test(collab): cover the title-change ⋈ empty-guard intersection (F1)

The develop rebase merged the #120 title-only-change branch and the
#248/#251 store-side empty-guard into one onStoreDocument. The existing 14
tests exercise each only in isolation (empty-guard tests send no title
fragment; title tests send a non-empty body), so none reached the
empty-guard's blocking branch with titleChanged===true. Add two paired
regression tests on that exact junction:

- empty body + a changed non-empty title over non-empty persisted content,
  no intentional-clear → the empty-guard blocks the WHOLE store, dropping
  the simultaneous rename too (updatePage not called); the rich content and
  old title survive.
- the same doc with a deliberate clear armed via the real stateless
  transport → the empty body is allowed and the rename rides along on the
  same body-path updatePage (title + empty content persisted).

The pair makes Test 1 non-vacuous: same doc, only the clear differs, and
Test 2 proves updatePage IS reachable — so Test 1's "not called" is the
guard blocking, not an unreached path. Test-only; no production change.

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

.env.example

@@ -92,6 +92,19 @@ IFRAME_EMBED_ALLOWED=false
 # Example: https://intranet.example.com,https://portal.example.com
 IFRAME_ALLOWED_ORIGINS=
 
+# Comma-separated list of additional origins allowed to call the API via CORS.
+# The APP_URL origin and native mobile (Capacitor) origins are always allowed.
+# Leave empty for a same-origin (web-only) deployment.
+CORS_ALLOWED_ORIGINS=
+
+# Expose OpenAPI/Swagger docs at /api/docs (development/debugging aid only).
+SWAGGER_ENABLED=false
+
+# Capacitor (mobile shell): hosted client URL loaded by the iOS shell so the
+# AGPL web client is NOT bundled into the .ipa (see docs/mobile-app-plan.md §9).
+# Leave empty for Android bundled mode / local development.
+CAP_SERVER_URL=
+
 # Enable debug logging in production (default: false)
 DEBUG_MODE=false
 

.gitignore

@@ -49,3 +49,8 @@ lerna-debug.log*
 
 # Self-hosted VAD / onnxruntime-web assets (copied from node_modules at dev/build time)
 apps/client/public/vad/
+
+# Capacitor native platform projects (generated locally via 'npx cap add ios|android')
+/ios
+/android
+.capacitor

CHANGELOG.md

@@ -12,6 +12,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- **Editable captions for images.** Images gain an optional caption shown
+  below them, edited inline from the image bubble menu and stored as a `caption` attribute. Captions round-trip
+  losslessly through markdown as a `data-caption` attribute on the image, so
+  they survive export/import unchanged. (#221)
+
 - **Quick-create regular and temporary notes from the Home and Space screens.**
   The Home screen now shows a second action next to "New note" that creates a
   *temporary* note (one that auto-moves to Trash after the workspace lifetime),
@@ -67,6 +72,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   `nosniff` + restrictive CSP + attachment disposition for non-image mimes) and
   are RAM-only, bound to the instance that created them. Tunable via five
   `SANDBOX_*` env vars (see `.env.example`). (#243)
+- **Offline reading support**: opened pages, their sidebar tree, breadcrumb
+  children, and comments are cached in IndexedDB (TanStack Query persister plus
+  `y-indexeddb` for the page's Yjs document), and a PWA service worker
+  (vite-plugin-pwa) serves an app shell so previously opened pages stay readable
+  offline. The two offline stores (the persisted query cache and the Yjs page
+  documents) are cleared on logout AND on sign-in so a previous user's private
+  data does not remain in the browser; the same purge also defensively drops any
+  legacy service-worker `api-get-cache` left by older clients (current builds
+  serve `/api` as NetworkOnly, so there is no active service-worker API cache).
+- **Mobile bootstrap**: a `returnToken` opt-in on login so native/mobile clients
+  can request the access JWT in the response body (`data.authToken`) in addition
+  to the httpOnly cookie (the web client stays cookie-only); an optional
+  OpenAPI/Swagger UI at `/api/docs` gated by `SWAGGER_ENABLED` (off by default);
+  and new env vars `CORS_ALLOWED_ORIGINS`, `SWAGGER_ENABLED`, `CAP_SERVER_URL`.
 - **Inline spoiler mark — hide text behind click-to-reveal blur.** Selected text
   can be marked as a spoiler from a new bubble-menu toggle, or typed Discord-style
   with the `||text||` input rule; the rendered span blurs until clicked to reveal.
@@ -92,6 +111,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   JSON-compatible schema (no custom tags / no code execution) behind the same
   size-cap, redirect and path-traversal guards. The `AI_AGENT_ROLES_CATALOG_URL`
   base-URL contract is unchanged. (#229)
+- **CORS is now an explicit allowlist** (replaces the previous unconfigured
+  `app.enableCors()`). The same-origin web client is unaffected, but any
+  separately-hosted cross-domain client must now be listed in
+  `CORS_ALLOWED_ORIGINS` (native Capacitor/Ionic/localhost WebView origins are
+  allowed automatically). Requests with no `Origin` header (server-to-server)
+  are still allowed. **Upgrade note:** the old bare `app.enableCors()` reflected
+  *any* origin (with `credentials:false`), so any previously-working cross-domain
+  REST/browser client is now rejected until its origin is added to
+  `CORS_ALLOWED_ORIGINS` (see `.env.example`).
 
 ### Fixed
 
@@ -129,6 +157,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   "This address is in use. Saving will move it to this page." — and keeps Save
   enabled, so the existing reassign-confirm flow (`409 ALIAS_REASSIGN_REQUIRED` →
   "Move custom address?") is discoverable instead of reading as terminal. (#227)
+- **A non-empty page can no longer be silently lost to a momentarily-empty live
+  document.** The server's persistence guard now refuses to overwrite non-empty
+  persisted content with an empty live Y.Doc — a transient emptiness from a
+  glitch, a bad merge, or an emptying transclusion no longer wipes the saved
+  page. A *deliberate* clear still works: a select-all + Delete in the editor
+  emits a single-use "intentional clear" signal that lets exactly that one empty
+  write through the guard, so genuinely emptying a page is persisted while
+  accidental empties are blocked. (#248, #251)
 
 ### Security
 

apps/client/index.html

@@ -10,6 +10,7 @@
     <meta name="theme-color" content="#0E1117" media="(prefers-color-scheme: dark)" />
     <meta name="theme-color" content="#f6f7f9" media="(prefers-color-scheme: light)" />
     <link rel="manifest" href="/manifest.json" />
+    <link rel="apple-touch-icon" href="/icons/app-icon-192x192.png" />
     <meta name="mobile-web-app-capable" content="yes" />
     <meta name="apple-touch-fullscreen" content="yes" />
     <meta name="apple-mobile-web-app-title" content="Gitmost" />

apps/client/package.json

@@ -33,7 +33,9 @@
     "@slidoapp/emoji-mart-data": "1.2.4",
     "@slidoapp/emoji-mart-react": "1.1.5",
     "@tabler/icons-react": "3.40.0",
+    "@tanstack/query-async-storage-persister": "5.90.17",
     "@tanstack/react-query": "5.90.17",
+    "@tanstack/react-query-persist-client": "5.90.17",
     "@tanstack/react-virtual": "3.13.24",
     "ai": "6.0.207",
     "alfaaz": "1.1.0",
@@ -45,6 +47,7 @@
     "highlightjs-sap-abap": "0.3.0",
     "i18next": "25.10.1",
     "i18next-http-backend": "3.0.6",
+    "idb-keyval": "6.2.5",
     "jotai": "2.18.1",
     "jotai-optics": "0.4.0",
     "js-cookie": "3.0.7",
@@ -95,6 +98,7 @@
     "typescript": "5.9.3",
     "typescript-eslint": "8.57.1",
     "vite": "8.0.5",
+    "vite-plugin-pwa": "1.3.0",
     "vitest": "4.1.6"
   }
 }

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

@@ -286,6 +286,9 @@
   "Alt text": "Alt text",
   "Describe this for accessibility.": "Describe this for accessibility.",
   "Add a description": "Add a description",
+  "Caption": "Caption",
+  "Add a caption": "Add a caption",
+  "Shown below the image.": "Shown below the image.",
   "Justify": "Justify",
   "Merge cells": "Merge cells",
   "Split cell": "Split cell",
@@ -465,6 +468,18 @@
   "Move page": "Move page",
   "Move page to a different space.": "Move page to a different space.",
   "Real-time editor connection lost. Retrying...": "Real-time editor connection lost. Retrying...",
+  "Offline — changes are saved locally and will sync when you reconnect": "Offline — changes are saved locally and will sync when you reconnect",
+  "Syncing changes…": "Syncing changes…",
+  "All changes synced": "All changes synced",
+  "Update available": "Update available",
+  "Reload": "Reload",
+  "Make available offline": "Make available offline",
+  "Saving page for offline use...": "Saving page for offline use...",
+  "Page is now available offline": "Page is now available offline",
+  "Failed to make page available offline": "Failed to make page available offline",
+  "You're offline": "You're offline",
+  "This page hasn't been saved for offline use, so it can't be loaded right now. Reconnect to the internet and try again.": "This page hasn't been saved for offline use, so it can't be loaded right now. Reconnect to the internet and try again.",
+  "Retry": "Retry",
   "Table of contents": "Table of contents",
   "Add headings (H1, H2, H3) to generate a table of contents.": "Add headings (H1, H2, H3) to generate a table of contents.",
   "Share": "Share",

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

@@ -475,6 +475,18 @@
   "Move page": "Переместить страницу",
   "Move page to a different space.": "Переместите страницу в другое пространство.",
   "Real-time editor connection lost. Retrying...": "Соединение с редактором в реальном времени потеряно. Повторная попытка...",
+  "Offline — changes are saved locally and will sync when you reconnect": "Нет сети — изменения сохраняются локально и синхронизируются при восстановлении соединения",
+  "Syncing changes…": "Синхронизация изменений…",
+  "All changes synced": "Все изменения синхронизированы",
+  "Update available": "Доступно обновление",
+  "Reload": "Перезагрузить",
+  "Make available offline": "Сделать доступным офлайн",
+  "Saving page for offline use...": "Сохраняем страницу для офлайн-доступа…",
+  "Page is now available offline": "Страница доступна офлайн",
+  "Failed to make page available offline": "Не удалось сделать страницу доступной офлайн",
+  "You're offline": "Вы офлайн",
+  "This page hasn't been saved for offline use, so it can't be loaded right now. Reconnect to the internet and try again.": "Эта страница не была сохранена для офлайн-доступа, поэтому её нельзя загрузить сейчас. Подключитесь к интернету и попробуйте снова.",
+  "Retry": "Повторить",
   "Table of contents": "Оглавление",
   "Add headings (H1, H2, H3) to generate a table of contents.": "Добавьте заголовки (H1, H2, H3), чтобы создать оглавление.",
   "Share": "Поделиться",

