
-      'spaceId',
-      'in',
-      userSpaceIdsQuery,
-    ]);
-    expect(whereCallFor(builder, 'workspaceId')).toEqual([
-      'workspaceId',
-      '=',
-      'ws-1',
-    ]);
-    // Authenticated user path must not consult shares.
-    expect(shareRepo.findById).not.toHaveBeenCalled();
-  });
-
-  it('returns {items:[]} when the share belongs to a DIFFERENT workspace', async () => {
-    const { service, builder, shareRepo, pagePermissionRepo } = makeService({
-      share: {
-        id: 'share-1',
-        pageId: 'page-1',
-        workspaceId: 'OTHER-ws',
-        includeSubPages: false,
-      },
+  it('returns empty when the share belongs to a DIFFERENT workspace (no leak)', async () => {
+    const { service, shareRepo, pagePermissionRepo } = makeService({
+      share: { id: 's1', pageId: 'p1', workspaceId: 'OTHER', includeSubPages: false },
    });
-
    const result = await service.searchPage(
-      { query: 'plan', shareId: 'share-1' } as any,
+      { query: 'plan', shareId: 's1' } as any,
      { workspaceId: 'ws-1' },
    );
-
-    expect(shareRepo.findById).toHaveBeenCalledWith('share-1');
-    expect(result).toEqual({ items: [] });
-    // Workspace mismatch short-circuits before any restricted-ancestor / id
-    // scoping or DB execution: no leak across workspaces.
+    expect(shareRepo.findById).toHaveBeenCalledWith('s1');
+    expect(result.items).toEqual([]);
+    // Workspace mismatch short-circuits before restricted-ancestor / enumeration.
    expect(pagePermissionRepo.hasRestrictedAncestor).not.toHaveBeenCalled();
-    expect(builder.execute).not.toHaveBeenCalled();
  });

-  it('returns {items:[]} when the shared page has a restricted ancestor', async () => {
-    const { service, builder, pagePermissionRepo, pageRepo } = makeService({
-      share: {
-        id: 'share-1',
-        pageId: 'page-1',
-        workspaceId: 'ws-1',
-        includeSubPages: true,
-      },
+  it('returns empty when the shared page has a restricted ancestor', async () => {
+    const { service, pagePermissionRepo, pageRepo } = makeService({
+      share: { id: 's1', pageId: 'p1', workspaceId: 'ws-1', includeSubPages: true },
      isRestricted: true,
    });
-
    const result = await service.searchPage(
-      { query: 'plan', shareId: 'share-1' } as any,
+      { query: 'plan', shareId: 's1' } as any,
      { workspaceId: 'ws-1' },
    );
-
-    expect(pagePermissionRepo.hasRestrictedAncestor).toHaveBeenCalledWith(
-      'page-1',
-    );
-    expect(result).toEqual({ items: [] });
-    // Restricted ancestor must block before page enumeration and DB execution.
+    expect(pagePermissionRepo.hasRestrictedAncestor).toHaveBeenCalledWith('p1');
+    expect(result.items).toEqual([]);
    expect(
      pageRepo.getPageAndDescendantsExcludingRestricted,
    ).not.toHaveBeenCalled();
-    expect(builder.execute).not.toHaveBeenCalled();
  });

-  it('returns {items:[]} with no userId, no spaceId and no shareId', async () => {
-    const { service, builder, shareRepo } = makeService();
-
+  it('returns empty with no userId, no spaceId and no shareId', async () => {
+    const { service, shareRepo } = makeService();
    const result = await service.searchPage(
      { query: 'plan' } as any,
      { workspaceId: 'ws-1' },
    );
-
-    expect(result).toEqual({ items: [] });
-    // The catch-all else returns empty without scoping/executing or hitting shares.
+    expect(result.items).toEqual([]);
    expect(shareRepo.findById).not.toHaveBeenCalled();
-    expect(builder.execute).not.toHaveBeenCalled();
+  });
+
+  it('an authenticated user with NO member spaces gets an empty result', async () => {
+    const { service, spaceMemberRepo } = makeService({ memberSpaceIds: [] });
+    const result = await service.searchPage(
+      { query: 'plan' } as any,
+      { userId: 'user-1', workspaceId: 'ws-1' },
+    );
+    expect(spaceMemberRepo.getUserSpaceIds).toHaveBeenCalledWith('user-1');
+    expect(result.items).toEqual([]);
+    expect(result.total).toBe(0);
  });
 });
@@ -1,4 +1,4 @@
-import { SearchService, buildTsQuery } from './search.service';
+import { SearchService } from './search.service';

 describe('SearchService', () => {
  it('should be defined', () => {
@@ -99,59 +99,3 @@ describe('SearchService.searchSuggestions — onlyTemplates filter', () => {
    expect(isTemplateWhereCall(pageBuilder)).toBeUndefined();
  });
 });
-
-// Unit tests for `buildTsQuery` (extracted from search.service.ts). It turns a raw
-// user query into a prefix tsquery string fed to `to_tsquery('english', ...)`.
-//
-// REAL BUG (Gitea #139, item 10): the previous inline `tsquery(query.trim() + '*')`
-// let to_tsquery operator characters through, so adversarial inputs could produce a
-// fragment that to_tsquery rejects -> 500. The extraction sanitizes the input
-// (strip everything but letters/numbers/whitespace) so these inputs degrade to a
-// safe, neutral query with NO throw, while normal queries keep working.
-describe('buildTsQuery', () => {
-  it('builds a prefix query for a normal single word', () => {
-    expect(buildTsQuery('hello')).toBe('hello:*');
-  });
-
-  it('joins multiple words with AND and a trailing prefix match', () => {
-    expect(buildTsQuery('foo bar')).toBe('foo&bar:*');
-  });
-
-  it('preserves accented and non-Latin words', () => {
-    expect(buildTsQuery('héllo café')).toBe('héllo&café:*');
-    expect(buildTsQuery('日本語')).toBe('日本語:*');
-  });
-
-  it('neutralizes to_tsquery operator inputs without throwing', () => {
-    // Each of these previously risked an invalid to_tsquery -> 500. They must now
-    // produce a safe (here empty) query and never throw.
-    for (const input of ['&', '!', '*', '<->', '\\']) {
-      expect(() => buildTsQuery(input)).not.toThrow();
-      expect(buildTsQuery(input)).toBe('');
-    }
-  });
-
-  it('handles stopword-only input safely', () => {
-    // pg-tsquery still tokenizes stopwords; to_tsquery reduces them to nothing.
-    // The important contract is: no throw, and a deterministic string.
-    expect(() => buildTsQuery('the a of')).not.toThrow();
-    expect(buildTsQuery('the a of')).toBe('the&a&of:*');
-  });
-
-  it('returns empty string for empty / whitespace-only / null-ish input', () => {
-    expect(buildTsQuery('')).toBe('');
-    expect(buildTsQuery('   ')).toBe('');
-    expect(buildTsQuery(undefined as unknown as string)).toBe('');
-  });
-
-  it('handles a very long input without throwing', () => {
-    const long = 'a'.repeat(10000);
-    expect(() => buildTsQuery(long)).not.toThrow();
-    expect(buildTsQuery(long)).toBe(`${long}:*`);
-  });
-
-  it('strips punctuation embedded in otherwise valid words', () => {
-    expect(buildTsQuery('c++ code')).toBe('c&code:*');
-    expect(buildTsQuery('a-b-c')).toBe('a&b&c:*');
-  });
-});
@@ -1,5 +1,6 @@
 import {
  IsBoolean,
+  IsIn,
  IsNotEmpty,
  IsOptional,
  IsString,
@@ -18,6 +19,13 @@ export class CreateShareDto {
  @IsOptional()
  @IsBoolean()
  searchIndexing: boolean;
+
+  // #370 Stage B — publication mode. 'live' (default) serves the current draft;
+  // 'approved' serves the last manually-saved version (page_history.kind
+  // ='manual'). Mutually exclusive with includeSubPages (enforced server-side).
+  @IsOptional()
+  @IsIn(['live', 'approved'])
+  publishedMode?: 'live' | 'approved';
 }

 export class UpdateShareDto extends CreateShareDto {
@@ -39,6 +39,7 @@ function buildService() {
    tokenService as any,
    {} as any, // transclusionService (unused)
    workspaceRepo as any,
+    {} as any, // pageHistoryRepo (unused on this path)
  );
 }

@@ -39,6 +39,7 @@ function buildService(over: {
    {} as any, // tokenService
    {} as any, // transclusionService
    {} as any, // workspaceRepo
+    {} as any, // pageHistoryRepo
  );

  jest
@@ -62,6 +62,7 @@ function buildService(opts: {
    tokenService as any,
    {} as any, // transclusionService (unused)
    workspaceRepo as any,
+    {} as any, // pageHistoryRepo (unused on this path)
  );

  // getSharedPage resolves the share via getShareForPage (a raw db query).
@@ -181,6 +182,7 @@ describe('ShareService.lookupTransclusionForShare htmlEmbed kill-switch (real co
      tokenService as any,
      transclusionService as any,
      workspaceRepo as any,
+      {} as any, // pageHistoryRepo (unused on this path)
    );

    // isSharingAllowed and getShareForPage hit the raw db; stub them so the
@@ -23,6 +23,9 @@ function buildService(over: {
  resolvedShare?: unknown;
  page?: unknown;
  restricted?: boolean;
+  // #370 Stage B — the latest manual page-history row returned for the approved
+  // swap. `undefined` (the default) means the repo finds no manual version.
+  manualHistory?: unknown;
 } = {}) {
  const pageRepo = {
    findById: jest.fn(async () =>
@@ -34,6 +37,9 @@ function buildService(over: {
  const pagePermissionRepo = {
    hasRestrictedAncestor: jest.fn(async () => over.restricted ?? false),
  };
+  const pageHistoryRepo = {
+    findLatestByPageIdAndKind: jest.fn(async () => over.manualHistory ?? undefined),
+  };

  const service = new ShareService(
    {} as any, // shareRepo (unused on this path)
@@ -43,6 +49,7 @@ function buildService(over: {
    {} as any, // tokenService (unused)
    {} as any, // transclusionService (unused)
    {} as any, // workspaceRepo (unused)
+    pageHistoryRepo as any,
  );

  jest
@@ -53,7 +60,7 @@ function buildService(over: {
        : { id: SHARE, pageId: PAGE, spaceId: 'space-1' }) as any,
    );