apps/client/public/manifest.json

@@ -1,30 +1,19 @@
 {
+  "id": "/",
   "name": "Gitmost",
   "short_name": "Gitmost",
+  "description": "Gitmost - open-source collaborative documentation and knowledge base.",
+  "lang": "en",
   "start_url": "/",
+  "scope": "/",
   "display": "standalone",
+  "orientation": "any",
   "background_color": "#0E1117",
   "theme_color": "#0E1117",
   "icons": [
-    {
-      "src": "icons/favicon-16x16.png",
-      "type": "image/png",
-      "sizes": "16x16"
-    },
-    {
-      "src": "icons/favicon-32x32.png",
-      "type": "image/png",
-      "sizes": "32x32"
-    },
-    {
-      "src": "icons/app-icon-192x192.png",
-      "type": "image/png",
-      "sizes": "180x180 192x192"
-    },
-    {
-      "src": "icons/app-icon-512x512.png",
-      "type": "image/png",
-      "sizes": "512x512"
-    }
+    { "src": "icons/favicon-16x16.png", "type": "image/png", "sizes": "16x16" },
+    { "src": "icons/favicon-32x32.png", "type": "image/png", "sizes": "32x32" },
+    { "src": "icons/app-icon-192x192.png", "type": "image/png", "sizes": "192x192", "purpose": "any" },
+    { "src": "icons/app-icon-512x512.png", "type": "image/png", "sizes": "512x512", "purpose": "any" }
   ]
 }

apps/client/src/features/auth/hooks/use-auth.test.ts

@@ -0,0 +1,154 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { renderHook, act } from "@testing-library/react";
+
+// react-i18next: identity t() so the hook renders without an i18n provider.
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (k: string) => k }),
+}));
+
+// react-router-dom: only useNavigate is used by the hook.
+const navigateMock = vi.fn();
+vi.mock("react-router-dom", () => ({
+  useNavigate: () => navigateMock,
+}));
+
+// The auth service is the network boundary; stub login/logout per test.
+const loginMock = vi.fn();
+const logoutMock = vi.fn();
+vi.mock("@/features/auth/services/auth-service", () => ({
+  login: (...args: unknown[]) => loginMock(...args),
+  logout: (...args: unknown[]) => logoutMock(...args),
+  forgotPassword: vi.fn(),
+  passwordReset: vi.fn(),
+  setupWorkspace: vi.fn(),
+  verifyUserToken: vi.fn(),
+}));
+
+vi.mock("@/features/workspace/services/workspace-service.ts", () => ({
+  acceptInvitation: vi.fn(),
+}));
+
+// The offline cache purge is the unit under test — assert it is invoked.
+const clearOfflineCacheMock = vi.fn();
+vi.mock("@/features/offline/clear-offline-cache", () => ({
+  clearOfflineCache: () => clearOfflineCacheMock(),
+}));
+
+// app-route helpers are pure config; provide deterministic values.
+vi.mock("@/lib/app-route.ts", () => ({
+  default: { AUTH: { LOGIN: "/login" }, HOME: "/home" },
+  getPostLoginRedirect: () => "/home",
+}));
+
+// Mantine notifications: avoid touching the DOM-bound notification system.
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: vi.fn() },
+}));
+
+import useAuth from "./use-auth";
+
+beforeEach(() => {
+  navigateMock.mockReset();
+  loginMock.mockReset();
+  loginMock.mockResolvedValue(undefined);
+  logoutMock.mockReset();
+  logoutMock.mockResolvedValue(undefined);
+  clearOfflineCacheMock.mockReset();
+  clearOfflineCacheMock.mockResolvedValue(undefined);
+});
+
+describe("useAuth.handleSignIn", () => {
+  it("clears the offline cache BEFORE logging in (cross-user leak guard)", async () => {
+    const order: string[] = [];
+    clearOfflineCacheMock.mockImplementation(async () => {
+      order.push("clear");
+    });
+    loginMock.mockImplementation(async () => {
+      order.push("login");
+    });
+
+    const { result } = renderHook(() => useAuth());
+    await act(async () => {
+      await result.current.signIn({ email: "b@x", password: "pw" } as any);
+    });
+
+    expect(clearOfflineCacheMock).toHaveBeenCalledTimes(1);
+    expect(loginMock).toHaveBeenCalledTimes(1);
+    // The purge must run before the new session's login resolves.
+    expect(order).toEqual(["clear", "login"]);
+    expect(navigateMock).toHaveBeenCalledWith("/home");
+  });
+
+  it("does not block sign-in when the cache purge throws (best-effort)", async () => {
+    clearOfflineCacheMock.mockRejectedValue(new Error("idb unavailable"));
+
+    const { result } = renderHook(() => useAuth());
+    await act(async () => {
+      await result.current.signIn({ email: "b@x", password: "pw" } as any);
+    });
+
+    // Login still proceeds despite the cleanup failure.
+    expect(loginMock).toHaveBeenCalledTimes(1);
+    expect(navigateMock).toHaveBeenCalledWith("/home");
+  });
+});
+
+describe("useAuth.handleLogout", () => {
+  const replaceMock = vi.fn();
+  let originalLocation: Location;
+
+  beforeEach(() => {
+    replaceMock.mockReset();
+    // window.location.replace is the post-logout redirect. jsdom's real `replace`
+    // is a non-configurable method that warns "not implemented", so swap the
+    // whole location object for one whose `replace` we can capture.
+    originalLocation = window.location;
+    Object.defineProperty(window, "location", {
+      configurable: true,
+      writable: true,
+      value: { replace: replaceMock },
+    });
+  });
+
+  afterEach(() => {
+    Object.defineProperty(window, "location", {
+      configurable: true,
+      writable: true,
+      value: originalLocation,
+    });
+  });
+
+  it("purges the offline cache exactly once BEFORE redirecting (cross-user leak guard)", async () => {
+    const order: string[] = [];
+    clearOfflineCacheMock.mockImplementation(async () => {
+      order.push("clear");
+    });
+    replaceMock.mockImplementation((url: string) => {
+      order.push(`replace:${url}`);
+    });
+
+    const { result } = renderHook(() => useAuth());
+    await act(async () => {
+      await result.current.logout();
+    });
+
+    expect(clearOfflineCacheMock).toHaveBeenCalledTimes(1);
+    // Purge must complete before the redirect (which would otherwise interrupt
+    // the async cleanup).
+    expect(order).toEqual(["clear", "replace:/login?logout=1"]);
+  });
+
+  it("still redirects when the cache purge throws (best-effort, never blocks logout)", async () => {
+    clearOfflineCacheMock.mockRejectedValue(new Error("idb unavailable"));
+
+    const { result } = renderHook(() => useAuth());
+    await act(async () => {
+      await result.current.logout();
+    });
+
+    // The thrown purge error is swallowed and the redirect still fires.
+    expect(clearOfflineCacheMock).toHaveBeenCalledTimes(1);
+    expect(replaceMock).toHaveBeenCalledTimes(1);
+    expect(replaceMock).toHaveBeenCalledWith("/login?logout=1");
+  });
+});

apps/client/src/features/auth/hooks/use-auth.ts

@@ -23,6 +23,7 @@ import { acceptInvitation } from "@/features/workspace/services/workspace-servic
 import APP_ROUTE, { getPostLoginRedirect } from "@/lib/app-route.ts";
 import { RESET } from "jotai/utils";
 import { useTranslation } from "react-i18next";
+import { clearOfflineCache } from "@/features/offline/clear-offline-cache";
 
 export default function useAuth() {
   const { t } = useTranslation();
@@ -33,6 +34,20 @@ export default function useAuth() {
   const handleSignIn = async (data: ILogin) => {
     setIsLoading(true);
 
+    // Purge any previous user's offline data BEFORE signing in (mirrors logout).
+    // On a shared/kiosk device the prior session may have ended WITHOUT an
+    // explicit logout (cookie/JWT expiry, tab close, force-quit), leaving user
+    // A's persisted query cache (gitmost-rq-cache) and Yjs page bodies
+    // (page.<id>) in IndexedDB. Without this purge user B would briefly read A's
+    // cached currentUser/pages/comments on first render (UserProvider serves the
+    // cached user) and A's page bodies would stay readable offline. Best-effort:
+    // never block sign-in on cache cleanup.
+    try {
+      await clearOfflineCache();
+    } catch {
+      // best-effort: never block sign-in on cache cleanup
+    }
+
     try {
       await login(data);
       setIsLoading(false);
@@ -123,6 +138,13 @@ export default function useAuth() {
   const handleLogout = async () => {
     setCurrentUser(RESET);
     await logout();
+    // Purge the previous user's offline data while the page is still alive —
+    // window.location.replace below would otherwise interrupt async cleanup.
+    try {
+      await clearOfflineCache();
+    } catch {
+      // best-effort: never block logout on cache cleanup
+    }
     window.location.replace(`${APP_ROUTE.AUTH.LOGIN}?logout=1`);
   };
 

apps/client/src/features/auth/queries/auth-query.test.ts

@@ -0,0 +1,43 @@
+import { describe, it, expect } from "vitest";
+import { AxiosError } from "axios";
+import { collabTokenRetry } from "./auth-query";
+
+// Regression for the offline white-screen (#237/#238): offline the collab-token
+// POST rejects as an axios NETWORK error (isAxiosError === true but
+// error.response === undefined). The old predicate read `error.response.status`
+// without a guard and threw an uncaught TypeError inside the React Query retryer
+// BEFORE React mounted, blanking the whole app. The predicate must stay total.
+describe("collabTokenRetry", () => {
+  it("does NOT throw and returns a retryable value for a network error with no response (offline)", () => {
+    // An axios error with no `response` is exactly the offline/network-failure shape.
+    const networkError = new AxiosError("Network Error");
+    expect(networkError.response).toBeUndefined();
+
+    let result: boolean | number = false;
+    expect(() => {
+      result = collabTokenRetry(0, networkError);
+    }).not.toThrow();
+    // Network failures stay retryable (truthy), matching the original intent.
+    expect(result).toBe(true);
+  });
+
+  it("returns false (no retry) for a real 404 response", () => {
+    const notFound = new AxiosError("Not Found");
+    notFound.response = { status: 404 } as AxiosError["response"];
+    expect(collabTokenRetry(0, notFound)).toBe(false);
+  });
+
+  it("retries for a non-404 response (e.g. 500)", () => {
+    const serverError = new AxiosError("Server Error");
+    serverError.response = { status: 500 } as AxiosError["response"];
+    expect(collabTokenRetry(0, serverError)).toBe(true);
+  });
+
+  it("does not throw and retries for a non-axios error", () => {
+    let result: boolean | number = false;
+    expect(() => {
+      result = collabTokenRetry(0, new Error("boom"));
+    }).not.toThrow();
+    expect(result).toBe(true);
+  });
+});

apps/client/src/features/auth/queries/auth-query.tsx

@@ -3,6 +3,27 @@ import { getCollabToken, verifyUserToken } from "../services/auth-service";
 import { ICollabToken, IVerifyUserToken } from "../types/auth.types";
 import { isAxiosError } from "axios";
 
+/**
+ * Retry predicate for the collab-token query.
+ *
+ * Offline (or any network failure) the POST rejects as an axios NETWORK error:
+ * `isAxiosError(error) === true` but `error.response === undefined`. Reading
+ * `error.response.status` without a guard threw an uncaught TypeError inside the
+ * React Query retryer BEFORE React mounted, white-screening the whole app on an
+ * offline cold boot (#237/#238). Optional-chaining `error.response?.status`
+ * keeps the predicate total: a network error (no response) is retryable, a real
+ * 404 is not. Extracted (and exported) so it can be unit-tested in isolation.
+ */
+export function collabTokenRetry(
+  _failureCount: number,
+  error: Error,
+): boolean {
+  if (isAxiosError(error) && error.response?.status === 404) {
+    return false;
+  }
+  return true;
+}
+
 export function useVerifyUserTokenQuery(
   verify: IVerifyUserToken,
 ): UseQueryResult<any, Error> {
@@ -22,13 +43,7 @@ export function useCollabToken(): UseQueryResult<ICollabToken, Error> {
     //refetchInterval: 12 * 60 * 60 * 1000, // 12hrs
     //refetchIntervalInBackground: true,
     refetchOnMount: true,
-    //@ts-ignore
-    retry: (failureCount, error) => {
-      if (isAxiosError(error) && error.response.status === 404) {
-        return false;
-      }
-      return 10;
-    },
+    retry: collabTokenRetry,
     retryDelay: (retryAttempt) => {
       // Exponential backoff: 5s, 10s, 20s, etc.
       return 5000 * Math.pow(2, retryAttempt - 1);