-  return { service, pageRepo, pagePermissionRepo };
+  return { service, pageRepo, pagePermissionRepo, pageHistoryRepo };
 }

 describe('ShareService.resolveReadableSharePage (the share-access boundary)', () => {
@@ -133,4 +140,90 @@ describe('ShareService.resolveReadableSharePage (the share-access boundary)', ()
      includeCreator: true,
    });
  });
+
+  // #370 Stage B — "approved" publication freezes the served content/title to
+  // the latest manual page-history version, WITHOUT touching page.id or
+  // page.workspaceId (downstream attachment tokens are minted off those, so
+  // freezing them would mint tokens for the wrong owner).
+  describe('approved publication mode (content freeze)', () => {
+    const LIVE_PAGE = {
+      id: PAGE,
+      workspaceId: WS,
+      deletedAt: null,
+      title: 'Live draft title',
+      content: { type: 'doc', live: true },
+    };
+    const MANUAL = {
+      title: 'Saved version title',
+      content: { type: 'doc', saved: true },
+    };
+
+    it('swaps content + title to the latest manual version but PRESERVES id + workspaceId', async () => {
+      const { service, pageHistoryRepo } = buildService({
+        resolvedShare: {
+          id: SHARE,
+          pageId: PAGE,
+          spaceId: 'space-1',
+          publishedMode: 'approved',
+        },
+        page: { ...LIVE_PAGE },
+        manualHistory: MANUAL,
+      });
+
+      const out = await service.resolveReadableSharePage(SHARE, PAGE, WS);
+
+      expect(out).not.toBeNull();
+      // Content + title come from the saved version.
+      expect(out!.page.content).toEqual(MANUAL.content);
+      expect(out!.page.title).toBe(MANUAL.title);
+      // id + workspaceId stay LIVE (attachment-token ownership must not shift).
+      expect(out!.page.id).toBe(LIVE_PAGE.id);
+      expect(out!.page.workspaceId).toBe(LIVE_PAGE.workspaceId);
+      // Resolved against the LIVE page id and the manual tier, with content.
+      expect(pageHistoryRepo.findLatestByPageIdAndKind).toHaveBeenCalledWith(
+        LIVE_PAGE.id,
+        'manual',
+        { includeContent: true },
+      );
+    });
+
+    it('falls back to live content when no manual version exists yet', async () => {
+      const { service, pageHistoryRepo } = buildService({
+        resolvedShare: {
+          id: SHARE,
+          pageId: PAGE,
+          spaceId: 'space-1',
+          publishedMode: 'approved',
+        },
+        page: { ...LIVE_PAGE },
+        // manualHistory omitted → repo returns undefined
+      });
+
+      const out = await service.resolveReadableSharePage(SHARE, PAGE, WS);
+
+      expect(out).not.toBeNull();
+      expect(out!.page.content).toEqual(LIVE_PAGE.content);
+      expect(out!.page.title).toBe(LIVE_PAGE.title);
+      expect(pageHistoryRepo.findLatestByPageIdAndKind).toHaveBeenCalled();
+    });
+
+    it('does NOT consult page-history for a live share', async () => {
+      const { service, pageHistoryRepo } = buildService({
+        resolvedShare: {
+          id: SHARE,
+          pageId: PAGE,
+          spaceId: 'space-1',
+          publishedMode: 'live',
+        },
+        page: { ...LIVE_PAGE },
+        manualHistory: MANUAL,
+      });
+
+      const out = await service.resolveReadableSharePage(SHARE, PAGE, WS);
+
+      expect(out).not.toBeNull();
+      expect(out!.page.content).toEqual(LIVE_PAGE.content);
+      expect(pageHistoryRepo.findLatestByPageIdAndKind).not.toHaveBeenCalled();
+    });
+  });
 });
@@ -33,6 +33,7 @@ function buildService() {
    tokenService as any,
    {} as any, // transclusionService (unused)
    workspaceRepo as any,
+    {} as any, // pageHistoryRepo (unused on this path)
  );
 }

@@ -19,6 +19,7 @@ import {
 } from '../../common/helpers/prosemirror/utils';
 import { Node } from '@tiptap/pm/model';
 import { ShareRepo } from '@docmost/db/repos/share/share.repo';
+import { PageHistoryRepo } from '@docmost/db/repos/page/page-history.repo';
 import { PagePermissionRepo } from '@docmost/db/repos/page/page-permission.repo';
 import { updateAttachmentAttr } from './share.util';
 import { Page } from '@docmost/db/types/entity.types';
@@ -44,6 +45,7 @@ export class ShareService {
    private readonly tokenService: TokenService,
    private readonly transclusionService: TransclusionService,
    private readonly workspaceRepo: WorkspaceRepo,
+    private readonly pageHistoryRepo: PageHistoryRepo,
  ) {}

  /**
@@ -92,21 +94,39 @@ export class ShareService {
  }) {
    const { authUserId, workspaceId, page, createShareDto } = opts;

+    const includeSubPages = createShareDto.includeSubPages ?? false;
+    const publishedMode = createShareDto.publishedMode ?? 'live';
+
+    // #370 Stage B — 'approved' freezes a SINGLE page to its saved version; a
+    // sub-tree cannot be version-frozen in the MVP, so the two are mutually
+    // exclusive. Thrown before the try so the specific 400 reaches the client
+    // instead of being flattened to the generic "Failed to share page".
+    this.assertPublishedModeCompatible(publishedMode, includeSubPages);
+
    try {
      const shares = await this.shareRepo.findByPageId(page.id);
      if (shares) {
        return shares;
      }

-      return await this.shareRepo.insertShare({
+      const share = await this.shareRepo.insertShare({
        key: nanoIdGen().toLowerCase(),
        pageId: page.id,
-        includeSubPages: createShareDto.includeSubPages ?? false,
+        includeSubPages,
        searchIndexing: createShareDto.searchIndexing ?? false,
+        publishedMode,
        creatorId: authUserId,
        spaceId: page.spaceId,
        workspaceId,
      });
+
+      // Guarantee an approved share always has a saved version to serve: mint
+      // the first manual baseline from the page's current content on enable.
+      if (publishedMode === 'approved') {
+        await this.ensureApprovedBaseline(page.id);
+      }
+
+      return share;
    } catch (err) {
      this.logger.error(err);
      throw new BadRequestException('Failed to share page');
@@ -114,20 +134,84 @@ export class ShareService {
  }

  async updateShare(shareId: string, updateShareDto: UpdateShareDto) {
+    // Resolve the current share so the XOR gate can be evaluated against the
+    // EFFECTIVE post-update state (either field may be absent from the DTO).
+    const current = await this.shareRepo.findById(shareId);
+    if (!current) {
+      throw new NotFoundException('Share not found');
+    }
+
+    const effectiveIncludeSubPages =
+      updateShareDto.includeSubPages ?? current.includeSubPages ?? false;
+    const effectivePublishedMode = (updateShareDto.publishedMode ??
+      current.publishedMode ??
+      'live') as 'live' | 'approved';
+
+    // #370 Stage B — enforce the approved/includeSubPages XOR on the merged
+    // state. Thrown before the try so the specific 400 reaches the client.
+    this.assertPublishedModeCompatible(
+      effectivePublishedMode,
+      effectiveIncludeSubPages,
+    );
+
    try {
-      return this.shareRepo.updateShare(
+      const updated = await this.shareRepo.updateShare(
        {
          includeSubPages: updateShareDto.includeSubPages,
          searchIndexing: updateShareDto.searchIndexing,
+          publishedMode: updateShareDto.publishedMode,
        },
        shareId,
      );
+
+      // On (or while) enabling approved mode, ensure a manual baseline exists so
+      // public readers always have a saved version to serve. Idempotent: a no-op
+      // when the page already has a manual history row.
+      if (effectivePublishedMode === 'approved') {
+        await this.ensureApprovedBaseline(current.pageId);
+      }
+
+      return updated;
    } catch (err) {
      this.logger.error(err);
      throw new BadRequestException('Failed to update share');
    }
  }

+  /**
+   * #370 Stage B — 'approved' publication is mutually exclusive with
+   * includeSubPages: a whole sub-tree cannot be version-frozen in the MVP.
+   */
+  private assertPublishedModeCompatible(
+    publishedMode: 'live' | 'approved',
+    includeSubPages: boolean,
+  ): void {
+    if (publishedMode === 'approved' && includeSubPages) {
+      throw new BadRequestException(
+        'Approved publication cannot be combined with including sub-pages',
+      );
+    }
+  }
+
+  /**
+   * #370 Stage B — guarantee an approved share has a saved version to serve.
+   * When the page has NO manual history row yet, snapshot its CURRENT content as
+   * the first manual version. Idempotent: returns early when a manual version
+   * already exists, so it is safe to call on every approved update.
+   */
+  private async ensureApprovedBaseline(pageId: string): Promise<void> {
+    const existing = await this.pageHistoryRepo.findLatestByPageIdAndKind(
+      pageId,
+      'manual',
+    );
+    if (existing) return;
+
+    const page = await this.pageRepo.findById(pageId, { includeContent: true });
+    if (!page) return;
+
+    await this.pageHistoryRepo.saveHistory(page, { kind: 'manual' });
+  }
+
  /**
   * THE share access boundary in ONE place.
   *
@@ -173,7 +257,7 @@ export class ShareService {
    // passes no shareId (it resolved the share from the page itself).
    if (shareId != null && share.id !== shareId) return null;

-    const page = await this.pageRepo.findById(pageId, {
+    let page = await this.pageRepo.findById(pageId, {
      includeContent: true,
      includeCreator: opts?.includeCreator ?? false,
    });
@@ -185,6 +269,30 @@ export class ShareService {
      return null;
    }

+    // #370 Stage B — "approved" publication freezes what public readers see to
+    // the LAST manually-saved version (page_history.kind='manual'), not the live
+    // draft. This is the SINGLE canonical resolver every public read funnels
+    // through (the shared-page view, the SEO controller, AND the share
+    // assistant's page-read tool), so the swap here freezes ALL of them
+    // consistently — a public visitor and the assistant see the same bytes.
+    //
+    // Swap ONLY content + title. page.id and page.workspaceId stay LIVE on
+    // purpose: downstream updatePublicAttachments mints per-attachment tokens
+    // off page.id/workspaceId, so freezing those would mint tokens for the
+    // wrong owner. The SEO controller reads resolved.page.title, so the frozen
+    // title flows through automatically. If no manual version exists yet (rare —
+    // enabling an approved share auto-creates a baseline), fall back to live.
+    if (share.publishedMode === 'approved') {
+      const hist = await this.pageHistoryRepo.findLatestByPageIdAndKind(
+        page.id,
+        'manual',
+        { includeContent: true },
+      );
+      if (hist) {
+        page = { ...page, content: hist.content, title: hist.title };
+      }
+    }
+
    return { share, page };
  }