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

@@ -20,6 +20,7 @@ import { notifications } from "@mantine/notifications";
 import { IPagination } from "@/lib/types.ts";
 import { useTranslation } from "react-i18next";
 import { useEffect, useMemo } from "react";
+import { offlineMutationKeys } from "@/features/offline/offline-mutations";
 
 export const RQ_KEY = (pageId: string) => ["comments", pageId];
 
@@ -60,6 +61,9 @@ export function useCreateCommentMutation() {
   const { t } = useTranslation();
 
   return useMutation<IComment, Error, Partial<IComment>>({
+    // Stable key so a paused comment-create restored from IndexedDB after an
+    // offline reload finds its default mutationFn and is replayed on reconnect.
+    mutationKey: offlineMutationKeys.createComment,
     mutationFn: (data) => createComment(data),
     onSuccess: (newComment) => {
       const cache = queryClient.getQueryData(

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

@@ -10,6 +10,12 @@ export const readOnlyEditorAtom = atom<Editor | null>(null);
 
 export const yjsConnectionStatusAtom = atom<string>("");
 
+// Local (IndexedDB) persistence sync state for the current page's Y.Doc.
+export const isLocalSyncedAtom = atom<boolean>(false);
+
+// Remote (Hocuspocus) sync state for the current page's Y.Doc.
+export const isRemoteSyncedAtom = atom<boolean>(false);
+
 export const showLinkMenuAtom = atom(false);
 
 // Current page's edit mode — initialized from the user's saved preference on

apps/client/src/features/editor/components/common/use-alt-text-control.tsx

@@ -1,16 +1,7 @@
-import React, { useCallback, useEffect, useState } from "react";
 import { Editor } from "@tiptap/react";
-import {
-  ActionIcon,
-  Button,
-  Group,
-  Paper,
-  Text,
-  Textarea,
-  Tooltip,
-} from "@mantine/core";
 import { IconAlt } from "@tabler/icons-react";
 import { useTranslation } from "react-i18next";
+import { useImageTextFieldControl } from "@/features/editor/components/common/use-image-text-field-control.tsx";
 
 const ALT_MAX_LENGTH = 300;
 
@@ -27,113 +18,25 @@ type UseAltTextControlArgs = {
   currentAlt: string;
 };
 
+// Thin wrapper over the shared image text-field popover; see
+// useImageTextFieldControl. The t("...") literals stay here so they remain
+// statically extractable for i18n.
 export function useAltTextControl({
   editor,
   nodeName,
   currentAlt,
 }: UseAltTextControlArgs) {
   const { t } = useTranslation();
-  const [showInput, setShowInput] = useState(false);
-  const [draft, setDraft] = useState("");
-
-  const open = useCallback(() => {
-    setDraft(currentAlt || "");
-    setShowInput(true);
-  }, [currentAlt]);
-
-  useEffect(() => {
-    const handler = () => {
-      if (!editor.isActive(nodeName)) {
-        setShowInput(false);
-      }
-    };
-    editor.on("selectionUpdate", handler);
-    return () => {
-      editor.off("selectionUpdate", handler);
-    };
-  }, [editor, nodeName]);
-
-  const cancel = useCallback(() => {
-    setShowInput(false);
-  }, []);
-
-  const save = useCallback(() => {
-    editor
-      .chain()
-      .focus(undefined, { scrollIntoView: false })
-      .updateAttributes(nodeName, { alt: sanitizeAlt(draft) || undefined })
-      .run();
-    setShowInput(false);
-  }, [editor, nodeName, draft]);
-
-  const onKeyDown = useCallback(
-    (e: React.KeyboardEvent) => {
-      if (e.key === "Enter" && (e.metaKey || e.ctrlKey)) {
-        e.preventDefault();
-        save();
-      } else if (e.key === "Escape") {
-        e.preventDefault();
-        cancel();
-      }
-    },
-    [save, cancel],
-  );
-
-  const button = (
-    <Tooltip position="top" label={t("Alt text")} withinPortal={false}>
-      <ActionIcon
-        onClick={open}
-        size="lg"
-        aria-label={t("Alt text")}
-        variant="subtle"
-      >
-        <IconAlt size={18} />
-      </ActionIcon>
-    </Tooltip>
-  );
-
-  const panel = showInput ? (
-    <Paper
-      withBorder
-      shadow="md"
-      radius={6}
-      p="sm"
-      w={320}
-      style={{ position: "relative", zIndex: 100 }}
-    >
-      <Text size="sm" fw={600} mb={2}>
-        {t("Alt text")}
-      </Text>
-      <Text size="xs" c="dimmed" mb="xs">
-        {t("Describe this for accessibility.")}
-      </Text>
-      <Textarea
-        size="xs"
-        placeholder={t("Add a description")}
-        value={draft}
-        onChange={(e) => setDraft(e.currentTarget.value)}
-        onKeyDown={onKeyDown}
-        autoFocus
-        autosize
-        minRows={2}
-        maxRows={5}
-        maxLength={ALT_MAX_LENGTH}
-      />
-      <Group justify="space-between" align="center" mt="xs" wrap="nowrap">
-        <Text size="xs" c="dimmed">
-          {draft.length}/{ALT_MAX_LENGTH}
-        </Text>
-        <Group gap="xs">
-          <Button size="compact-xs" variant="default" onClick={cancel}>
-            {t("Cancel")}
-          </Button>
-          <Button size="compact-xs" onClick={save}>
-            {t("Save")}
-          </Button>
-        </Group>
-      </Group>
-    </Paper>
-  ) : null;
-
-  return { button, panel, isEditing: showInput };
+  return useImageTextFieldControl({
+    editor,
+    nodeName,
+    currentValue: currentAlt,
+    attrName: "alt",
+    sanitize: sanitizeAlt,
+    maxLength: ALT_MAX_LENGTH,
+    icon: <IconAlt size={18} />,
+    label: t("Alt text"),
+    description: t("Describe this for accessibility."),
+    placeholder: t("Add a description"),
+  });
 }

apps/client/src/features/editor/components/common/use-caption-control.test.ts

@@ -0,0 +1,59 @@
+import { describe, it, expect } from "vitest";
+import { sanitizeCaption } from "@/features/editor/components/common/use-caption-control.tsx";
+
+/**
+ * `sanitizeCaption` = collapse every whitespace run to a single space + trim +
+ * cap at 500 chars. Captions are plain visible text, so this is a softer
+ * normalization than alt-text sanitization.
+ */
+describe("sanitizeCaption", () => {
+  it("trims leading and trailing whitespace", () => {
+    expect(sanitizeCaption("  hello  ")).toBe("hello");
+  });
+
+  it("collapses internal whitespace runs to a single space", () => {
+    expect(sanitizeCaption("a   b    c")).toBe("a b c");
+  });
+
+  it("treats tab, newline and CRLF as whitespace", () => {
+    expect(sanitizeCaption("a\tb")).toBe("a b");
+    expect(sanitizeCaption("a\nb")).toBe("a b");
+    expect(sanitizeCaption("a\r\nb")).toBe("a b");
+    expect(sanitizeCaption("line1\n\n\nline2")).toBe("line1 line2");
+  });
+
+  it("treats unicode whitespace (no-break space) as a separator", () => {
+    // U+00A0 NO-BREAK SPACE is matched by the \s class.
+    expect(sanitizeCaption("a b")).toBe("a b");
+  });
+
+  it("returns empty string for whitespace-only input", () => {
+    expect(sanitizeCaption("   ")).toBe("");
+    expect(sanitizeCaption("")).toBe("");
+  });
+
+  it("keeps a caption at the 500-char limit unchanged", () => {
+    const exact = "x".repeat(500);
+    expect(sanitizeCaption(exact)).toHaveLength(500);
+    expect(sanitizeCaption(exact)).toBe(exact);
+  });
+
+  it("slices a caption longer than 500 chars down to 500", () => {
+    const tooLong = "y".repeat(600);
+    const result = sanitizeCaption(tooLong);
+    expect(result).toHaveLength(500);
+    expect(result).toBe("y".repeat(500));
+  });
+
+  it("collapses whitespace before applying the 500-char cap", () => {
+    // 120 "a  b " groups (600 raw chars) collapse to "a b a b ..." = 479 chars
+    // after trimming the trailing space, which stays under the 500 cap — so only
+    // the collapse is exercised here, no slice. (See the dedicated >500 test
+    // above for the slice boundary.)
+    const input = "a  b ".repeat(120); // lots of double spaces
+    const result = sanitizeCaption(input);
+    expect(result).toHaveLength(479);
+    expect(result.length).toBeLessThanOrEqual(500);
+    expect(result).not.toMatch(/\s{2,}/);
+  });
+});

apps/client/src/features/editor/components/common/use-caption-control.tsx

@@ -0,0 +1,42 @@
+import { Editor } from "@tiptap/react";
+import { IconTextCaption } from "@tabler/icons-react";
+import { useTranslation } from "react-i18next";
+import { useImageTextFieldControl } from "@/features/editor/components/common/use-image-text-field-control.tsx";
+
+const CAPTION_MAX_LENGTH = 500;
+
+// Caption is plain visible text (not a markdown link target like alt), so it is
+// sanitized more softly than alt: collapse runs of whitespace/newlines into a
+// single space and trim, keeping the limit generous.
+export function sanitizeCaption(value: string): string {
+  return value.replace(/\s+/g, " ").trim().slice(0, CAPTION_MAX_LENGTH);
+}
+
+type UseCaptionControlArgs = {
+  editor: Editor;
+  nodeName: string;
+  currentCaption: string;
+};
+
+// Thin wrapper over the shared image text-field popover; see
+// useImageTextFieldControl. The t("...") literals stay here so they remain
+// statically extractable for i18n.
+export function useCaptionControl({
+  editor,
+  nodeName,
+  currentCaption,
+}: UseCaptionControlArgs) {
+  const { t } = useTranslation();
+  return useImageTextFieldControl({
+    editor,
+    nodeName,
+    currentValue: currentCaption,
+    attrName: "caption",
+    sanitize: sanitizeCaption,
+    maxLength: CAPTION_MAX_LENGTH,
+    icon: <IconTextCaption size={18} />,
+    label: t("Caption"),
+    description: t("Shown below the image."),
+    placeholder: t("Add a caption"),
+  });
+}

apps/client/src/features/editor/components/common/use-image-text-field-control.tsx