@@ -302,6 +410,7 @@ export class ShareService {
            'shares.key as shareKey',
            'shares.includeSubPages',
            'shares.searchIndexing',
+            'shares.publishedMode',
            'shares.creatorId',
            'shares.spaceId',
            'shares.workspaceId',
@@ -326,6 +435,7 @@ export class ShareService {
                  's.key as shareKey',
                  's.includeSubPages',
                  's.searchIndexing',
+                  's.publishedMode',
                  's.creatorId',
                  's.spaceId',
                  's.workspaceId',
@@ -355,6 +465,7 @@ export class ShareService {
      key: share.shareKey,
      includeSubPages: share.includeSubPages,
      searchIndexing: share.searchIndexing,
+      publishedMode: share.publishedMode,
      pageId: share.id,
      creatorId: share.creatorId,
      spaceId: share.spaceId,
@@ -32,6 +32,7 @@ import { TemplateRepo } from '@docmost/db/repos/template/template.repo';
 import { AiChatRepo } from '@docmost/db/repos/ai-chat/ai-chat.repo';
 import { AiChatMessageRepo } from '@docmost/db/repos/ai-chat/ai-chat-message.repo';
 import { AiChatRunRepo } from '@docmost/db/repos/ai-chat/ai-chat-run.repo';
+import { AiChatRunStepRepo } from '@docmost/db/repos/ai-chat/ai-chat-run-step.repo';
 import { AiChatPageSnapshotRepo } from '@docmost/db/repos/ai-chat/ai-chat-page-snapshot.repo';
 import { AiProviderCredentialsRepo } from '@docmost/db/repos/ai-chat/ai-provider-credentials.repo';
 import { AiMcpServerRepo } from '@docmost/db/repos/ai-chat/ai-mcp-server.repo';
@@ -125,6 +126,7 @@ import { firstSqlToken } from '../integrations/metrics/metrics.constants';
    AiChatRepo,
    AiChatMessageRepo,
    AiChatRunRepo,
+    AiChatRunStepRepo,
    AiChatPageSnapshotRepo,
    AiProviderCredentialsRepo,
    AiMcpServerRepo,
@@ -161,6 +163,7 @@ import { firstSqlToken } from '../integrations/metrics/metrics.constants';
    AiChatRepo,
    AiChatMessageRepo,
    AiChatRunRepo,
+    AiChatRunStepRepo,
    AiChatPageSnapshotRepo,
    AiProviderCredentialsRepo,
    AiMcpServerRepo,
@@ -0,0 +1,242 @@
+import { type Kysely, sql } from 'kysely';
+
+/**
+ * #529 Phase A1 — the `ru_en` text-search configuration + the config swap.
+ *
+ * WHY: the search stack was pinned to the `english` FTS config, which stems only
+ * Latin words. On a Russian-language wiki that is a morphology black hole:
+ * «ресторанов москвы» never matched a page titled «ресторан в москве». `ru_en`
+ * layers the russian_stem over the Cyrillic token classes and english_stem over
+ * the ascii ones, so BOTH languages get proper morphology from one config.
+ *
+ *   CREATE TEXT SEARCH CONFIGURATION ru_en (COPY = simple);
+ *   ALTER ... asciiword/asciihword/hword_asciipart WITH english_stem;
+ *   ALTER ... word/hword/hword_part           WITH russian_stem;
+ *
+ * `to_tsvector('ru_en', …)` with the LITERAL config name is IMMUTABLE, so it is
+ * valid inside a trigger, a generated column and an index expression.
+ *
+ * THE INVARIANT (acceptance #13): the config of the STORED column and the config
+ * of the QUERY must change together. This migration flips BOTH stored sides
+ * (pages.tsv via its trigger + a reindex; page_embeddings.fts, the RAG lexical
+ * leg, via its generated expression); the matching QUERY-side flips
+ * (search.service.ts and page-embedding.repo.ts `hybridSearch`) ship in the SAME
+ * commit. Trigram indexes are LOWER(f_unaccent(...)) and do NOT depend on the FTS
+ * config, so they are untouched.
+ *
+ * REINDEX / LOCK MODEL (deploy-critical). Kysely runs EACH migration in its OWN
+ * transaction (see sibling 20260706T120000 "Kysely runs each migration in a
+ * transaction"; migrate.ts / migration.service.ts set no `disableTransactions`,
+ * and PostgresJSDialect has transactional DDL). A single migration file therefore
+ * cannot commit between batches, so the issue's "procedural batch job OUTSIDE the
+ * transaction + dual-config read window + migration_complete gate" is not
+ * expressible in-migration here. That machinery bridges a reindex spread over
+ * MANY committed batches, during which some rows are still `english` while others
+ * are already `ru_en`. Our pages.tsv reindex is a SINGLE `UPDATE pages SET tsv`,
+ * ATOMIC within THIS migration's own transaction: at COMMIT every row is `ru_en`
+ * at once, so no morphology-desync window exists and no dual-config read path is
+ * required — the query config flips to `ru_en` in the very same release. This is
+ * the deliberate, correct adaptation to this framework (see the PR notes).
+ *
+ *   - pages.tsv: swapping the trigger is a cheap catalog change (no table lock),
+ *     and the reindex is a single `UPDATE pages SET tsv = <ru_en expr>` — a
+ *     ROW-level-lock (RowExclusiveLock) backfill, NOT an ACCESS EXCLUSIVE rewrite
+ *     (mirrors the existing space_id backfill in 20250725T052004). On a LARGE
+ *     tenant this still writes every row + its WAL and leaves dead tuples, so it
+ *     can take MINUTES and blocks the startup migrator for that time — but it
+ *     never blocks concurrent reads. It stays inline unconditionally.
+ *
+ *   - page_embeddings.fts is a GENERATED STORED column; Postgres cannot change a
+ *     generated expression without DROP+ADD, which is a full-table ACCESS
+ *     EXCLUSIVE REWRITE of page_embeddings — it blocks ALL reads AND writes on
+ *     that table (including the RAG agent) for the rewrite's duration. That inline
+ *     rewrite is appropriate for small/typical tenants (this fork's target) and
+ *     is the DEFAULT.
+ *
+ *     LARGE TENANTS have two documented escape hatches, either of which makes the
+ *     migration genuinely no-op the rewrite (it is NOT a blind DROP+ADD):
+ *       (a) Set `SEARCH_EMBEDDINGS_FTS_INLINE_REWRITE=false`. The migration then
+ *           SKIPS the embeddings rewrite entirely and logs a WARNING. The operator
+ *           MUST perform the ru_en fts swap out-of-band; until they do, the RAG
+ *           lexical leg stays on `english` while the query config is `ru_en` — a
+ *           documented, operator-owned desync window. (pages.tsv still swaps
+ *           inline — the gate is ONLY the embeddings rewrite.)
+ *       (b) Perform the swap out-of-band BEFORE deploy — add a plain column →
+ *           batched backfill → brief-lock swap → CREATE INDEX CONCURRENTLY — so
+ *           the `fts` column's generated expression already references the TARGET
+ *           config when the migration runs. The migration detects this (it reads
+ *           the column's actual generation expression from pg_catalog) and does a
+ *           TRUE no-op — no DROP, no ADD, no rewrite. This is real idempotency,
+ *           not the old (false) "IF-EXISTS guards no-op" claim: `DROP COLUMN IF
+ *           EXISTS` guards against ABSENCE, not presence, so it would have dropped
+ *           and recreated an existing `fts` regardless. The at-target check is the
+ *           only honest no-op path.
+ *
+ * Same documented trade-off family as the #443 trgm GIN migration (20260706T120000).
+ */
+
+// pages.tsv trigger body for a given FTS config — mirrors the latest form
+// (20250729T213756): f_unaccent + a 1MB text cap on text_content, weights A/B.
+function pagesTriggerSql(config: 'ru_en' | 'english') {
+  return sql`
+    CREATE OR REPLACE FUNCTION pages_tsvector_trigger() RETURNS trigger AS $$
+    begin
+        new.tsv :=
+                  setweight(to_tsvector('${sql.raw(config)}', f_unaccent(coalesce(new.title, ''))), 'A') ||
+                  setweight(to_tsvector('${sql.raw(config)}', f_unaccent(substring(coalesce(new.text_content, ''), 1, 1000000))), 'B');
+        return new;
+    end;
+    $$ LANGUAGE plpgsql;
+  `;
+}
+
+async function swapPagesConfig(db: Kysely<any>, config: 'ru_en' | 'english') {
+  // 1. Point the trigger at the target config (new/edited rows use it going
+  //    forward). CREATE OR REPLACE FUNCTION takes only a brief catalog lock.
+  await pagesTriggerSql(config).execute(db);
+
+  // 2. Reindex existing rows: recompute tsv directly with the target config. A
+  //    plain UPDATE — row locks, no ACCESS EXCLUSIVE. Equivalent to firing the
+  //    trigger but cheaper (no self-update round trip).
+  await sql`
+    UPDATE pages
+    SET tsv =
+        setweight(to_tsvector('${sql.raw(config)}', f_unaccent(coalesce(title, ''))), 'A') ||
+        setweight(to_tsvector('${sql.raw(config)}', f_unaccent(substring(coalesce(text_content, ''), 1, 1000000))), 'B')
+  `.execute(db);
+}
+
+// The default in-migration ACCESS EXCLUSIVE rewrite of page_embeddings.fts is
+// ON unless the operator explicitly opts out with the env flag. Parsed strictly
+// (mirrors CLIENT_TELEMETRY_ENABLED / DEBUG_MODE in common/): only a literal
+// (case-insensitive) 'false' disables it; anything else — unset included —
+// keeps the default true.
+function inlineEmbeddingsRewriteEnabled(): boolean {
+  return (
+    (process.env.SEARCH_EMBEDDINGS_FTS_INLINE_REWRITE ?? 'true').toLowerCase() !==
+    'false'
+  );
+}
+
+// Read page_embeddings.fts's ACTUAL generated-column expression from pg_catalog
+// (the generation expression is stored as a column default marked generated).
+// Returns '' when the column is absent.
+async function embeddingsFtsExpr(db: Kysely<any>): Promise<string> {
+  const r = await sql<{ def: string }>`
+    SELECT pg_get_expr(d.adbin, d.adrelid) AS def
+    FROM pg_attrdef d
+    JOIN pg_attribute a ON a.attrelid = d.adrelid AND a.attnum = d.adnum
+    WHERE a.attname = 'fts'
+      AND a.attrelid = 'page_embeddings'::regclass
+      AND NOT a.attisdropped
+  `.execute(db);
+  return r.rows[0]?.def ?? '';
+}
+
+async function swapEmbeddingsFtsConfig(
+  db: Kysely<any>,
+  config: 'ru_en' | 'english',
+) {
+  // 1. TRUE no-op path (real out-of-band escape hatch): if the column's current
+  //    generation expression already references the TARGET config, there is
+  //    nothing to do. An operator who pre-swapped the column out-of-band lands
+  //    here and the migration does NOT rewrite the table. ('ru_en' and 'english'
+  //    are disjoint tokens, neither a substring of the other or of the rest of
+  //    the expression, so a plain contains-check is unambiguous.)
+  const currentExpr = await embeddingsFtsExpr(db);
+  if (currentExpr.includes(config)) return;
+
+  // 2. Env-gated opt-out: large tenants set SEARCH_EMBEDDINGS_FTS_INLINE_REWRITE
+  //    =false to skip the ACCESS EXCLUSIVE rewrite in-migration and own the swap
+  //    out-of-band. Warn loudly so the desync window is not silent.
+  if (!inlineEmbeddingsRewriteEnabled()) {
+    // eslint-disable-next-line no-console
+    console.warn(
+      `[migration 20260707T130000] SEARCH_EMBEDDINGS_FTS_INLINE_REWRITE=false: ` +
+        `SKIPPING the page_embeddings.fts rewrite to '${config}'. The operator MUST ` +
+        `perform this fts swap out-of-band. Until then the RAG lexical leg stays on ` +
+        `its current config while the query config is '${config}' (documented, ` +
+        `operator-owned desync window).`,
+    );
+    return;
+  }
+
+  // 3. Default inline path: the generated `fts` expression can only change via
+  //    DROP+ADD (a full-table ACCESS EXCLUSIVE rewrite; see the lock note in the
+  //    header). The GIN index depends on the column, so it is dropped with it and
+  //    recreated.
+  await sql`DROP INDEX IF EXISTS idx_page_embeddings_fts`.execute(db);
+  await sql`ALTER TABLE page_embeddings DROP COLUMN IF EXISTS fts`.execute(db);
+  await sql`
+    ALTER TABLE page_embeddings
+      ADD COLUMN fts tsvector
+      GENERATED ALWAYS AS (to_tsvector('${sql.raw(config)}', f_unaccent(content))) STORED
+  `.execute(db);
+  await sql`
+    CREATE INDEX IF NOT EXISTS idx_page_embeddings_fts
+      ON page_embeddings USING gin(fts)
+  `.execute(db);
+}
+
+async function ruEnConfigExists(db: Kysely<any>): Promise<boolean> {
+  const r = await sql<{ n: number }>`
+    SELECT count(*)::int AS n FROM pg_ts_config WHERE cfgname = 'ru_en'
+  `.execute(db);
+  return (r.rows[0]?.n ?? 0) > 0;
+}
+
+async function ensureRuEnConfig(db: Kysely<any>): Promise<void> {
+  // Idempotent by EXISTENCE, not by drop-recreate. The old `DROP ... IF EXISTS;
+  // CREATE` was safe only on a first run: on a re-run the page_embeddings.fts
+  // generated column already has a hard dependency on ru_en, so dropping the
+  // config would fail. Create only when it is genuinely missing.
+  if (await ruEnConfigExists(db)) return;
+  await sql`CREATE TEXT SEARCH CONFIGURATION ru_en (COPY = simple)`.execute(db);
+  // Latin token classes → english_stem.
+  await sql`
+    ALTER TEXT SEARCH CONFIGURATION ru_en
+      ALTER MAPPING FOR asciiword, asciihword, hword_asciipart
+      WITH english_stem
+  `.execute(db);
+  // Cyrillic / non-ascii token classes → russian_stem.
+  await sql`
+    ALTER TEXT SEARCH CONFIGURATION ru_en
+      ALTER MAPPING FOR word, hword, hword_part
+      WITH russian_stem
+  `.execute(db);
+}
+
+export async function up(db: Kysely<any>): Promise<void> {
+  await ensureRuEnConfig(db);
+
+  // Flip both stored sides to ru_en (query-side flips in the same commit).
+  // swapEmbeddingsFtsConfig no-ops when fts already references ru_en, so a
+  // re-run of up() is idempotent and does NOT re-rewrite the embeddings table.
+  await swapPagesConfig(db, 'ru_en');
+  await swapEmbeddingsFtsConfig(db, 'ru_en');
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  // Reverse ORDER matters: the trigger and the generated column reference the
+  // `ru_en` config by name, so they must be moved back to `english` BEFORE the
+  // config can be dropped (a generated column that still depends on `ru_en` would
+  // block the DROP with a dependency error).
+  await swapEmbeddingsFtsConfig(db, 'english');
+  await swapPagesConfig(db, 'english');
+
+  // Drop the config ONLY if nothing still references it. When the embeddings
+  // rewrite was gated off (SEARCH_EMBEDDINGS_FTS_INLINE_REWRITE=false), the fts
+  // column can still reference ru_en — dropping the config would then fail with a
+  // dependency error. Skip + warn so down() stays non-fatal; the operator drops
+  // ru_en after completing the out-of-band english swap.
+  if ((await embeddingsFtsExpr(db)).includes('ru_en')) {
+    // eslint-disable-next-line no-console
+    console.warn(
+      `[migration 20260707T130000] down(): page_embeddings.fts still references ` +
+        `ru_en (inline rewrite was gated off) — leaving the ru_en text-search ` +
+        `configuration in place. Drop it out-of-band once fts is back on 'english'.`,
+    );
+    return;
+  }
+  await sql`DROP TEXT SEARCH CONFIGURATION IF EXISTS ru_en`.execute(db);
+}
@@ -0,0 +1,70 @@
+import { type Kysely, sql } from 'kysely';
+
+/**
+ * `ai_chat_run_steps` — append-only per-step persistence for an assistant turn
+ * (#492 wave C). Each finished agent step's UI `parts` (its text part + a part
+ * per tool call, WITH the tool output) is INSERTed as its own lightweight row the
+ * moment the step ends, instead of REWRITING the whole assistant row's growing
+ * `metadata.parts` jsonb on every `onStepFinish`.
+ *
+ * WHY a separate table + INSERT (not a jsonb `||` append on the message row): a
+ * Postgres jsonb UPDATE rewrites the ENTIRE TOASTed row version under MVCC, so
+ * re-persisting a growing `metadata.parts` on every step is O(n²) write volume
+ * (a 50-step run with ~100 KB tool outputs wrote hundreds of MB of WAL / dead
+ * tuples per turn, hammering autovacuum). `||` would only shave the network
+ * payload — the WAL/TOAST rewrite harm remains. An INSERT into a per-step table
+ * writes ONLY that step's bytes, so the per-turn write volume is O(Σ steps).
+ *
+ * The full `metadata.parts` on the message row is assembled ONCE at finalize (the
+ * terminal completed/error/aborted write). Mid-run, a resuming client's seed is
+ * reconstructed by concatenating these step rows in `step_index` order — which
+ * reproduces exactly what the old per-step full-row rewrite persisted. Records
+ * written the OLD way (full `metadata.parts` on the row, no step rows) still
+ * reconstruct from the row unchanged; the two eras are distinguished by whether
+ * the row already carries non-empty `metadata.parts` (see reconstructRunParts /
+ * assembleStepParts in ai-chat.service.ts).
+ *
+ * ON DELETE CASCADE on `message_id`: the step rows are a derived projection of the
+ * assistant message; they must vanish with it (or with its workspace).
+ */
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .createTable('ai_chat_run_steps')
+    .ifNotExists()
+    .addColumn('id', 'uuid', (col) =>
+      col.primaryKey().defaultTo(sql`gen_uuid_v7()`),
+    )
+    // The assistant message row this step belongs to (the #183 projection). The
+    // step rows are a derived, per-step slice of that message, so they cascade.
+    .addColumn('message_id', 'uuid', (col) =>
+      col.references('ai_chat_messages.id').onDelete('cascade').notNull(),
+    )
+    .addColumn('workspace_id', 'uuid', (col) =>
+      col.references('workspaces.id').onDelete('cascade').notNull(),
+    )
+    // 0-based index of the finished step within the turn. Ordering key for
+    // reconstruction; unique per message (idempotent step re-persist).
+    .addColumn('step_index', 'integer', (col) => col.notNull())
+    // The step's UI parts (text part + a `tool-*` part per call, WITH output).
+    // Concatenated in step order to rebuild the turn's `metadata.parts`.
+    .addColumn('parts', 'jsonb', (col) => col.notNull())
+    .addColumn('created_at', 'timestamptz', (col) =>
+      col.notNull().defaultTo(sql`now()`),
+    )
+    .execute();
+
+  // Idempotent per-step persist: a retried INSERT of the same (message, step)
+  // is a no-op (the service uses ON CONFLICT DO NOTHING). This also serves the
+  // reconstruction read (WHERE message_id ORDER BY step_index).
+  await db.schema
+    .createIndex('ai_chat_run_steps_message_step_uidx')
+    .ifNotExists()
+    .on('ai_chat_run_steps')
+    .columns(['message_id', 'step_index'])
+    .unique()
+    .execute();
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema.dropTable('ai_chat_run_steps').ifExists().execute();
+}
@@ -0,0 +1,29 @@
+import { type Kysely, sql } from 'kysely';
+
+/**
+ * #370 Stage B — share "approved" (publish-only-the-saved-version) mode.
+ *
+ * Adds `shares.published_mode`, the per-share switch between:
+ *   - 'live'     — public readers see the current draft (legacy behavior)
+ *   - 'approved' — public readers see the LAST manually-saved version
+ *                  (page_history.kind='manual'), not the live draft
+ *
+ * NOT NULL with a 'live' default so every existing share keeps its current
+ * (live) semantics with no data backfill. Standalone + single-concern +
+ * additive per the #363 crash-loop rule — no coupled baseline write here;
+ * the first manual baseline is minted by the service on enable, not by this
+ * migration. Stored as a short varchar to stay forward-compatible without an
+ * enum migration.
+ */
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .alterTable('shares')
+    .addColumn('published_mode', 'varchar(20)', (col) =>
+      col.notNull().defaultTo(sql`'live'`),
+    )
+    .execute();
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema.alterTable('shares').dropColumn('published_mode').execute();
+}
@@ -0,0 +1,95 @@
+import { Injectable } from '@nestjs/common';
+import { InjectKysely } from 'nestjs-kysely';
+import { KyselyDB, KyselyTransaction } from '../../types/kysely.types';
+import { dbOrTx } from '../../utils';
+import { AiChatRunStep } from '@docmost/db/types/entity.types';
+
+/**
+ * Append-only per-step persistence for an assistant turn (#492). Each finished
+ * agent step's UI `parts` (its text part + a `tool-*` part per call, WITH the
+ * tool output) is INSERTed as its own lightweight row the moment the step ends —
+ * instead of REWRITING the assistant row's growing `metadata.parts` jsonb on every
+ * `onStepFinish` (a Postgres jsonb UPDATE rewrites the whole TOASTed row version
+ * under MVCC, so that was O(n²) WAL/dead-tuple churn per turn).
+ *
+ * The full `metadata.parts` on the message row is assembled ONCE at finalize;
+ * mid-run, a resuming client's seed is rebuilt from these rows in `stepIndex`
+ * order (see `assembleStepParts` / the reconstruct seam in ai-chat.service.ts).
+ * Every method is workspace-scoped as defense-in-depth.
+ */
+@Injectable()
+export class AiChatRunStepRepo {
+  constructor(@InjectKysely() private readonly db: KyselyDB) {}
+
+  /**
+   * Append one finished step's parts. Idempotent: a retried persist of the SAME
+   * (message, stepIndex) is a no-op via ON CONFLICT DO NOTHING — the per-step
+   * writes are fired fire-and-forget + serialized, and a duplicate must never
+   * throw into the stream or double the parts. Returns whether a NEW row landed
+   * (false = the step was already persisted).
+   */
+  async insertStep(
+    messageId: string,
+    workspaceId: string,
+    stepIndex: number,
+    parts: unknown,
+    trx?: KyselyTransaction,
+  ): Promise<boolean> {
+    const db = dbOrTx(this.db, trx);
+    const inserted = await db
+      .insertInto('aiChatRunSteps')
+      .values({
+        messageId,
+        workspaceId,
+        stepIndex,
+        // jsonb column: cast through never (same pattern as the message repo).
+        parts: parts as never,
+      })
+      .onConflict((oc) => oc.columns(['messageId', 'stepIndex']).doNothing())
+      .returning('id')
+      .executeTakeFirst();
+    return inserted !== undefined;
+  }
+
+  /** All persisted steps for ONE assistant message, in step order. */
+  async findByMessage(
+    messageId: string,
+    workspaceId: string,
+  ): Promise<AiChatRunStep[]> {
+    return this.db
+      .selectFrom('aiChatRunSteps')
+      .selectAll('aiChatRunSteps')
+      .where('messageId', '=', messageId)
+      .where('workspaceId', '=', workspaceId)
+      .orderBy('stepIndex', 'asc')
+      .execute();
+  }
+
+  /**
+   * All persisted steps for a SET of assistant messages, grouped by messageId
+   * (each group in step order). One query for the batch — the hydration seam
+   * (getMessages / delta / export) calls this only for the rows that actually
+   * need reconstruction (an active new-style row whose `metadata.parts` is still
+   * empty), which is usually none, so this is skipped on the common path.
+   */
+  async findByMessageIds(
+    messageIds: string[],
+    workspaceId: string,
+  ): Promise<Map<string, AiChatRunStep[]>> {
+    const byMessage = new Map<string, AiChatRunStep[]>();
+    if (messageIds.length === 0) return byMessage;
+    const rows = await this.db
+      .selectFrom('aiChatRunSteps')
+      .selectAll('aiChatRunSteps')
+      .where('messageId', 'in', messageIds)
+      .where('workspaceId', '=', workspaceId)
+      .orderBy('stepIndex', 'asc')
+      .execute();
+    for (const row of rows) {
+      const list = byMessage.get(row.messageId);
+      if (list) list.push(row);
+      else byMessage.set(row.messageId, [row]);
+    }
+    return byMessage;
+  }
+}
@@ -200,8 +200,11 @@ export class PageEmbeddingRepo {
   *
   * The `model_dimensions = $dim` filter applies ONLY on the semantic side
   * (cosine compares same-dimension vectors; pgvector errors otherwise). The
-   * lexical side (`fts`) is dimension-independent. If `websearch_to_tsquery`
-   * yields an EMPTY query (e.g. the text is all stopwords) the `@@` matches
+   * lexical side (`fts`) is dimension-independent. Its query config is `ru_en`,
+   * matched IN LOCKSTEP with the `page_embeddings.fts` generated column's config
+   * (#529 acceptance #13): a mismatch silently breaks Cyrillic RAG retrieval. If
+   * `websearch_to_tsquery` yields an EMPTY query (e.g. the text is all stopwords)
+   * the `@@` matches
   * nothing and the lexical CTE is empty, so results degrade to pure-semantic —
   * which is correct behaviour, not an error.
   *
@@ -249,7 +252,7 @@ export class PageEmbeddingRepo {
               row_number() OVER (ORDER BY ts_rank(pe.fts, q.query) DESC) AS rank_ix
        FROM page_embeddings pe
        JOIN pages p ON p.id = pe.page_id,
-             websearch_to_tsquery('english', f_unaccent(${queryText})) AS q(query)
+             websearch_to_tsquery('ru_en', f_unaccent(${queryText})) AS q(query)
        WHERE pe.workspace_id = ${workspaceId}
          AND pe.space_id IN (${spaceList})
          AND p.deleted_at IS NULL
@@ -157,6 +157,44 @@ export class PageHistoryRepo {
    return { ...result, items: result.items.map(attachPageHistoryAgent) };
  }