@@ -0,0 +1,145 @@
+import React, { useCallback, useEffect, useState } from "react";
+import { Editor } from "@tiptap/react";
+import {
+  ActionIcon,
+  Button,
+  Group,
+  Paper,
+  Text,
+  Textarea,
+  Tooltip,
+} from "@mantine/core";
+import { useTranslation } from "react-i18next";
+
+// Shared logic+UI for the image bubble-menu text-field popovers (alt text,
+// caption, ...). Each field is the same popover — an ActionIcon that opens a
+// titled Paper with a counted Textarea and Cancel/Save — differing only in the
+// node attribute it writes, its sanitizer, length cap, icon and labels. The
+// label/description/placeholder are passed already translated so the literal
+// t("...") calls stay in the thin wrappers and remain extractable; the shared
+// Cancel/Save strings are translated here.
+type UseImageTextFieldControlArgs = {
+  editor: Editor;
+  nodeName: string;
+  currentValue: string;
+  attrName: string;
+  sanitize: (value: string) => string;
+  maxLength: number;
+  icon: React.ReactNode;
+  label: string;
+  description: string;
+  placeholder: string;
+};
+
+export function useImageTextFieldControl({
+  editor,
+  nodeName,
+  currentValue,
+  attrName,
+  sanitize,
+  maxLength,
+  icon,
+  label,
+  description,
+  placeholder,
+}: UseImageTextFieldControlArgs) {
+  const { t } = useTranslation();
+  const [showInput, setShowInput] = useState(false);
+  const [draft, setDraft] = useState("");
+
+  const open = useCallback(() => {
+    setDraft(currentValue || "");
+    setShowInput(true);
+  }, [currentValue]);
+
+  useEffect(() => {
+    const handler = () => {
+      if (!editor.isActive(nodeName)) {
+        setShowInput(false);
+      }
+    };
+    editor.on("selectionUpdate", handler);
+    return () => {
+      editor.off("selectionUpdate", handler);
+    };
+  }, [editor, nodeName]);
+
+  const cancel = useCallback(() => {
+    setShowInput(false);
+  }, []);
+
+  const save = useCallback(() => {
+    editor
+      .chain()
+      .focus(undefined, { scrollIntoView: false })
+      .updateAttributes(nodeName, { [attrName]: sanitize(draft) || undefined })
+      .run();
+    setShowInput(false);
+  }, [editor, nodeName, attrName, sanitize, draft]);
+
+  const onKeyDown = useCallback(
+    (e: React.KeyboardEvent) => {
+      if (e.key === "Enter" && (e.metaKey || e.ctrlKey)) {
+        e.preventDefault();
+        save();
+      } else if (e.key === "Escape") {
+        e.preventDefault();
+        cancel();
+      }
+    },
+    [save, cancel],
+  );
+
+  const button = (
+    <Tooltip position="top" label={label} withinPortal={false}>
+      <ActionIcon onClick={open} size="lg" aria-label={label} variant="subtle">
+        {icon}
+      </ActionIcon>
+    </Tooltip>
+  );
+
+  const panel = showInput ? (
+    <Paper
+      withBorder
+      shadow="md"
+      radius={6}
+      p="sm"
+      w={320}
+      style={{ position: "relative", zIndex: 100 }}
+    >
+      <Text size="sm" fw={600} mb={2}>
+        {label}
+      </Text>
+      <Text size="xs" c="dimmed" mb="xs">
+        {description}
+      </Text>
+      <Textarea
+        size="xs"
+        placeholder={placeholder}
+        value={draft}
+        onChange={(e) => setDraft(e.currentTarget.value)}
+        onKeyDown={onKeyDown}
+        autoFocus
+        autosize
+        minRows={2}
+        maxRows={5}
+        maxLength={maxLength}
+      />
+      <Group justify="space-between" align="center" mt="xs" wrap="nowrap">
+        <Text size="xs" c="dimmed">
+          {draft.length}/{maxLength}
+        </Text>
+        <Group gap="xs">
+          <Button size="compact-xs" variant="default" onClick={cancel}>
+            {t("Cancel")}
+          </Button>
+          <Button size="compact-xs" onClick={save}>
+            {t("Save")}
+          </Button>
+        </Group>
+      </Group>
+    </Paper>
+  ) : null;
+
+  return { button, panel, isEditing: showInput };
+}

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

@@ -23,6 +23,7 @@ import { useTranslation } from "react-i18next";
 import { getFileUrl } from "@/lib/config.ts";
 import { uploadImageAction } from "@/features/editor/components/image/upload-image-action.tsx";
 import { useAltTextControl } from "@/features/editor/components/common/use-alt-text-control.tsx";
+import { useCaptionControl } from "@/features/editor/components/common/use-caption-control.tsx";
 import classes from "../common/toolbar-menu.module.css";
 
 export function ImageMenu({ editor }: EditorMenuProps) {
@@ -47,6 +48,7 @@ export function ImageMenu({ editor }: EditorMenuProps) {
         isFloatRight: ctx.editor.isActive("image", { align: "floatRight" }),
         src: imageAttrs?.src || null,
         alt: imageAttrs?.alt || "",
+        caption: imageAttrs?.caption || "",
       };
     },
   });
@@ -168,6 +170,16 @@ export function ImageMenu({ editor }: EditorMenuProps) {
     currentAlt: editorState?.alt || "",
   });
 
+  const {
+    button: captionButton,
+    panel: captionPanel,
+    isEditing: isEditingCaption,
+  } = useCaptionControl({
+    editor,
+    nodeName: "image",
+    currentCaption: editorState?.caption || "",
+  });
+
   return (
     <BaseBubbleMenu
       editor={editor}
@@ -183,6 +195,8 @@ export function ImageMenu({ editor }: EditorMenuProps) {
     >
       {isEditingAlt ? (
         altTextPanel
+      ) : isEditingCaption ? (
+        captionPanel
       ) : (
         <div className={classes.toolbar}>
         <Tooltip position="top" label={t("Align left")} withinPortal={false}>
@@ -249,6 +263,8 @@ export function ImageMenu({ editor }: EditorMenuProps) {
 
         {altTextButton}
 
+        {captionButton}
+
         <div className={classes.divider} />
 
         <Tooltip position="top" label={t("Download")} withinPortal={false}>

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

@@ -9,7 +9,9 @@ import { useTranslation } from "react-i18next";
 export default function ImageView(props: NodeViewProps) {
   const { t } = useTranslation();
   const { editor, node, selected } = props;
-  const { src, width, align, alt, aspectRatio, placeholder } = node.attrs;
+  const { src, width, align, alt, caption, aspectRatio, placeholder } =
+    node.attrs;
+  const captionText = (caption || "").trim();
   const alignClass = useMemo(() => {
     if (align === "left") return "alignLeft";
     if (align === "right") return "alignRight";
@@ -29,6 +31,7 @@ export default function ImageView(props: NodeViewProps) {
 
   return (
     <NodeViewWrapper data-drag-handle>
+      <figure style={{ margin: 0 }}>
       <div
         className={clsx(
           selected && "ProseMirror-selectednode",
@@ -66,6 +69,15 @@ export default function ImageView(props: NodeViewProps) {
           </Group>
         )}
       </div>
+      {captionText && (
+        <Text
+          component="figcaption"
+          className="image-caption"
+        >
+          {captionText}
+        </Text>
+      )}
+      </figure>
     </NodeViewWrapper>
   );
 }

apps/client/src/features/editor/contexts/editor-providers-context.tsx

@@ -0,0 +1,21 @@
+import { createContext, useContext } from "react";
+import type { HocuspocusProvider } from "@hocuspocus/provider";
+import type * as Y from "yjs";
+
+// Shared collaboration providers lifted above the title/body editors so that
+// both siblings bind to the SAME Y.Doc and HocuspocusProvider. The title lives
+// in a dedicated 'title' fragment of the same doc as the body.
+export interface EditorProvidersContextValue {
+  ydoc: Y.Doc;
+  remote: HocuspocusProvider;
+  providersReady: boolean;
+}
+
+export const EditorProvidersContext =
+  createContext<EditorProvidersContextValue | null>(null);
+
+// Returns the shared providers, or null when rendered outside of a provider.
+// Consumers must be null-safe (the body editor falls back to a non-collab mode).
+export function useEditorProviders(): EditorProvidersContextValue | null {
+  return useContext(EditorProvidersContext);
+}

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

@@ -125,6 +125,7 @@ import { countWords } from "alfaaz";
 import AutoJoiner from "@/features/editor/extensions/autojoiner.ts";
 import GlobalDragHandle from "@/features/editor/extensions/drag-handle.ts";
 import { CleanStyles } from "@/features/editor/extensions/clean-styles.ts";
+import { IntentionalClear } from "@/features/editor/extensions/intentional-clear.ts";
 
 const lowlight = createLowlight(common);
 lowlight.register("mermaid", plaintext);
@@ -493,4 +494,10 @@ export const collabExtensions: CollabExtensions = (provider, user) => [
       color: randomElement(userColors),
     },
   }),
+  // #251 — emit an intentional-clear signal to the server when the user
+  // deliberately empties the page, so the #248 store-side empty-guard lets that
+  // one clear through while still blocking accidental empties.
+  IntentionalClear.configure({
+    provider,
+  }),
 ];

apps/client/src/features/editor/extensions/intentional-clear.test.ts

@@ -0,0 +1,120 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { Editor } from "@tiptap/core";
+import { Document } from "@tiptap/extension-document";
+import { Paragraph } from "@tiptap/extension-paragraph";
+import { Text } from "@tiptap/extension-text";
+import { ySyncPluginKey } from "@tiptap/y-tiptap";
+import {
+  IntentionalClear,
+  INTENTIONAL_CLEAR_MESSAGE_TYPE,
+} from "./intentional-clear";
+
+/**
+ * #251 — the intentional-clear signal is driven through the REAL editor path:
+ * a fresh Editor with the IntentionalClear extension, a fake provider that
+ * records sendStateless, and the actual select-all + delete command the user's
+ * keystroke runs. No hand-poke of any flag.
+ */
+describe("IntentionalClear extension", () => {
+  let sendStateless: ReturnType<typeof vi.fn>;
+
+  const makeEditor = (content: unknown) =>
+    new Editor({
+      extensions: [
+        Document,
+        Paragraph,
+        Text,
+        IntentionalClear.configure({
+          // Minimal provider stand-in: only sendStateless is exercised.
+          provider: { sendStateless } as any,
+        }),
+      ],
+      content: content as any,
+    });
+
+  beforeEach(() => {
+    sendStateless = vi.fn();
+  });
+
+  it("emits the clear signal when a user empties a non-empty doc (select-all + delete)", () => {
+    const editor = makeEditor({
+      type: "doc",
+      content: [
+        { type: "paragraph", content: [{ type: "text", text: "hello world" }] },
+      ],
+    });
+
+    // The exact command path a select-all + Delete keystroke dispatches.
+    editor.chain().selectAll().deleteSelection().run();
+
+    expect(sendStateless).toHaveBeenCalledTimes(1);
+    const payload = JSON.parse(sendStateless.mock.calls[0][0]);
+    expect(payload).toEqual({ type: INTENTIONAL_CLEAR_MESSAGE_TYPE });
+
+    editor.destroy();
+  });
+
+  it("does NOT emit when typing into an empty doc (no non-empty → empty transition)", () => {
+    const editor = makeEditor({ type: "doc", content: [{ type: "paragraph" }] });
+
+    editor.chain().insertContent("typed text").run();
+
+    expect(sendStateless).not.toHaveBeenCalled();
+    editor.destroy();
+  });
+
+  it("does NOT emit on an edit that leaves the doc non-empty", () => {
+    const editor = makeEditor({
+      type: "doc",
+      content: [
+        { type: "paragraph", content: [{ type: "text", text: "keep me" }] },
+      ],
+    });
+
+    editor.chain().insertContent(" more").run();
+
+    expect(sendStateless).not.toHaveBeenCalled();
+    editor.destroy();
+  });
+
+  it("does NOT emit when a REMOTE/merge (change-origin) transaction empties the doc", () => {
+    // This pins the CENTRAL #248 protection: only a LOCAL user edit may emit the
+    // intentional-clear signal. An emptiness arriving from another client, a bad
+    // merge, or an emptied transclusion is applied as a y-sync transaction tagged
+    // with the ySyncPluginKey meta, which `isChangeOrigin` detects. The extension
+    // must early-return on it and NOT punch the empty write through the server
+    // guard.
+    const editor = makeEditor({
+      type: "doc",
+      content: [
+        { type: "paragraph", content: [{ type: "text", text: "remote content" }] },
+      ],
+    });
+
+    // Build a transaction that empties the non-empty doc and tag it exactly the
+    // way y-tiptap tags a remote y-sync update: `tr.setMeta(ySyncPluginKey,
+    // { isChangeOrigin: true })` (see @tiptap/y-tiptap sync-plugin). This makes
+    // the real `isChangeOrigin(tr)` predicate return true — not a stand-in.
+    const { state } = editor;
+    const tr = state.tr
+      .delete(0, state.doc.content.size)
+      .setMeta(ySyncPluginKey, { isChangeOrigin: true });
+    editor.view.dispatch(tr);
+
+    // The transaction really emptied the doc (became the single empty paragraph)…
+    expect(editor.state.doc.textContent).toBe("");
+    // …yet because it is change-origin, no signal is emitted.
+    expect(sendStateless).not.toHaveBeenCalled();
+    editor.destroy();
+  });
+
+  it("does NOT emit when the doc was already empty", () => {
+    const editor = makeEditor({ type: "doc", content: [{ type: "paragraph" }] });
+
+    // Selecting all + delete on an already-empty doc is a no-op transition.
+    editor.chain().selectAll().deleteSelection().run();
+
+    expect(sendStateless).not.toHaveBeenCalled();
+    editor.destroy();
+  });
+});

apps/client/src/features/editor/extensions/intentional-clear.ts

@@ -0,0 +1,94 @@
+import { Extension } from "@tiptap/core";
+import { isChangeOrigin } from "@tiptap/extension-collaboration";
+import type { Node as PMNode } from "@tiptap/pm/model";
+import type { HocuspocusProvider } from "@hocuspocus/provider";
+
+/**
+ * Stateless message type sent to the server when a user deliberately clears a
+ * page to empty. Kept in one place so the client emitter and the server
+ * consumer (PersistenceExtension.onStateless) agree on the wire format.
+ */
+export const INTENTIONAL_CLEAR_MESSAGE_TYPE = "intentional-clear";
+
+export interface IntentionalClearOptions {
+  /** The collab provider used to send the stateless clear signal. */
+  provider: HocuspocusProvider | null;
+}
+
+/**
+ * A "document is empty" check that mirrors the server's `isEmptyParagraphDoc`
+ * (collaboration.util.ts): exactly one top-level paragraph with no inline
+ * content. After a select-all + delete TipTap leaves precisely this shape, so
+ * matching it here keeps the client signal aligned with the server guard that
+ * consumes it.
+ */
+function isEmptyParagraphDoc(doc: PMNode): boolean {
+  if (doc.childCount !== 1) return false;
+  const child = doc.firstChild;
+  return (
+    child !== null &&
+    child !== undefined &&
+    child.type.name === "paragraph" &&
+    child.content.size === 0
+  );
+}
+
+/**
+ * #251 — intentional-clear signal.
+ *
+ * The server's #248 store-side empty-guard unconditionally refuses to overwrite
+ * non-empty persisted content with an empty document, because a momentarily
+ * empty live Y.Doc (a glitch, a bad merge, an emptying transclusion) is
+ * indistinguishable from a real clear *at the store layer*. That protection is
+ * correct, but it also blocks a user who genuinely wants to empty the page.
+ *
+ * This extension supplies the missing distinction. It watches LOCAL, user-driven
+ * transactions and, the moment one reduces a non-empty document to the empty
+ * single-paragraph shape, it sends a hocuspocus stateless message to the server.
+ * The server records a short-lived, single-use "intentional clear pending" flag
+ * for this document that the next (debounced) onStoreDocument consumes to let
+ * that one empty write through the guard.
+ *
+ * What counts as an intentional clear (precise definition):
+ *  - the transaction actually changed the document (`docChanged`), AND
+ *  - it is a LOCAL user edit, not a remote collab application — remote y-sync
+ *    transactions are tagged and filtered out via `isChangeOrigin`, so an
+ *    emptiness that arrives from another client / a merge never emits a signal,
+ *    AND
+ *  - the document was non-empty before the transaction and is the empty
+ *    single-paragraph doc after it.
+ *
+ * This is exactly the select-all + Delete / Backspace (or any local command that
+ * empties the doc, e.g. clearContent) keystroke path. A transient/programmatic
+ * empty serialization that the server might see on the wire does NOT come with
+ * this signal, so the guard still blocks it.
+ */
+export const IntentionalClear = Extension.create<IntentionalClearOptions>({
+  name: "intentionalClear",
+
+  addOptions() {
+    return {
+      provider: null,
+    };
+  },
+
+  onTransaction({ transaction }) {
+    if (!transaction.docChanged) return;
+    // Only react to local user edits. Remote collaboration steps (and other
+    // y-sync-applied changes) carry the change origin and must never be treated
+    // as an intentional clear, otherwise a remote/merge-induced emptiness would
+    // punch through the server guard.
+    if (isChangeOrigin(transaction)) return;
+
+    const becameEmpty =
+      !isEmptyParagraphDoc(transaction.before) &&
+      isEmptyParagraphDoc(transaction.doc);
+    if (!becameEmpty) return;
+
+    // The server reads the originating document from the connection, so the
+    // payload only needs to declare intent — it cannot target another document.
+    this.options.provider?.sendStateless(
+      JSON.stringify({ type: INTENTIONAL_CLEAR_MESSAGE_TYPE }),
+    );
+  },
+});

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

@@ -34,6 +34,8 @@ import {
 } from "@/features/editor/atoms/editor-atoms.ts";
 import { DictationGroup } from "@/features/editor/components/fixed-toolbar/groups/dictation-group";
 import { GenerateTitleGroup } from "@/features/editor/components/fixed-toolbar/groups/generate-title-group";
+import { usePageCollabProviders } from "@/features/editor/hooks/use-page-collab-providers";
+import { EditorProvidersContext } from "@/features/editor/contexts/editor-providers-context";
 
 const MemoizedTitleEditor = React.memo(TitleEditor);
 const MemoizedPageEditor = React.memo(PageEditor);
@@ -80,16 +82,24 @@ export function FullEditor({
   // AI title generation is gated by the general AI chat flag (the same toggle
   // that enables the chat agent); the server enforces it too (#199).
   const isTitleGenEnabled = workspace?.settings?.ai?.chat === true;
-  const fullPageWidth = user.settings?.preferences?.fullPageWidth;
+  // `user` can momentarily be null during logout teardown (the currentUser atom
+  // is reset before this subtree unmounts). Optional-chain every access so the
+  // teardown render does not throw "Cannot read properties of null (reading
+  // 'settings')".
+  const fullPageWidth = user?.settings?.preferences?.fullPageWidth;
   const editorToolbarEnabled =
-    user.settings?.preferences?.editorToolbar ?? false;
+    user?.settings?.preferences?.editorToolbar ?? false;
   const [currentPageEditMode, setCurrentPageEditMode] = useAtom(
     currentPageEditModeAtom,
   );
   const userPageEditMode =
-    user.settings?.preferences?.pageEditMode ?? PageEditMode.Edit;
+    user?.settings?.preferences?.pageEditMode ?? PageEditMode.Edit;
   const isEditMode = currentPageEditMode === PageEditMode.Edit;
 
+  // Single shared Y.Doc + HocuspocusProvider for both the title and body
+  // editors (title lives in the 'title' fragment of the same doc).
+  const { ydoc, remote, providersReady } = usePageCollabProviders(pageId);
+
   // Apply the user's saved preference only once on initial load, not on every
   // page navigation — so the mode sticks across navigations within a session.
   useEffect(() => {
@@ -110,28 +120,32 @@ export function FullEditor({
       )}
       <MemoizedDeletedPageBanner slugId={slugId} />
       <MemoizedTemporaryNoteBanner slugId={slugId} />
-      <MemoizedTitleEditor
-        pageId={pageId}
-        slugId={slugId}
-        title={title}
-        spaceSlug={spaceSlug}
-        editable={editable}
-      />
-      <PageByline
-        pageId={pageId}
-        creator={creator}
-        contributors={contributors}
-        editable={editable}
-        isEditMode={isEditMode}
-        isDictationEnabled={isDictationEnabled}
-        isTitleGenEnabled={isTitleGenEnabled}
-      />
-      <MemoizedPageEditor
-        pageId={pageId}
-        editable={editable}
-        content={content}
-        canComment={canComment}
-      />
+      <EditorProvidersContext.Provider
+        value={ydoc && remote ? { ydoc, remote, providersReady } : null}
+      >
+        <MemoizedTitleEditor
+          pageId={pageId}
+          slugId={slugId}
+          title={title}
+          spaceSlug={spaceSlug}
+          editable={editable}
+        />
+        <PageByline
+          pageId={pageId}
+          creator={creator}
+          contributors={contributors}
+          editable={editable}
+          isEditMode={isEditMode}
+          isDictationEnabled={isDictationEnabled}
+          isTitleGenEnabled={isTitleGenEnabled}
+        />
+        <MemoizedPageEditor
+          pageId={pageId}
+          editable={editable}
+          content={content}
+          canComment={canComment}
+        />
+      </EditorProvidersContext.Provider>
     </Container>
   );
 }

apps/client/src/features/editor/hooks/collab-token.test.ts

@@ -0,0 +1,48 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+// jwt-decode is mocked so we can drive the four token states deterministically
+// (decode success with a chosen exp, or a thrown decode error).
+const decodeMock = vi.hoisted(() => vi.fn());
+vi.mock("jwt-decode", () => ({
+  jwtDecode: decodeMock,
+}));
+
+import { collabTokenNeedsRefresh } from "./collab-token";
+
+const NOW_MS = 1_000_000_000; // fixed "now" in ms (so NOW_MS/1000 seconds)
+
+beforeEach(() => {
+  decodeMock.mockReset();
+});
+
+describe("collabTokenNeedsRefresh", () => {
+  it("returns true when there is no token (fetch a fresh one)", () => {
+    expect(collabTokenNeedsRefresh(undefined, NOW_MS)).toBe(true);
+    // jwtDecode must not even be called for a missing token.
+    expect(decodeMock).not.toHaveBeenCalled();
+  });
+
+  it("returns true when the token is malformed (jwtDecode throws)", () => {
+    decodeMock.mockImplementation(() => {
+      throw new Error("invalid token");
+    });
+    expect(collabTokenNeedsRefresh("garbage", NOW_MS)).toBe(true);
+  });
+
+  it("returns false for a valid, not-yet-expired token (no reconnect)", () => {
+    // exp is in the future relative to NOW.
+    decodeMock.mockReturnValue({ exp: NOW_MS / 1000 + 60 });
+    expect(collabTokenNeedsRefresh("good", NOW_MS)).toBe(false);
+  });
+
+  it("returns true for a valid but expired token (refresh + reconnect)", () => {
+    // exp is in the past relative to NOW.
+    decodeMock.mockReturnValue({ exp: NOW_MS / 1000 - 60 });
+    expect(collabTokenNeedsRefresh("expired", NOW_MS)).toBe(true);
+  });
+
+  it("treats exp exactly equal to now as expired (>= boundary)", () => {
+    decodeMock.mockReturnValue({ exp: NOW_MS / 1000 });
+    expect(collabTokenNeedsRefresh("boundary", NOW_MS)).toBe(true);
+  });
+});

apps/client/src/features/editor/hooks/collab-token.ts

@@ -0,0 +1,26 @@
+import { jwtDecode } from "jwt-decode";
+
+/**
+ * Decide whether a collab token must be refreshed before reconnecting after an
+ * onAuthenticationFailed event. Pure and side-effect free so the four token
+ * states can be unit-tested directly:
+ *   - no token              -> true  (fetch a fresh one and reconnect)
+ *   - undecodable/malformed -> true  (jwtDecode throws -> refresh)
+ *   - valid, not expired    -> false (token is still good; do NOT reconnect)
+ *   - valid, expired        -> true  (refresh + reconnect)
+ *
+ * `nowMs` is injectable for deterministic tests; it defaults to `Date.now()`.
+ */
+export function collabTokenNeedsRefresh(
+  token: string | undefined,
+  nowMs: number = Date.now(),
+): boolean {
+  if (!token) return true;
+  try {
+    const payload = jwtDecode<{ exp: number }>(token);
+    return nowMs / 1000 >= payload.exp;
+  } catch {
+    // malformed/undecodable token -> refresh
+    return true;
+  }
+}