+  /**
+   * #395 — cheap projection of a page's FULL history timeline for the work-time
+   * estimate: only the columns the sessionizer needs, no heavy `content`, sorted
+   * oldest→newest. The secondary `id` tie-break keeps rows sharing a `createdAt`
+   * (e.g. a synchronous pre-agent boundary row + the immediate agent snapshot)
+   * in a deterministic order.
+   */
+  async findTimelineByPageId(
+    pageId: string,
+    trx?: KyselyTransaction,
+  ): Promise<
+    Array<
+      Pick<
+        PageHistory,
+        | 'createdAt'
+        | 'lastUpdatedById'
+        | 'lastUpdatedSource'
+        | 'lastUpdatedAiChatId'
+        | 'kind'
+      >
+    >
+  > {
+    const db = dbOrTx(this.db, trx);
+    return db
+      .selectFrom('pageHistory')
+      .select([
+        'createdAt',
+        'lastUpdatedById',
+        'lastUpdatedSource',
+        'lastUpdatedAiChatId',
+        'kind',
+      ])
+      .where('pageId', '=', pageId)
+      .orderBy('createdAt', 'asc')
+      .orderBy('id', 'asc')
+      .execute();
+  }
+
  async findPageLastHistory(
    pageId: string,
    opts?: {
@@ -181,6 +219,36 @@ export class PageHistoryRepo {
      .executeTakeFirst();
  }

+  /**
+   * #370 Stage B — resolve the latest snapshot of a page at a given
+   * intentionality tier. Used by the "approved" share mode to serve the last
+   * manually-saved version (`kind='manual'`) to public readers instead of the
+   * live draft. Modeled on `findPageLastHistory` with an added `kind` filter and
+   * the same deterministic `(createdAt desc, id desc)` tie-break, so two rows
+   * sharing a createdAt still resolve to a single stable "latest".
+   */
+  async findLatestByPageIdAndKind(
+    pageId: string,
+    kind: PageHistoryKind,
+    opts?: {
+      includeContent?: boolean;
+      trx?: KyselyTransaction;
+    },
+  ) {
+    const db = dbOrTx(this.db, opts?.trx);
+
+    return await db
+      .selectFrom('pageHistory')
+      .select(this.baseFields)
+      .$if(opts?.includeContent, (qb) => qb.select('content'))
+      .where('pageId', '=', pageId)
+      .where('kind', '=', kind)
+      .limit(1)
+      .orderBy('createdAt', 'desc')
+      .orderBy('id', 'desc')
+      .executeTakeFirst();
+  }
+
  withLastUpdatedBy(eb: ExpressionBuilder<DB, 'pageHistory'>) {
    return jsonObjectFrom(
      eb
@@ -28,6 +28,7 @@ export class ShareRepo {
    'pageId',
    'includeSubPages',
    'searchIndexing',
+    'publishedMode',
    'creatorId',
    'spaceId',
    'workspaceId',
@@ -340,6 +340,7 @@ export interface Shares {
  includeSubPages: Generated<boolean | null>;
  key: string;
  pageId: string | null;
+  publishedMode: Generated<string>;
  searchIndexing: Generated<boolean | null>;
  spaceId: string;
  updatedAt: Generated<Timestamp>;
@@ -692,6 +693,22 @@ export interface AiChatRuns {
  updatedAt: Generated<Timestamp>;
 }

+// Append-only per-step persistence for an assistant turn (#492). Mirrors
+// migration 20260708T120000-ai-chat-run-steps.ts. Each finished agent step's UI
+// `parts` are INSERTed as their own row (instead of rewriting the message row's
+// growing `metadata.parts` jsonb every step — an O(n²) WAL/TOAST churn). The full
+// `metadata.parts` is assembled once at finalize; mid-run a resuming client's seed
+// is rebuilt by concatenating these rows in `stepIndex` order. Cascades with the
+// assistant message row it projects.
+export interface AiChatRunSteps {
+  id: Generated<string>;
+  messageId: string;
+  workspaceId: string;
+  stepIndex: number;
+  parts: Json;
+  createdAt: Generated<Timestamp>;
+}
+
 // Per-(chat,page) snapshot of the open page's Markdown at the END of the agent's
 // previous turn (#274). Mirrors migration 20260702T120000-ai-chat-page-snapshot.ts.
 // The next turn diffs the CURRENT Markdown against `contentMd` to surface edits a
@@ -729,6 +746,7 @@ export interface DB {
  aiChats: AiChats;
  aiChatMessages: AiChatMessages;
  aiChatRuns: AiChatRuns;
+  aiChatRunSteps: AiChatRunSteps;
  aiChatPageSnapshots: AiChatPageSnapshots;
  apiKeys: ApiKeys;
  attachments: Attachments;
@@ -4,6 +4,7 @@ import {
  AiChats,
  AiChatMessages,
  AiChatRuns,
+  AiChatRunSteps,
  AiChatPageSnapshots,
  Attachments,
  Comments,
@@ -64,6 +65,12 @@ export type InsertableAiChatMessage = Omit<Insertable<AiChatMessages>, 'tsv'>;
 export type AiChatRun = Selectable<AiChatRuns>;
 export type InsertableAiChatRun = Insertable<AiChatRuns>;

+// AI Chat Run Step (#492): append-only per-step parts persistence. Each finished
+// agent step's UI parts are stored as their own row; the full turn's parts are
+// assembled from these (in stepIndex order) for a mid-run resume seed.
+export type AiChatRunStep = Selectable<AiChatRunSteps>;
+export type InsertableAiChatRunStep = Insertable<AiChatRunSteps>;
+
 // AI Chat Page Snapshot (#274): per-(chat,page) Markdown snapshot taken at the
 // end of the agent's previous turn, diffed against the current page next turn to
 // detect human edits made between turns.
@@ -85,6 +85,14 @@ export class ImportController {
      throw new BadRequestException('spaceId is required');
    }

+    // #502: optional multipart field. Only the MCP agent `createPage` path sends
+    // `disableMarkdownExtensions=true` (its body is agent-authored plain prose /
+    // config, so a `$…$` span must stay literal and a bare `www.host` must not
+    // autolink). A HUMAN file upload omits the field, so it stays false and math
+    // + autolink remain ON for human imports. Settable ONLY via this API param.
+    const disableMarkdownExtensions =
+      file.fields?.disableMarkdownExtensions?.value === 'true';
+
    const ability = await this.spaceAbility.createForUser(user, spaceId);
    if (ability.cannot(SpaceCaslAction.Edit, SpaceCaslSubject.Page)) {
      throw new ForbiddenException();
@@ -95,6 +103,7 @@ export class ImportController {
      user.id,
      spaceId,
      workspace.id,
+      disableMarkdownExtensions,
    );

    const ext = path.extname(file.filename).toLowerCase();
@@ -0,0 +1,131 @@
+// p-limit and @sindresorhus/slugify are ESM-only and not in jest's transform
+// allowlist; both are irrelevant to createDrawioSvg (a pure fs + string method),
+// so they are mocked out to keep the module graph loadable under ts-jest.
+jest.mock('p-limit', () => ({
+  __esModule: true,
+  default: () => (fn: () => unknown) => fn(),
+}));
+jest.mock('@sindresorhus/slugify', () => ({
+  __esModule: true,
+  default: (input: string) => String(input),
+}));
+
+import { promises as fs } from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+import { ImportAttachmentService } from './import-attachment.service';
+
+/**
+ * Unit test for ImportAttachmentService.createDrawioSvg (issue #507).
+ *
+ * The Confluence import wraps a `.drawio` file into a `.drawio.svg` attachment.
+ * The `content=` payload MUST be the mxfile XML entity-escaped (draw.io's native
+ * form), NOT base64 — draw.io's editor decodes a base64 content= via Latin-1
+ * atob, mangling every non-ASCII char into mojibake. createDrawioSvg touches no
+ * injected dependency, so the service is built with placeholder deps.
+ */
+describe('ImportAttachmentService.createDrawioSvg (#507)', () => {
+  const service = new ImportAttachmentService(
+    {} as any,
+    {} as any,
+    {} as any,
+  );
+  const call = (p: string): Promise<Buffer> =>
+    (service as any).createDrawioSvg(p);
+
+  let tmpDir: string;
+  beforeAll(async () => {
+    tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'drawio-507-'));
+  });
+  afterAll(async () => {
+    await fs.rm(tmpDir, { recursive: true, force: true });
+  });
+
+  const writeDrawio = async (name: string, xml: string): Promise<string> => {
+    const p = path.join(tmpDir, name);
+    await fs.writeFile(p, xml, 'utf-8');
+    return p;
+  };
+
+  it('writes content= as entity-encoded XML, not base64', async () => {
+    const drawio =
+      '<mxfile host="Confluence"><diagram name="Схема — ёж">' +
+      '<mxGraphModel><root><mxCell id="0"/>' +
+      '<mxCell id="2" value="Старт-бит" vertex="1" parent="0"/>' +
+      '</root></mxGraphModel></diagram></mxfile>';
+    const p = await writeDrawio('cyrillic.drawio', drawio);
+
+    const svg = (await call(p)).toString('utf-8');
+    const content = /content="([^"]*)"/.exec(svg)?.[1];
+    expect(content).toBeDefined();
+
+    // Entity-encoded XML form, starting with &lt;mxfile — never a base64 blob.
+    expect(content).toMatch(/^&lt;mxfile/);
+    expect(content).toContain('&lt;');
+    // Non-ASCII survives as raw UTF-8, with no Latin-1 mojibake.
+    expect(content).toContain('Старт-бит');
+    expect(content).toContain('Схема — ёж');
+    expect(content).not.toContain('Ð');
+
+    // Decoding the attribute (un-escaping) yields the original drawio file.
+    const decoded = content!
+      .replace(/&lt;/g, '<')
+      .replace(/&gt;/g, '>')
+      .replace(/&quot;/g, '"')
+      .replace(/&amp;/g, '&');
+    expect(decoded).toBe(drawio);
+  });
+
+  it('encodes literal tab/newline/CR as numeric char-refs, not literal control chars (#507 F1)', async () => {
+    // A literal tab/newline/CR inside the mxfile XML would be collapsed to a
+    // single space by XML attribute-value normalization when the draw.io editor
+    // reads content=, silently flattening multi-line labels and tab-bearing
+    // values. They must be emitted as numeric char-refs instead.
+    const drawio =
+      '<mxfile><diagram name="p">' +
+      '<mxGraphModel><root><mxCell id="0"/>' +
+      '<mxCell id="2" value="col1\tcol2" style="html=1;\nshadow=0" vertex="1" parent="0"/>' +
+      '<mxCell id="3" value="Line1\nLine2\rLine3" vertex="1" parent="0"/>' +
+      '</root></mxGraphModel></diagram></mxfile>';
+    const p = await writeDrawio('ctrl.drawio', drawio);
+
+    const svg = (await call(p)).toString('utf-8');
+    const content = /content="([^"]*)"/.exec(svg)?.[1];
+    expect(content).toBeDefined();
+    // No literal control chars survive in the attribute value.
+    expect(content).not.toMatch(/[\t\n\r]/);
+    // They round-trip as numeric char-refs.
+    expect(content).toContain('&#x9;');
+    expect(content).toContain('&#xa;');
+    expect(content).toContain('&#xd;');
+    // Decoding (char-refs back to literal, entities back) recovers the file.
+    const decoded = content!
+      .replace(/&lt;/g, '<')
+      .replace(/&gt;/g, '>')
+      .replace(/&quot;/g, '"')
+      .replace(/&#39;/g, "'")
+      .replace(/&#x9;/gi, '\t')
+      .replace(/&#xa;/gi, '\n')
+      .replace(/&#xd;/gi, '\r')
+      .replace(/&amp;/g, '&');
+    expect(decoded).toBe(drawio);
+  });
+
+  it('escapes XML metacharacters in the drawio payload', async () => {
+    const drawio = '<mxfile><diagram name="a &amp; b">"q" &lt;x&gt;</diagram></mxfile>';
+    const p = await writeDrawio('meta.drawio', drawio);
+
+    const svg = (await call(p)).toString('utf-8');
+    const content = /content="([^"]*)"/.exec(svg)?.[1];
+    expect(content).toBeDefined();
+    // The attribute value must contain no bare `<`, `>` or `"` that would break
+    // out of the content="..." attribute or the SVG element.
+    expect(content).not.toMatch(/[<>"]/);
+    const decoded = content!
+      .replace(/&lt;/g, '<')
+      .replace(/&gt;/g, '>')
+      .replace(/&quot;/g, '"')
+      .replace(/&amp;/g, '&');
+    expect(decoded).toBe(drawio);
+  });
+});
@@ -8,6 +8,7 @@ import { createReadStream } from 'node:fs';
 import { promises as fs } from 'fs';
 import { Readable } from 'stream';
 import { getMimeType, sanitizeFileName } from '../../../common/helpers';
+import { htmlEscape } from '../../../common/helpers/html-escaper';
 import { v7 } from 'uuid';
 import { FileTask } from '@docmost/db/types/entity.types';
 import { getAttachmentFolderPath } from '../../../core/attachment/attachment.utils';
@@ -849,7 +850,12 @@ export class ImportAttachmentService {
  ): Promise<Buffer> {
    try {
      const drawioContent = await fs.readFile(drawioPath, 'utf-8');
-      const drawioBase64 = Buffer.from(drawioContent).toString('base64');
+      // Write the mxfile XML XML-entity-escaped (draw.io's native content= form),
+      // NOT base64. draw.io's editor decodes a base64 content= via Latin-1 atob
+      // (no UTF-8 step), turning every non-ASCII char (Cyrillic, ё, —) into
+      // mojibake; the entity-encoded form is decoded by the DOM as UTF-8 and
+      // opens intact. Docmost's own decoder reads both forms.
+      const drawioEscaped = this.xmlEscapeContent(drawioContent);