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

@@ -139,7 +139,7 @@ describe("useGeneratePageTitle", () => {
     );
   });
 
-  it("happy path: applies the title, refreshes cache, writes the field, broadcasts", async () => {
+  it("happy path: applies the title, refreshes cache, broadcasts, and does NOT write the editor", async () => {
     const store = createStore();
     const titleEditor = makeTitleEditor();
     store.set(pageEditorAtom as never, makePageEditor("pageA"));
@@ -157,9 +157,11 @@ describe("useGeneratePageTitle", () => {
       title: "Generated Title",
     });
     expect(updatePageDataMock).toHaveBeenCalledWith(PAGE_A);
-    expect(titleEditor.commands.setContent).toHaveBeenCalledWith(
-      "Generated Title",
-    );
+    // The title editor is bound to the Yjs `title` fragment; the server REST
+    // update reseeds that fragment and the reseed reaches the bound editor on
+    // its own. Writing here too would double/garble the title, so the hook must
+    // NOT touch the editor (regression guard for the Yjs duplication trap).
+    expect(titleEditor.commands.setContent).not.toHaveBeenCalled();
     expect(localEmitMock).toHaveBeenCalled();
     expect(emitMock).toHaveBeenCalled();
     expect(notificationsShowMock).toHaveBeenCalledWith(
@@ -167,7 +169,7 @@ describe("useGeneratePageTitle", () => {
     );
   });
 
-  it("does NOT write the visible title field when the user navigated away during generation", async () => {
+  it("keeps the DB write keyed by the captured pageId and still broadcasts after navigation", async () => {
     const store = createStore();
     const titleEditor = makeTitleEditor(); // persistent across navigation
     store.set(pageEditorAtom as never, makePageEditor("pageA"));
@@ -203,55 +205,9 @@ describe("useGeneratePageTitle", () => {
       pageId: "pageA",
       title: "Generated Title",
     });
-    // ...but we must NOT stamp page A's title into page B's visible field.
+    // ...the hook never writes the editor regardless of navigation...
     expect(titleEditor.commands.setContent).not.toHaveBeenCalled();
-    // The change is still broadcast to other clients.
-    expect(emitMock).toHaveBeenCalled();
-  });
-
-  it("does NOT write the visible title field when the title editor is focused", async () => {
-    const store = createStore();
-    const titleEditor = makeTitleEditor();
-    store.set(pageEditorAtom as never, makePageEditor("pageA"));
-    store.set(titleEditorAtom as never, titleEditor);
-
-    // Resolve generation under our control so we can mark the live title editor
-    // as focused before the post-generation write runs.
-    let resolveTitle!: (t: string) => void;
-    generatePageTitleMock.mockReturnValue(
-      new Promise<string>((res) => {
-        resolveTitle = res;
-      }),
-    );
-    updateTitleMock.mockResolvedValue(PAGE_A);
-    const { result } = setup("pageA", store);
-
-    let pending!: Promise<void>;
-    act(() => {
-      pending = result.current.mutateAsync();
-    });
-
-    // The user clicked into the title field while the model ran — overwriting it
-    // now would clobber what they are actively typing.
-    act(() => {
-      (titleEditor as { isFocused: boolean }).isFocused = true;
-    });
-
-    await act(async () => {
-      resolveTitle("Generated Title");
-      await pending;
-    });
-
-    // The DB write still persists the value...
-    expect(updateTitleMock).toHaveBeenCalledWith({
-      pageId: "pageA",
-      title: "Generated Title",
-    });
-    expect(updatePageDataMock).toHaveBeenCalledWith(PAGE_A);
-    // ...but the visible field is left alone while it is focused.
-    expect(titleEditor.commands.setContent).not.toHaveBeenCalled();
-    // The change is still broadcast to other clients.
-    expect(localEmitMock).toHaveBeenCalled();
+    // ...and the change is still broadcast to other clients.
     expect(emitMock).toHaveBeenCalled();
   });
 

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

@@ -1,13 +1,9 @@
-import { useRef } from "react";
 import { useMutation } from "@tanstack/react-query";
 import { useAtomValue } from "jotai";
 import { notifications } from "@mantine/notifications";
 import { useTranslation } from "react-i18next";
 import { htmlToMarkdown } from "@docmost/editor-ext";
-import {
-  pageEditorAtom,
-  titleEditorAtom,
-} from "@/features/editor/atoms/editor-atoms.ts";
+import { pageEditorAtom } from "@/features/editor/atoms/editor-atoms.ts";
 import {
   updatePageData,
   useUpdateTitlePageMutation,
@@ -33,18 +29,9 @@ const MAX_CONTENT_CHARS = 20000;
 export function useGeneratePageTitle(pageId: string) {
   const { t } = useTranslation();
   const pageEditor = useAtomValue(pageEditorAtom);
-  const titleEditor = useAtomValue(titleEditorAtom);
   const { mutateAsync: updateTitle } = useUpdateTitlePageMutation();
   const emit = useQueryEmit();
 
-  // The page/title editors come from GLOBAL atoms that re-point when the user
-  // navigates to another page. The mutation below awaits the model for 1-3s, and
-  // its closure captures the editors from the render that started it. Keep a live
-  // reference so the post-generation write targets whatever page is on screen
-  // *now*, not the page the generation was started from.
-  const editorsRef = useRef({ pageEditor, titleEditor });
-  editorsRef.current = { pageEditor, titleEditor };
-
   return useMutation<void, Error, void>({
     mutationFn: async () => {
       if (!pageEditor || pageEditor.isDestroyed) return;
@@ -70,33 +57,15 @@ export function useGeneratePageTitle(pageId: string) {
       const page = await updateTitle({ pageId, title }); // POST /pages/update
       updatePageData(page); // refresh the react-query cache
 
-      // Reflect the new title in the field immediately. The button lives in the
-      // byline, so the title editor is not focused — setContent is safe and stays
-      // undoable through its History extension (Ctrl/Cmd+Z reverts the change).
-      //
-      // Guard against navigation during generation: if the user switched pages
-      // while the model ran, the (persistent) title editor now shows ANOTHER
-      // page, so writing here would drop page A's title into page B's visible
-      // field. page-editor.tsx stamps the live page editor with its pageId
-      // (`editor.storage.pageId`), mirroring TitleEditor's `activePageId !==
-      // pageId` guard — bail the visible write unless that live editor still
-      // belongs to the page this title was generated for. The DB write above is
-      // already correct (keyed by the captured `pageId`), and the broadcast below
-      // still propagates page A's change to other clients.
-      const livePageEditor = editorsRef.current.pageEditor;
-      const liveTitleEditor = editorsRef.current.titleEditor;
-      // `storage.pageId` is stamped untyped in page-editor.tsx's onCreate.
-      const livePageId = (livePageEditor?.storage as { pageId?: string })
-        ?.pageId;
-      const stillOnPage = livePageId === pageId;
-      if (
-        stillOnPage &&
-        liveTitleEditor &&
-        !liveTitleEditor.isDestroyed &&
-        !liveTitleEditor.isFocused
-      ) {
-        liveTitleEditor.commands.setContent(page.title);
-      }
+      // Do NOT write the title into the editor here. The title editor is bound to
+      // the Yjs `title` fragment and Yjs is the source of truth. The server REST
+      // /pages/update reseeds that fragment (writePageTitle → writeTitleFragment,
+      // a full clear+replace) and the reseed reaches the bound title editor on
+      // its own as a remote provider update. The old REST-era setContent here
+      // would race that reseed and double/garble the title (the "Yjs duplication
+      // trap"), so it is intentionally omitted. The DB write above is keyed by
+      // the captured `pageId`, so it stays correct even if the user navigated
+      // away during generation.
 
       // Broadcast to other clients, mirroring TitleEditor.saveTitle's event shape.
       const event: UpdateEvent = {