      let imageElement = '';
      // If we have a PNG, include it in the SVG
@@ -875,7 +881,7 @@ export class ImportAttachmentService {
      width="600"
      height="400"
      viewBox="0 0 600 400"
-      content="${drawioBase64}">${imageElement}</svg>`;
+      content="${drawioEscaped}">${imageElement}</svg>`;

      return Buffer.from(svgContent, 'utf-8');
    } catch (error) {
@@ -884,6 +890,24 @@ export class ImportAttachmentService {
    }
  }

+  /**
+   * Escape a string so it is safe as the value of a double-quoted XML attribute
+   * (the `content=` payload of a `.drawio.svg`). The shared `htmlEscape` covers
+   * `& < > " '` (a strict superset of what this attribute needs; the extra `'`
+   * escape is harmless in a `"`-delimited value). On top of that, the numeric
+   * char-refs for tab/newline/CR are required: a literal tab/newline/CR inside
+   * an attribute value is collapsed to a single space by XML attribute-value
+   * normalization on DOM read (both our decoder and the real draw.io editor),
+   * silently flattening multi-line labels and tab-bearing values. Char-refs
+   * survive that normalization (#507).
+   */
+  private xmlEscapeContent(s: string): string {
+    return htmlEscape(s)
+      .replace(/\t/g, '&#x9;')
+      .replace(/\n/g, '&#xa;')
+      .replace(/\r/g, '&#xd;');
+  }
+
  private async uploadWithRetry(opts: {
    abs: string;
    storageFilePath: string;
@@ -0,0 +1,67 @@
+// Importing ImportService transitively loads import-formatter.ts, which imports
+// the ESM-only @sindresorhus/slugify (not in jest's transform allowlist). It is
+// irrelevant to this path, so mock it to keep the module graph loadable (mirrors
+// the sibling import.service specs).
+jest.mock('@sindresorhus/slugify', () => ({
+  __esModule: true,
+  default: (input: string) => String(input),
+}));
+
+import { ImportService } from './import.service';
+
+// #502 BLOCKER 1: the server markdown import path (`/pages/import`) now accepts an
+// optional `disableMarkdownExtensions` flag threaded into `processMarkdown`.
+//   - MCP agent `createPage` sends it TRUE  -> extensions OFF (a `$…$` config span
+//     stays literal, a schemeless `www.host` is not autolinked).
+//   - a HUMAN file upload omits it (default FALSE) -> extensions ON, so a real
+//     `$x^2$` still becomes a formula (human imports unaffected).
+// `processMarkdown` only uses the imported converter (no injected deps on this
+// path), so the service is constructed with null deps for this focused unit test.
+
+function makeService(): ImportService {
+  return new ImportService(null as any, null as any, null as any, null as any);
+}
+
+function findAll(node: any, type: string, acc: any[] = []): any[] {
+  if (!node || typeof node !== 'object') return acc;
+  if (node.type === type) acc.push(node);
+  if (Array.isArray(node.content)) for (const c of node.content) findAll(c, type, acc);
+  return acc;
+}
+function hasLink(node: any): boolean {
+  return findAll(node, 'text').some((t: any) =>
+    t.marks?.some((m: any) => m.type === 'link'),
+  );
+}
+
+describe('ImportService.processMarkdown — #502 disableMarkdownExtensions', () => {
+  it('disableMarkdownExtensions=true (MCP createPage): `$…$` stays literal, no math', async () => {
+    const svc = makeService();
+    const doc = await svc.processMarkdown('export A=$FOO and B=$BAR done', true);
+    expect(findAll(doc, 'mathInline')).toHaveLength(0);
+  });
+
+  it('disableMarkdownExtensions=true: a schemeless www is NOT autolinked', async () => {
+    const svc = makeService();
+    const doc = await svc.processMarkdown('see www.example.com here', true);
+    expect(hasLink(doc)).toBe(false);
+  });
+
+  it('disableMarkdownExtensions=true: an explicit https:// STILL links', async () => {
+    const svc = makeService();
+    const doc = await svc.processMarkdown('see https://example.com here', true);
+    expect(hasLink(doc)).toBe(true);
+  });
+
+  it('DEFAULT (human upload): a real `$x^2$` DOES become a math node', async () => {
+    const svc = makeService();
+    const doc = await svc.processMarkdown('$x^2$');
+    expect(findAll(doc, 'mathInline')).toHaveLength(1);
+  });
+
+  it('DEFAULT (human upload): a schemeless www IS autolinked', async () => {
+    const svc = makeService();
+    const doc = await svc.processMarkdown('see www.example.com here');
+    expect(hasLink(doc)).toBe(true);
+  });
+});
@@ -52,6 +52,12 @@ export class ImportService {
    userId: string,
    spaceId: string,
    workspaceId: string,
+    // #502: when true, the markdown importer runs with the two layered
+    // extensions OFF (a `$…$` span stays literal text; a schemeless `www.host` is
+    // NOT autolinked). ONLY the MCP agent `createPage` path sets this; a HUMAN
+    // file upload never passes it, so it defaults false and math/autolink stay ON
+    // for human imports (their `$x^2$` still becomes a formula).
+    disableMarkdownExtensions = false,
  ) {
    const file = await filePromise;
    const fileBuffer = await file.toBuffer();
@@ -66,7 +72,10 @@ export class ImportService {

    try {
      if (fileExtension.endsWith('.md')) {
-        prosemirrorState = await this.processMarkdown(fileContent);
+        prosemirrorState = await this.processMarkdown(
+          fileContent,
+          disableMarkdownExtensions,
+        );
      } else if (fileExtension.endsWith('.html')) {
        prosemirrorState = await this.processHTML(fileContent);
      }
@@ -138,7 +147,12 @@ export class ImportService {
    return createdPage;
  }

-  async processMarkdown(markdownInput: string): Promise<any> {
+  async processMarkdown(
+    markdownInput: string,
+    // #502: forwarded to the importer. DEFAULT false keeps math + fuzzy autolink
+    // ON (human uploads unaffected); the MCP agent `createPage` path passes true.
+    disableMarkdownExtensions = false,
+  ): Promise<any> {
    // Canonical markdown -> ProseMirror JSON directly via
    // `@docmost/prosemirror-markdown` (issue #345) — no HTML intermediate and no
    // second editor-ext markdown layer. Foreign markdown surfaces the strict
@@ -147,7 +161,12 @@ export class ImportService {
    // The HTML-cleanup pass (`normalizeImportHtml`) is intentionally skipped here:
    // it targets foreign *HTML* (Notion/XWiki), which only ever arrives on the
    // `.html` path (`processHTML`), never as canonical markdown.
-    return markdownToProseMirror(normalizeForeignMarkdown(markdownInput));
+    return markdownToProseMirror(
+      normalizeForeignMarkdown(markdownInput),
+      disableMarkdownExtensions
+        ? { parseMath: false, fuzzyLinkify: false }
+        : undefined,
+    );
  }

  async processHTML(htmlInput: string): Promise<any> {
@@ -4,6 +4,7 @@ import { join } from 'path';
 import * as fs from 'node:fs';
 import fastifyStatic from '@fastify/static';
 import { EnvironmentService } from '../environment/environment.service';
+import { resolveClientDistPath } from '../../common/helpers/client-version';

 /**
 * Resolve the response headers for a statically served client asset.
@@ -56,14 +57,7 @@ export class StaticModule implements OnModuleInit {
    const httpAdapter = this.httpAdapterHost.httpAdapter;
    const app = httpAdapter.getInstance();

-    const clientDistPath = join(
-      __dirname,
-      '..',
-      '..',
-      '..',
-      '..',
-      'client/dist',
-    );
+    const clientDistPath = resolveClientDistPath();

    const indexFilePath = join(clientDistPath, 'index.html');

@@ -9,10 +9,14 @@ import {
 import { Server, Socket } from 'socket.io';
 import { TokenService } from '../core/auth/services/token.service';
 import { JwtPayload, JwtType } from '../core/auth/dto/jwt-payload';
-import { OnModuleDestroy } from '@nestjs/common';
+import { Logger, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
 import { SpaceMemberRepo } from '@docmost/db/repos/space/space-member.repo';
 import { WsService } from './ws.service';
 import { getSpaceRoomName, getUserRoomName } from './ws.utils';
+import {
+  readClientBuildVersion,
+  resolveClientDistPath,
+} from '../common/helpers/client-version';
 import * as cookie from 'cookie';

@WebSocketGateway({
@@ -20,17 +24,40 @@ import * as cookie from 'cookie';
  transports: ['websocket'],
 })
 export class WsGateway
-  implements OnGatewayConnection, OnGatewayInit, OnModuleDestroy
+  implements
+    OnGatewayConnection,
+    OnGatewayInit,
+    OnModuleInit,
+    OnModuleDestroy
 {
  @WebSocketServer()
  server: Server;

+  private readonly logger = new Logger(WsGateway.name);
+
+  // The build version of the client bundle shipped in this image, read once at
+  // startup from client/dist/version.json (single source of truth, same value
+  // baked into the client's APP_VERSION). Empty string => version.json missing
+  // or empty => the proactive version-coherence reload feature stays inert.
+  private appVersion = '';
+
  constructor(
    private tokenService: TokenService,
    private spaceMemberRepo: SpaceMemberRepo,
    private wsService: WsService,
  ) {}