apps/client/src/features/editor/hooks/use-page-collab-providers.ts

@@ -0,0 +1,189 @@
+import { useEffect, useRef, useState } from "react";
+import { IndexeddbPersistence } from "y-indexeddb";
+import * as Y from "yjs";
+import {
+  HocuspocusProvider,
+  onStatusParameters,
+  WebSocketStatus,
+  HocuspocusProviderWebsocket,
+  onSyncedParameters,
+  onStatelessParameters,
+} from "@hocuspocus/provider";
+import { useAtom, useSetAtom } from "jotai";
+import useCollaborationUrl from "@/features/editor/hooks/use-collaboration-url";
+import {
+  isLocalSyncedAtom,
+  isRemoteSyncedAtom,
+  yjsConnectionStatusAtom,
+} from "@/features/editor/atoms/editor-atoms";
+import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
+import { useDocumentVisibility } from "@mantine/hooks";
+import { useIdle } from "@/hooks/use-idle.ts";
+import { queryClient } from "@/main.tsx";
+import { IPage } from "@/features/page/types/page.types.ts";
+import { useParams } from "react-router-dom";
+import { extractPageSlugId } from "@/lib";
+import { FIVE_MINUTES } from "@/lib/constants.ts";
+import { collabTokenNeedsRefresh } from "@/features/editor/hooks/collab-token";
+import { pageYdocName } from "@/features/editor/page-ydoc-name";
+import { pageKeys } from "@/features/page/queries/page-query";
+
+export interface PageCollabProviders {
+  ydoc: Y.Doc | null;
+  remote: HocuspocusProvider | null;
+  socket: HocuspocusProviderWebsocket | null;
+  providersReady: boolean;
+}
+
+/**
+ * Owns the full collaboration provider lifecycle for a page so that the title
+ * and body editors can share a single Y.Doc + HocuspocusProvider. The behavior
+ * is relocated verbatim from page-editor.tsx: it creates the providers once per
+ * pageId, connects/disconnects on idle/visibility, attaches each render,
+ * destroys on unmount, refreshes the collab token on auth failure, and applies
+ * the onStateless 'page.updated' cache update.
+ */
+export function usePageCollabProviders(pageId: string): PageCollabProviders {
+  const collaborationURL = useCollaborationUrl();
+  const [yjsConnectionStatus, setYjsConnectionStatus] = useAtom(
+    yjsConnectionStatusAtom,
+  );
+  const setIsLocalSyncedAtom = useSetAtom(isLocalSyncedAtom);
+  const setIsRemoteSyncedAtom = useSetAtom(isRemoteSyncedAtom);
+  const { data: collabQuery, refetch: refetchCollabToken } = useCollabToken();
+  // The provider-creating effect runs only once per pageId, so any token read
+  // inside its handlers would be captured STALE (the old token at first render).
+  // Mirror the latest token into a ref the auth-failure handler can read live.
+  const collabTokenRef = useRef<string | undefined>(undefined);
+  useEffect(() => {
+    collabTokenRef.current = collabQuery?.token;
+  }, [collabQuery?.token]);
+  const { isIdle, resetIdle } = useIdle(FIVE_MINUTES, { initialState: false });
+  const documentState = useDocumentVisibility();
+  const { pageSlug } = useParams();
+  const slugId = extractPageSlugId(pageSlug);
+
+  // Providers only created once per pageId
+  const providersRef = useRef<{
+    ydoc: Y.Doc;
+    local: IndexeddbPersistence;
+    remote: HocuspocusProvider;
+    socket: HocuspocusProviderWebsocket;
+  } | null>(null);
+  const [providersReady, setProvidersReady] = useState(false);
+
+  useEffect(() => {
+    if (!providersRef.current) {
+      const documentName = pageYdocName(pageId);
+      const ydoc = new Y.Doc();
+      const local = new IndexeddbPersistence(documentName, ydoc);
+      const socket = new HocuspocusProviderWebsocket({
+        url: collaborationURL,
+      });
+      const onLocalSyncedHandler = () => {
+        setIsLocalSyncedAtom(true);
+      };
+      const onStatusHandler = (event: onStatusParameters) => {
+        setYjsConnectionStatus(event.status);
+      };
+      const onSyncedHandler = (event: onSyncedParameters) => {
+        setIsRemoteSyncedAtom(event.state);
+      };
+      const onStatelessHandler = ({ payload }: onStatelessParameters) => {
+        try {
+          const message = JSON.parse(payload);
+          if (message?.type !== "page.updated" || !message.updatedAt) return;
+          const pageData = queryClient.getQueryData<IPage>(
+            pageKeys.detail(slugId),
+          );
+          if (pageData) {
+            queryClient.setQueryData(pageKeys.detail(slugId), {
+              ...pageData,
+              updatedAt: message.updatedAt,
+              ...(message.lastUpdatedBy && {
+                lastUpdatedBy: message.lastUpdatedBy,
+              }),
+            });
+          }
+        } catch {
+          // ignore unrelated stateless messages
+        }
+      };
+      const onAuthenticationFailedHandler = () => {
+        // Read the token from the ref, not the closed-over `collabQuery`: this
+        // handler is created once and would otherwise decode a stale token after
+        // a refetch. A missing/malformed token must NOT crash the handler —
+        // jwtDecode(undefined) throws — so treat any decode failure as "needs
+        // refresh" and proceed to refetch + reconnect instead of getting stuck.
+        if (!collabTokenNeedsRefresh(collabTokenRef.current)) return;
+        refetchCollabToken().then((result) => {
+          if (result.data?.token) {
+            socket.disconnect();
+            setTimeout(() => {
+              remote.configuration.token = result.data.token;
+              socket.connect();
+            }, 100);
+          }
+        });
+      };
+      const remote = new HocuspocusProvider({
+        websocketProvider: socket,
+        name: documentName,
+        document: ydoc,
+        token: collabQuery?.token,
+        onAuthenticationFailed: onAuthenticationFailedHandler,
+        onStatus: onStatusHandler,
+        onSynced: onSyncedHandler,
+        onStateless: onStatelessHandler,
+      });
+
+      local.on("synced", onLocalSyncedHandler);
+      providersRef.current = { ydoc, socket, local, remote };
+      setProvidersReady(true);
+    } else {
+      setProvidersReady(true);
+    }
+    // Only destroy on final unmount
+    return () => {
+      providersRef.current?.socket.destroy();
+      providersRef.current?.remote.destroy();
+      providersRef.current?.local.destroy();
+      providersRef.current = null;
+      // Reset shared sync state on page change/unmount.
+      setIsLocalSyncedAtom(false);
+      setIsRemoteSyncedAtom(false);
+    };
+  }, [pageId]);
+
+  // Only connect/disconnect on tab/idle, not destroy
+  useEffect(() => {
+    if (!providersReady || !providersRef.current) return;
+    const socket = providersRef.current.socket;
+
+    if (
+      isIdle &&
+      documentState === "hidden" &&
+      yjsConnectionStatus === WebSocketStatus.Connected
+    ) {
+      socket.disconnect();
+      return;
+    }
+    if (
+      documentState === "visible" &&
+      yjsConnectionStatus === WebSocketStatus.Disconnected
+    ) {
+      resetIdle();
+      socket.connect();
+    }
+  }, [isIdle, documentState, providersReady, resetIdle]);
+
+  // Attach here, to make sure the connection gets properly established
+  providersRef.current?.remote.attach();
+
+  return {
+    ydoc: providersRef.current?.ydoc ?? null,
+    remote: providersRef.current?.remote ?? null,
+    socket: providersRef.current?.socket ?? null,
+    providersReady,
+  };
+}

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

@@ -6,16 +6,7 @@ import React, {
   useRef,
   useState,
 } from "react";
-import { IndexeddbPersistence } from "y-indexeddb";
-import * as Y from "yjs";
-import {
-  HocuspocusProvider,
-  onStatusParameters,
-  WebSocketStatus,
-  HocuspocusProviderWebsocket,
-  onSyncedParameters,
-  onStatelessParameters,
-} from "@hocuspocus/provider";
+import { WebSocketStatus } from "@hocuspocus/provider";
 import {
   Editor,
   EditorContent,
@@ -28,13 +19,15 @@ import {
   mainExtensions,
 } from "@/features/editor/extensions/extensions";
 import { useAtom, useAtomValue } from "jotai";
-import useCollaborationUrl from "@/features/editor/hooks/use-collaboration-url";
 import { currentUserAtom } from "@/features/user/atoms/current-user-atom";
 import {
   currentPageEditModeAtom,
+  isLocalSyncedAtom,
+  isRemoteSyncedAtom,
   pageEditorAtom,
   yjsConnectionStatusAtom,
 } from "@/features/editor/atoms/editor-atoms";
+import { useEditorProviders } from "@/features/editor/contexts/editor-providers-context";
 import { asideStateAtom } from "@/components/layouts/global/hooks/atoms/sidebar-atom";
 import {
   activeCommentIdAtom,
@@ -58,10 +51,8 @@ import {
 } from "@/features/editor/components/common/editor-paste-handler.tsx";
 import ExcalidrawMenu from "./components/excalidraw/excalidraw-menu-lazy";
 import DrawioMenu from "./components/drawio/drawio-menu";
-import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
 import SearchAndReplaceDialog from "@/features/editor/components/search-and-replace/search-and-replace-dialog.tsx";
-import { useDebouncedCallback, useDocumentVisibility } from "@mantine/hooks";
-import { useIdle } from "@/hooks/use-idle.ts";
+import { useDebouncedCallback } from "@mantine/hooks";
 import { queryClient } from "@/main.tsx";
 import { IPage } from "@/features/page/types/page.types.ts";
 import { useParams } from "react-router-dom";
@@ -72,9 +63,7 @@ import {
   GitmostInsertRecordingResult,
   gitmostInsertRecordingIntoEditor,
 } from "@/features/editor/gitmost/gitmost-recording.ts";
-import { FIVE_MINUTES } from "@/lib/constants.ts";
 import { PageEditMode } from "@/features/user/types/user.types.ts";
-import { jwtDecode } from "jwt-decode";
 import { searchSpotlight } from "@/features/search/constants.ts";
 import { useEditorScroll } from "./hooks/use-editor-scroll";
 import { EditorLinkMenu } from "@/features/editor/components/link/link-menu";
@@ -103,7 +92,6 @@ export default function PageEditor({
   canComment,
 }: PageEditorProps) {
   const { t } = useTranslation();
-  const collaborationURL = useCollaborationUrl();
   const isComponentMounted = useRef(false);
   const editorRef = useRef<Editor | null>(null);
 
@@ -117,22 +105,10 @@ export default function PageEditor({
   const [, setActiveCommentId] = useAtom(activeCommentIdAtom);
   const [showCommentPopup, setShowCommentPopup] = useAtom(showCommentPopupAtom);
   const [showReadOnlyCommentPopup] = useAtom(showReadOnlyCommentPopupAtom);
-  const [isLocalSynced, setIsLocalSynced] = useState(false);
-  const [isRemoteSynced, setIsRemoteSynced] = useState(false);
   const [yjsConnectionStatus, setYjsConnectionStatus] = useAtom(
     yjsConnectionStatusAtom,
   );
   const menuContainerRef = useRef(null);
-  const { data: collabQuery, refetch: refetchCollabToken } = useCollabToken();
-  // Always holds the latest collab token. The provider effect below runs once
-  // per pageId, so a handler created inside it would otherwise close over a
-  // stale `collabQuery`. Reading the ref gives the current token instead.
-  const collabTokenRef = useRef<string | undefined>(undefined);
-  useEffect(() => {
-    collabTokenRef.current = collabQuery?.token;
-  }, [collabQuery?.token]);
-  const { isIdle, resetIdle } = useIdle(FIVE_MINUTES, { initialState: false });
-  const documentState = useDocumentVisibility();
   const { pageSlug } = useParams();
   const slugId = extractPageSlugId(pageSlug);
   const currentPageEditMode = useAtomValue(currentPageEditModeAtom);
@@ -141,141 +117,27 @@ export default function PageEditor({
     [isComponentMounted],
   );
   const { handleScrollTo } = useEditorScroll({ canScroll });
-  // Providers only created once per pageId
-  const providersRef = useRef<{
-    local: IndexeddbPersistence;
-    remote: HocuspocusProvider;
-    socket: HocuspocusProviderWebsocket;
-  } | null>(null);
-  const [providersReady, setProvidersReady] = useState(false);
 