+  onModuleInit(): void {
+    this.appVersion = readClientBuildVersion(resolveClientDistPath());
+    if (this.appVersion) {
+      this.logger.log(`app-version reload: ACTIVE (v=${this.appVersion})`);
+    } else {
+      this.logger.log(
+        'app-version reload: DISABLED (version.json missing/empty)',
+      );
+    }
+  }
+
  afterInit(server: Server): void {
    this.wsService.setServer(server);
  }
@@ -55,6 +82,14 @@ export class WsGateway
      const spaceRooms = userSpaceIds.map((id) => getSpaceRoomName(id));

      client.join([userRoom, workspaceRoom, ...spaceRooms]);
+
+      // Announce this container's client build version to the freshly
+      // authenticated socket. On a redeploy the client reconnects to the new
+      // container and receives the new version here, letting it guard-reload
+      // before it hits a stale lazy chunk. Per-connect only (no broadcast):
+      // natural reconnect covers both single-container and cluster without a
+      // thundering-herd fleet reload.
+      client.emit('app-version', { version: this.appVersion });
    } catch (err) {
      client.emit('Unauthorized');
      client.disconnect();
@@ -0,0 +1,412 @@
+import * as http from 'node:http';
+import { Kysely } from 'kysely';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { MockLanguageModelV3, convertArrayToReadableStream } from 'ai/test';
+import { AiChatRepo } from '@docmost/db/repos/ai-chat/ai-chat.repo';
+import { AiChatMessageRepo } from '@docmost/db/repos/ai-chat/ai-chat-message.repo';
+import { AiChatRunStepRepo } from '@docmost/db/repos/ai-chat/ai-chat-run-step.repo';
+import {
+  AiChatService,
+  assembleStepParts,
+  assistantParts,
+  rowHasInlineParts,
+  stepMarkerMetadata,
+} from 'src/core/ai-chat/ai-chat.service';
+import {
+  getTestDb,
+  destroyTestDb,
+  createWorkspace,
+  createUser,
+  createChat,
+  createMessage,
+} from './db';
+
+/**
+ * #492 append-persist — the REAL onStep WRITE path (F2) and the model-REPLAY
+ * hydration path (F1), driven through `AiChatService.stream` against a LIVE
+ * Postgres with a REAL `AiChatRunStepRepo` INJECTED. The existing append-persist
+ * int-specs hand-roll the insert+marker cycle via the repos directly and build
+ * the service with `aiChatRunStepRepo: undefined` (only the legacy-fallback branch
+ * is covered), so an off-by-one on `stepsPersisted-1`, a wrong `capturedSteps`
+ * slice, or a broken marker payload would pass all of them. These tests exercise
+ * the actual `updateStreaming` append-persist branch end to end.
+ *
+ * The seam is the injected `model` (a seeded `MockLanguageModelV3` from `ai/test`)
+ * plus a REAL Node `ServerResponse` as the hijacked socket — mirrors
+ * ai-chat-stream.int-spec.ts.
+ */
+
+const sleep = (ms: number) => new Promise((r) => setTimeout(r, ms));
+
+async function waitFor(
+  cond: () => Promise<boolean> | boolean,
+  { timeoutMs = 15_000, stepMs = 25 } = {},
+): Promise<void> {
+  const start = Date.now();
+  while (Date.now() - start < timeoutMs) {
+    if (await cond()) return;
+    await sleep(stepMs);
+  }
+  throw new Error('waitFor: condition not met within timeout');
+}
+
+// A real Node ServerResponse wired to a live socket (identical helper to the
+// stream int-spec) so the SDK's pipe/heartbeat writes behave as in prod.
+function makeRealResponse(): Promise<{
+  res: http.ServerResponse;
+  cleanup: () => Promise<void>;
+}> {
+  return new Promise((resolve) => {
+    const server = http.createServer((_req, res) => {
+      resolve({
+        res,
+        cleanup: () =>
+          new Promise<void>((done) => {
+            try {
+              if (!res.writableEnded) res.end();
+            } catch {
+              /* socket already gone */
+            }
+            server.close(() => done());
+          }),
+      });
+    });
+    server.listen(0, () => {
+      const port = (server.address() as any).port;
+      const creq = http.request({ port, method: 'GET' }, (cres) => {
+        cres.resume();
+      });
+      creq.on('error', () => undefined);
+      creq.end();
+    });
+  });
+}
+
+// Stream parts for a normal, successful single-step turn.
+function successStream() {
+  return convertArrayToReadableStream([
+    { type: 'stream-start', warnings: [] },
+    { type: 'text-start', id: 't1' },
+    { type: 'text-delta', id: 't1', delta: 'Hello' },
+    { type: 'text-delta', id: 't1', delta: ' there' },
+    { type: 'text-end', id: 't1' },
+    {
+      type: 'finish',
+      finishReason: 'stop',
+      usage: { inputTokens: 10, outputTokens: 5, totalTokens: 15 },
+    },
+  ] as any);
+}
+
+// A THREE-step turn: steps 0 and 1 each emit text + an `echo` tool call (the SDK
+// runs the tool and continues); step 2 answers and stops. Three steps is
+// deliberate: the LAST finished step's append-persist write races the terminal
+// finalize (which writes the full inline parts anyway, so a lost last-step row is
+// by design), but the NON-final steps 0 and 1 always drain to the steps table
+// before finalize — so those are what the test asserts on deterministically.
+function threeStepModel(): MockLanguageModelV3 {
+  let step = 0;
+  const toolStep = (i: number) => ({
+    stream: convertArrayToReadableStream([
+      { type: 'stream-start', warnings: [] },
+      { type: 'text-start', id: `s${i}` },
+      { type: 'text-delta', id: `s${i}`, delta: `step ${i} ` },
+      { type: 'text-end', id: `s${i}` },
+      {
+        type: 'tool-call',
+        toolCallId: `c${i}`,
+        toolName: 'echo',
+        input: JSON.stringify({ msg: `m${i}` }),
+      },
+      {
+        type: 'finish',
+        finishReason: 'tool-calls',
+        usage: { inputTokens: 5, outputTokens: 3, totalTokens: 8 },
+      },
+    ] as any),
+  });
+  return new MockLanguageModelV3({
+    doStream: async () => {
+      const n = step++;
+      // Realistic inter-step latency. A real model spends seconds per step, so the
+      // fire-and-forget per-step write chain drains to the steps table BETWEEN
+      // steps; the mock otherwise collapses all steps into microseconds and the
+      // terminal finalize wins the race before any but the first step persists.
+      if (n > 0) await sleep(200);
+      if (n < 2) return toolStep(n);
+      return {
+        stream: convertArrayToReadableStream([
+          { type: 'stream-start', warnings: [] },
+          { type: 'text-start', id: 's2' },
+          { type: 'text-delta', id: 's2', delta: 'final answer' },
+          { type: 'text-end', id: 's2' },
+          {
+            type: 'finish',
+            finishReason: 'stop',
+            usage: { inputTokens: 6, outputTokens: 4, totalTokens: 10 },
+          },
+        ] as any),
+      };
+    },
+  } as any);
+}
+
+describe('#492 append-persist service paths [integration]', () => {
+  let db: Kysely<any>;
+  let aiChatRepo: AiChatRepo;
+  let msgRepo: AiChatMessageRepo;
+  let stepRepo: AiChatRunStepRepo;
+  let workspaceId: string;
+  let userId: string;
+
+  let closeCalls: number;
+  const mcpClients = {
+    toolsFor: async () => ({
+      tools: {},
+      clients: [
+        {
+          close: async () => {
+            closeCalls += 1;
+          },
+        },
+      ],
+      outcomes: [],
+      instructions: [],
+    }),
+  };
+
+  // Build the service WITH a REAL AiChatRunStepRepo injected (the property under
+  // test) — unlike the legacy-fallback harness that passes it as undefined.
+  const echoTool = tool({
+    description: 'echo the message back',
+    inputSchema: z.object({ msg: z.string() }),
+    execute: async ({ msg }) => ({ echoed: msg }),
+  });
+
+  function buildService(): AiChatService {
+    return new AiChatService(
+      { getChatModel: async () => null } as any,
+      aiChatRepo,
+      msgRepo,
+      {} as any, // aiChatPageSnapshotRepo
+      { resolve: async () => null } as any, // aiSettings
+      { forUser: async () => ({ echo: echoTool }) } as any, // tools
+      mcpClients as any,
+      {} as any, // aiAgentRoleRepo
+      {} as any, // pageRepo
+      {} as any, // pageAccess
+      {
+        isAiChatDeferredToolsEnabled: () => false,
+        isAiChatFinalStepLockdownEnabled: () => false,
+      } as any, // environment (deferred OFF -> all tools active every step)
+      undefined, // streamRegistry
+      undefined, // aiChatRunService
+      stepRepo, // #492 aiChatRunStepRepo — the append-persist backend
+    );
+  }
+
+  function userUiMessage(text: string) {
+    return {
+      id: `u-${Math.random()}`,
+      role: 'user',
+      parts: [{ type: 'text', text }],
+    };
+  }
+
+  async function runStream(opts: {
+    model: MockLanguageModelV3;
+    chatId: string;
+    body: any;
+  }): Promise<void> {
+    closeCalls = 0;
+    const service = buildService();
+    const { res, cleanup } = await makeRealResponse();
+    try {
+      await service.stream({
+        user: { id: userId, workspaceId } as any,
+        workspace: { id: workspaceId, name: 'WS' } as any,
+        sessionId: 'sess-1',
+        body: opts.body,
+        res: { raw: res } as any,
+        signal: new AbortController().signal,
+        model: opts.model as any,
+        role: null,
+      } as any);
+      await waitFor(async () => {
+        const rows = await msgRepo.findAllByChat(opts.chatId, workspaceId);
+        return rows.some(
+          (r) =>
+            r.role === 'assistant' &&
+            ['completed', 'error', 'aborted'].includes(r.status as string),
+        );
+      });
+      await waitFor(() => closeCalls > 0, { timeoutMs: 5_000 });
+    } finally {
+      await cleanup();
+    }
+  }
+
+  beforeAll(async () => {
+    db = getTestDb();
+    aiChatRepo = new AiChatRepo(db as any);
+    msgRepo = new AiChatMessageRepo(db as any);
+    stepRepo = new AiChatRunStepRepo(db as any);
+    workspaceId = (await createWorkspace(db)).id;
+    userId = (await createUser(db, workspaceId)).id;
+  });
+
+  afterAll(async () => {
+    await destroyTestDb();
+  });
+
+  // --- F2: the real onStep append-persist WRITE branch -----------------------
+  it('drives steps through the real onStep path: per-step rows + marker match a single-row flush', async () => {
+    const chatId = (await createChat(db, { workspaceId, creatorId: userId })).id;
+    const model = threeStepModel();
+
+    // Capture the mid-run step-marker UPDATEs the append-persist branch writes on
+    // the assistant row (a { parts: [], toolTraceVersion, stepsPersisted } patch).
+    const updateSpy = jest.spyOn(msgRepo, 'update');
+    try {
+      await runStream({
+        model,
+        chatId,
+        body: { chatId, messages: [userUiMessage('call the tool then answer')] },
+      });
+
+      const rows = await msgRepo.findAllByChat(chatId, workspaceId);
+      const assistant = rows.find((r) => r.role === 'assistant')!;
+      expect(assistant).toBeDefined();
+      expect(assistant.status).toBe('completed');
+      // The turn finalizes with the FULL inline parts assembled by a single-row
+      // flush (assistantParts over every step) — the baseline the per-step slices
+      // must reproduce.
+      expect(rowHasInlineParts(assistant)).toBe(true);
+      const finalParts = (assistant.metadata as { parts: any[] }).parts;
+
+      // The two NON-final finished steps each landed their own row, in stepIndex
+      // order. (The fire-and-forget write chain drains before the next step, so
+      // poll until both are on disk; the LAST step's write may lose the finalize
+      // race, which is by design — its parts are already in `finalParts`.)
+      await waitFor(async () => {
+        const s = await stepRepo.findByMessage(assistant.id, workspaceId);
+        return s.length >= 2;
+      });
+      const steps = await stepRepo.findByMessage(assistant.id, workspaceId);
+      expect(steps[0].stepIndex).toBe(0);
+      expect(steps[1].stepIndex).toBe(1);
+
+      // Each per-step row carries a NON-trivial slice: this step's text part + its
+      // paired tool part (guards a mutation that persists empty/whole-turn parts).
+      const s0 = steps[0].parts as any[];
+      expect(s0).toContainEqual({ type: 'text', text: 'step 0 ' });
+      expect(s0.some((p) => p.type === 'tool-echo')).toBe(true);
+
+      // The per-step slices are EXACTLY the corresponding prefix of the single-row
+      // flush: assembleStepParts([step0, step1]) === finalParts[0 .. len0+len1].
+      // This is what an off-by-one on `stepsPersisted-1` (a wrong `capturedSteps`
+      // slice) or a shifted stepIndex breaks — the prefix no longer aligns.
+      const prefixLen =
+        (steps[0].parts as any[]).length + (steps[1].parts as any[]).length;
+      expect(assembleStepParts([steps[0], steps[1]] as any)).toEqual(
+        finalParts.slice(0, prefixLen),
+      );
+
+      // The mid-run step markers advanced 1 -> 2 -> ... (the resume frontier), each
+      // a shape-stable empty-parts marker equal to a single-row flush's marker.
+      const markerCounts = updateSpy.mock.calls
+        .map((c) => (c[2] as any)?.metadata)
+        .filter(
+          (m) =>
+            m &&
+            Array.isArray(m.parts) &&
+            m.parts.length === 0 &&
+            typeof m.stepsPersisted === 'number',
+        )
+        .map((m) => m.stepsPersisted);
+      // Monotonic from 1, covering at least the two non-final steps.
+      expect(markerCounts.slice(0, 2)).toEqual([1, 2]);
+      expect(
+        updateSpy.mock.calls
+          .map((c) => (c[2] as any)?.metadata)
+          .find((m) => m && m.stepsPersisted === 2),
+      ).toEqual(stepMarkerMetadata(2));
+    } finally {
+      updateSpy.mockRestore();
+    }
+  }, 60_000);
+
+  // --- F1: model-REPLAY hydrates a hard-crashed mid-run turn from the steps table
+  it('replays a hard-crashed mid-run turn WITH its partial steps hydrated from the steps table', async () => {
+    const chatId = (await createChat(db, { workspaceId, creatorId: userId })).id;
+
+    // Prior turn: a genuine user question...
+    await createMessage(db, {
+      workspaceId,
+      chatId,
+      userId,
+      role: 'user',
+      content: 'What is in the design doc?',
+      createdAt: new Date(Date.now() - 3000),
+    });
+    // ...and an assistant row that a HARD crash (SIGKILL/OOM) left mid-run: only a
+    // step marker on the row (metadata.parts:[] , content:''), NO terminal
+    // callback ever fired, so its real parts live ONLY in ai_chat_run_steps.
+    const crashed = await createMessage(db, {
+      workspaceId,
+      chatId,
+      role: 'assistant',
+      content: '',
+      status: 'aborted',
+      metadata: stepMarkerMetadata(1),
+      createdAt: new Date(Date.now() - 2000),
+    });
+    // The durable partial step: some reasoning text + a completed getPage tool
+    // call (input + output), exactly what #183 step-granular durability preserves.
+    await stepRepo.insertStep(
+      crashed.id,
+      workspaceId,
+      0,
+      assistantParts(
+        [
+          {
+            text: 'HYDRATED_PARTIAL_STEP the doc says',
+            toolCalls: [
+              { toolCallId: 'g1', toolName: 'getPage', input: { id: 'p1' } },
+            ],
+            toolResults: [
+              {
+                toolCallId: 'g1',
+                toolName: 'getPage',
+                output: { id: 'p1', body: 'PARTIAL_TOOL_OUTPUT budget section' },
+              },
+            ],
+          } as any,
+        ],
+        '',
+      ),
+    );
+
+    // The NEXT turn: the model just answers. The service must REPLAY the crashed
+    // assistant turn with its partial parts hydrated from the steps table.
+    const model = new MockLanguageModelV3({
+      doStream: async () => ({ stream: successStream() }),
+    } as any);
+    await runStream({
+      model,
+      chatId,
+      body: { chatId, messages: [userUiMessage('Continue please')] },
+    });
+
+    expect(model.doStreamCalls.length).toBeGreaterThan(0);
+    const prompt = JSON.stringify(model.doStreamCalls[0].prompt);
+    // The partial step's TEXT reached the model context (it would be an empty text
+    // part without hydration — rowToUiMessage falls back to `content:''`).
+    expect(prompt).toContain('HYDRATED_PARTIAL_STEP');
+    // The partial TOOL RESULT survived too (durable in the steps table, replayed).
+    expect(prompt).toContain('PARTIAL_TOOL_OUTPUT');
+    // The genuine prior user turn is present as well (sanity: real history replay).
+    expect(prompt).toContain('What is in the design doc?');
+  }, 60_000);
+});
@@ -0,0 +1,173 @@
+import { randomBytes } from 'crypto';
+import { Kysely, sql } from 'kysely';
+import { AiChatRunStepRepo } from '@docmost/db/repos/ai-chat/ai-chat-run-step.repo';
+import { AiChatMessageRepo } from '@docmost/db/repos/ai-chat/ai-chat-message.repo';
+import {
+  assistantParts,
+  flushAssistant,
+  stepMarkerMetadata,
+} from '../../src/core/ai-chat/ai-chat.service';
+import {
+  getTestDb,
+  destroyTestDb,
+  createWorkspace,
+  createUser,
+  createChat,
+} from './db';
+
+/**
+ * #492 append-persist — WRITE-VOLUME regression on a LIVE Postgres, measured via
+ * the `pg_current_wal_lsn()` delta around a realistic multi-step run driven through
+ * the REAL repos (not a mock — a mock cannot observe MVCC/TOAST rewrite volume, the
+ * whole point). Proves the core claim:
+ *
+ *   NEW (per-step INSERT into ai_chat_run_steps + a CHEAP step-marker UPDATE on the
+ *   message row) writes O(Σ steps) of WAL — each step writes only its own bytes.
+ *
+ *   OLD (the pre-#492 full-row rewrite: re-persist the GROWING metadata.parts on
+ *   every onStepFinish) writes O(n²) — step k rewrites the whole TOASTed jsonb of
+ *   all k prior outputs.
+ *
+ * The OLD path here IS the reverted behavior, so this doubles as the mutation
+ * check: swapping the new path back to `flushAssistant` full-row UPDATEs reddens
+ * the assertion (OLD is many times larger).
+ */
+type Step = {
+  text: string;
+  toolCalls: Array<{ toolCallId: string; toolName: string; input: unknown }>;
+  toolResults: Array<{ toolCallId: string; toolName: string; output: unknown }>;
+};
+
+// ~100 KB INCOMPRESSIBLE output per step (a page read). Random base64 so TOAST
+// cannot compress it away and hide the real write volume.
+function makeStep(i: number, outputBytes = 100_000): Step {
+  const body = randomBytes(Math.ceil(outputBytes * 0.75)).toString('base64');
+  return {
+    text: `step ${i} reasoning`,
+    toolCalls: [
+      { toolCallId: `c${i}`, toolName: 'getPage', input: { id: `p${i}` } },
+    ],
+    toolResults: [
+      {
+        toolCallId: `c${i}`,
+        toolName: 'getPage',
+        output: { id: `p${i}`, title: `Page ${i}`, body },
+      },
+    ],
+  };
+}
+
+async function walDelta(
+  db: Kysely<any>,
+  fn: () => Promise<void>,
+): Promise<number> {
+  const before = (
+    await sql<{ l: string }>`select pg_current_wal_lsn() as l`.execute(db)
+  ).rows[0].l;
+  await fn();
+  // NOTE: no pg_switch_wal() — a segment switch pads the LSN to the next 16 MB
+  // boundary and would swamp the delta. The raw LSN advances by the WAL bytes.
+  const after = (
+    await sql<{ l: string }>`select pg_current_wal_lsn() as l`.execute(db)
+  ).rows[0].l;
+  return Number(
+    (
+      await sql<{
+        d: string;
+      }>`select pg_wal_lsn_diff(${after}::pg_lsn, ${before}::pg_lsn) as d`.execute(
+        db,
+      )
+    ).rows[0].d,
+  );
+}
+
+describe('#492 append-persist write volume (pg_current_wal_lsn delta) [integration]', () => {
+  let db: Kysely<any>;
+  let stepRepo: AiChatRunStepRepo;
+  let msgRepo: AiChatMessageRepo;
+  let workspaceId: string;
+  let userId: string;
+  let chatId: string;
+
+  beforeAll(async () => {
+    db = getTestDb();
+    stepRepo = new AiChatRunStepRepo(db as any);
+    msgRepo = new AiChatMessageRepo(db as any);
+    workspaceId = (await createWorkspace(db)).id;
+    userId = (await createUser(db, workspaceId)).id;
+    chatId = (await createChat(db, { workspaceId, creatorId: userId })).id;
+  });
+
+  afterAll(async () => {
+    await destroyTestDb();
+  });
+
+  const seedRow = () =>
+    msgRepo.insert({
+      chatId,
+      workspaceId,
+      userId,
+      role: 'assistant',
+      content: '',
+      status: 'streaming',
+      metadata: stepMarkerMetadata(0) as never,
+    });
+
+  const STEPS = 40;
+
+  it('NEW per-step INSERT is O(Σ steps); OLD full-row rewrite is O(n²)', async () => {
+    const steps: Step[] = [];
+    for (let i = 0; i < STEPS; i++) steps.push(makeStep(i));
+
+    // NEW: per-step INSERT of THIS step's parts + a cheap marker UPDATE.
+    const newRow = await seedRow();
+    const newWal = await walDelta(db, async () => {
+      for (let i = 0; i < STEPS; i++) {
+        await stepRepo.insertStep(
+          newRow.id,
+          workspaceId,
+          i,
+          assistantParts([steps[i]], ''),
+        );
+        await msgRepo.update(
+          newRow.id,
+          workspaceId,
+          { metadata: stepMarkerMetadata(i + 1) },
+          { onlyIfStreaming: true },
+        );
+      }
+    });
+
+    // OLD (the pre-#492 revert): re-persist the GROWING metadata.parts on the
+    // message row on every step.
+    const oldRow = await seedRow();
+    const oldWal = await walDelta(db, async () => {
+      const acc: Step[] = [];
+      for (let i = 0; i < STEPS; i++) {
+        acc.push(steps[i]);
+        await msgRepo.update(
+          oldRow.id,
+          workspaceId,
+          flushAssistant(acc as never, '', 'streaming'),
+          { onlyIfStreaming: true },
+        );
+      }
+    });
+
+    // eslint-disable-next-line no-console
+    console.log(
+      `[#492 WAL] ${STEPS} steps ×100KB: new=${(newWal / 1e6).toFixed(1)}MB ` +
+        `old=${(oldWal / 1e6).toFixed(1)}MB (${(oldWal / newWal).toFixed(
+          1,
+        )}x smaller)`,
+    );
+
+    // O(Σ steps): ~STEPS × (100KB output + marker) of WAL. 40 × ~100KB parts plus
+    // 40 tiny markers is a few tens of MB at most — bounded, linear in step count.
+    expect(newWal).toBeLessThan(30_000_000);
+    // O(n²): step k rewrites ~k × 100KB. Σ over 40 steps ≈ 80+ MB — far larger.
+    expect(oldWal).toBeGreaterThan(30_000_000);
+    // The load-bearing claim: the new path writes a small FRACTION of the old.
+    expect(newWal).toBeLessThan(oldWal * 0.35);
+  }, 120_000);
+});
--- a/Show More
+++ b/Show More