-  useEffect(() => {
-    if (!providersRef.current) {
-      const documentName = `page.${pageId}`;
-      const ydoc = new Y.Doc();
-      const local = new IndexeddbPersistence(documentName, ydoc);
-      const socket = new HocuspocusProviderWebsocket({
-        url: collaborationURL,
-      });
-      const onLocalSyncedHandler = () => {
-        setIsLocalSynced(true);
-      };
-      const onStatusHandler = (event: onStatusParameters) => {
-        setYjsConnectionStatus(event.status);
-      };
-      const onSyncedHandler = (event: onSyncedParameters) => {
-        setIsRemoteSynced(event.state);
-      };
-      const onStatelessHandler = ({ payload }: onStatelessParameters) => {
-        try {
-          const message = JSON.parse(payload);
-          if (message?.type !== "page.updated" || !message.updatedAt) return;
-          const pageData = queryClient.getQueryData<IPage>(["pages", slugId]);
-          if (pageData) {
-            queryClient.setQueryData(["pages", slugId], {
-              ...pageData,
-              updatedAt: message.updatedAt,
-              ...(message.lastUpdatedBy && {
-                lastUpdatedBy: message.lastUpdatedBy,
-              }),
-            });
-          }
-        } catch {
-          // ignore unrelated stateless messages
-        }
-      };
-      const onAuthenticationFailedHandler = () => {
-        // Read the latest token via the ref (the closure-captured `collabQuery`
-        // may be stale). Guard the decode: a missing or unparseable token must
-        // not throw "Invalid token specified" and should trigger a refresh so
-        // the editor reconnects even when the initial token fetch failed.
-        const token = collabTokenRef.current;
-        let needsRefresh = true; // no/unparseable token -> fetch a fresh one and reconnect
-        if (token) {
-          try {
-            // A token that decodes but lacks a numeric `exp` must be treated as
-            // expired (`Date.now()/1000 >= undefined` is `false`, which would
-            // otherwise skip the reconnect), so refresh on any missing/non-number exp.
-            const exp = jwtDecode<{ exp?: number }>(token).exp;
-            needsRefresh = typeof exp !== "number" || Date.now() / 1000 >= exp;
-          } catch {
-            needsRefresh = true;
-          }
-        }
-        if (!needsRefresh) return;
-        refetchCollabToken().then((result) => {
-          if (result.data?.token) {
-            socket.disconnect();
-            setTimeout(() => {
-              remote.configuration.token = result.data.token;
-              socket.connect();
-            }, 100);
-          }
-        });
-      };
-      const remote = new HocuspocusProvider({
-        websocketProvider: socket,
-        name: documentName,
-        document: ydoc,
-        token: collabQuery?.token,
-        onAuthenticationFailed: onAuthenticationFailedHandler,
-        onStatus: onStatusHandler,
-        onSynced: onSyncedHandler,
-        onStateless: onStatelessHandler,
-      });
-
-      local.on("synced", onLocalSyncedHandler);
-      providersRef.current = { socket, local, remote };
-      setProvidersReady(true);
-    } else {
-      setProvidersReady(true);
-    }
-    // Only destroy on final unmount
-    return () => {
-      providersRef.current?.socket.destroy();
-      providersRef.current?.remote.destroy();
-      providersRef.current?.local.destroy();
-      providersRef.current = null;
-    };
-  }, [pageId]);
-
-  // Only connect/disconnect on tab/idle, not destroy
-  useEffect(() => {
-    if (!providersReady || !providersRef.current) return;
-    const socket = providersRef.current.socket;
-
-    if (
-      isIdle &&
-      documentState === "hidden" &&
-      yjsConnectionStatus === WebSocketStatus.Connected
-    ) {
-      socket.disconnect();
-      return;
-    }
-    if (
-      documentState === "visible" &&
-      yjsConnectionStatus === WebSocketStatus.Disconnected
-    ) {
-      resetIdle();
-      socket.connect();
-    }
-  }, [isIdle, documentState, providersReady, resetIdle]);
-
-  // Attach here, to make sure the connection gets properly established
-  providersRef.current?.remote.attach();
+  // Shared providers + Y.Doc lifted into full-editor via context. The provider
+  // lifecycle (creation, idle/visibility connect, attach, destroy, token
+  // refresh) lives in usePageCollabProviders. Null-safe when rendered without
+  // the context (defensive) — in practice full-editor always provides it.
+  const editorProviders = useEditorProviders();
+  const remote = editorProviders?.remote ?? null;
+  const providersReady = editorProviders?.providersReady ?? false;
+  const isLocalSynced = useAtomValue(isLocalSyncedAtom);
+  const isRemoteSynced = useAtomValue(isRemoteSyncedAtom);
 
   const extensions = useMemo(() => {
-    if (!providersReady || !providersRef.current || !currentUser?.user) {
+    if (!providersReady || !remote || !currentUser?.user) {
       return mainExtensions;
     }
 
-    const remoteProvider = providersRef.current.remote;
-
     return [
       ...mainExtensions,
-      ...collabExtensions(remoteProvider, currentUser?.user),
+      ...collabExtensions(remote, currentUser?.user),
     ];
-  }, [providersReady, currentUser?.user]);
+  }, [providersReady, remote, currentUser?.user]);
 
   const editor = useEditor(
     {
@@ -550,7 +412,7 @@ export default function PageEditor({
             {editor &&
               !editorIsEditable &&
               (editable || canComment) &&
-              providersRef.current && <ReadonlyBubbleMenu editor={editor} />}
+              remote && <ReadonlyBubbleMenu editor={editor} />}
             {showCommentPopup && (
               <CommentDialog editor={editor} pageId={pageId} />
             )}

apps/client/src/features/editor/page-ydoc-name.ts

@@ -0,0 +1,14 @@
+/**
+ * Single source of truth for the IndexedDB / Hocuspocus document name of a
+ * page's collaborative Yjs doc.
+ *
+ * The `page.<id>` convention is shared knowledge across three call sites: the
+ * live editor providers (`use-page-collab-providers`), the offline warm path
+ * (`make-offline`), and the offline purge (`clear-offline-cache`, which matches
+ * the databases to delete by this prefix). Centralizing it here stops those
+ * sites from silently drifting apart.
+ */
+export const PAGE_YDOC_NAME_PREFIX = "page.";
+
+export const pageYdocName = (pageId: string): string =>
+  `${PAGE_YDOC_NAME_PREFIX}${pageId}`;

apps/client/src/features/editor/styles/media.css

@@ -33,6 +33,15 @@
     }
   }
 
+  .image-caption {
+    text-align: center;
+    font-size: 0.875em;
+    color: var(--mantine-color-dimmed);
+    margin-top: 0.4em;
+    line-height: 1.35;
+    word-break: break-word;
+  }
+
   .uploading-text {
     font-size: var(--mantine-font-size-md);
     line-height: var(--mantine-line-height-md);

apps/client/src/features/editor/title-collab.test.ts

@@ -0,0 +1,33 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+// isChangeOrigin is mocked so we can simulate local vs remote/collab-origin
+// transactions without constructing a real ProseMirror/Yjs transaction.
+const isChangeOriginMock = vi.hoisted(() => vi.fn());
+vi.mock("@tiptap/extension-collaboration", () => ({
+  isChangeOrigin: isChangeOriginMock,
+}));
+
+import { shouldPropagateTitleChange } from "./title-collab";
+
+beforeEach(() => {
+  isChangeOriginMock.mockReset();
+});
+
+describe("shouldPropagateTitleChange", () => {
+  it("propagates a genuine local edit (isChangeOrigin false)", () => {
+    isChangeOriginMock.mockReturnValue(false);
+    expect(shouldPropagateTitleChange({ local: true })).toBe(true);
+    expect(isChangeOriginMock).toHaveBeenCalledWith({ local: true });
+  });
+
+  it("skips a remote/collab-origin update (isChangeOrigin true)", () => {
+    isChangeOriginMock.mockReturnValue(true);
+    expect(shouldPropagateTitleChange({ remote: true })).toBe(false);
+  });
+
+  it("propagates when there is no transaction (treated as local)", () => {
+    expect(shouldPropagateTitleChange(undefined)).toBe(true);
+    // isChangeOrigin must not be called for a missing transaction.
+    expect(isChangeOriginMock).not.toHaveBeenCalled();
+  });
+});

apps/client/src/features/editor/title-collab.ts

@@ -0,0 +1,19 @@
+import { isChangeOrigin } from "@tiptap/extension-collaboration";
+
+/**
+ * Whether a TitleEditor `onUpdate` should drive URL + tree propagation.
+ *
+ * Only genuine LOCAL edits propagate. Remote/collab-origin Yjs updates
+ * (detected via `isChangeOrigin`) are skipped so a remote title change is not
+ * re-broadcast back, which would create a feedback loop. A missing transaction
+ * is treated as a local edit (propagate).
+ *
+ * Extracted as a pure helper so the skip decision is unit-testable without
+ * mounting the full collaborative editor.
+ */
+export function shouldPropagateTitleChange(transaction: unknown): boolean {
+  return !(
+    transaction &&
+    isChangeOrigin(transaction as Parameters<typeof isChangeOrigin>[0])
+  );
+}

apps/client/src/features/editor/title-editor.test.tsx

@@ -0,0 +1,87 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen } from "@testing-library/react";
+
+// Drive the fallback-vs-collaborative switch (titleReady = providersReady &&
+// !!ydoc) by controlling what the editor-providers context returns.
+const editorProvidersValue: { ydoc: unknown; providersReady: boolean } = {
+  ydoc: null,
+  providersReady: false,
+};
+vi.mock("@/features/editor/contexts/editor-providers-context", () => ({
+  useEditorProviders: () => editorProvidersValue,
+}));
+
+// Mock the tiptap React bindings so the test does not mount a real editor:
+// useEditor returns a minimal stub and EditorContent renders a marker.
+vi.mock("@tiptap/react", () => ({
+  useEditor: () => ({
+    isInitialized: true,
+    commands: { focus: vi.fn() },
+    setEditable: vi.fn(),
+    getText: () => "",
+  }),
+  EditorContent: () => <div data-testid="collab-editor" />,
+}));
+
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (k: string) => k }),
+}));
+
+const navigateMock = vi.fn();
+vi.mock("react-router-dom", () => ({
+  useNavigate: () => navigateMock,
+}));
+
+vi.mock("@/features/websocket/use-query-emit.ts", () => ({
+  useQueryEmit: () => vi.fn(),
+}));
+
+// page-query transitively imports @/main.tsx; mock it to a pure stub.
+vi.mock("@/features/page/queries/page-query", () => ({
+  updatePageData: vi.fn(),
+}));
+vi.mock("@/main.tsx", () => ({
+  queryClient: { getQueryData: vi.fn(), setQueryData: vi.fn() },
+}));
+
+import { TitleEditor } from "./title-editor";
+
+const baseProps = {
+  pageId: "p1",
+  slugId: "slug-1",
+  title: "My Page Title",
+  spaceSlug: "space",
+  editable: true,
+};
+
+beforeEach(() => {
+  navigateMock.mockReset();
+  editorProvidersValue.ydoc = null;
+  editorProvidersValue.providersReady = false;
+});
+
+describe("TitleEditor fallback vs collaborative switch", () => {
+  it("renders a static <h1> with the title before the shared doc is ready", () => {
+    editorProvidersValue.ydoc = null;
+    editorProvidersValue.providersReady = false;
+
+    render(<TitleEditor {...baseProps} />);
+
+    const heading = screen.getByRole("heading", { level: 1 });
+    expect(heading.textContent).toBe("My Page Title");
+    // The collaborative editor must NOT mount until the doc is ready.
+    expect(screen.queryByTestId("collab-editor")).toBeNull();
+  });
+
+  it("renders the collaborative editor once the shared doc is ready", () => {
+    editorProvidersValue.ydoc = {}; // truthy shared doc
+    editorProvidersValue.providersReady = true;
+
+    render(<TitleEditor {...baseProps} />);
+
+    expect(screen.getByTestId("collab-editor")).toBeDefined();
+    // The static fallback <h1> is gone — Yjs is the single source of truth and
+    // the prop is never seeded into the collaborative editor.
+    expect(screen.queryByRole("heading", { level: 1 })).toBeNull();
+  });
+});

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

@@ -1,5 +1,5 @@
 import "@/features/editor/styles/index.css";
-import React, { useCallback, useEffect, useState } from "react";
+import { useEffect } from "react";
 import { EditorContent, useEditor } from "@tiptap/react";
 import { Document } from "@tiptap/extension-document";
 import { Heading } from "@tiptap/extension-heading";
@@ -11,14 +11,11 @@ import {
   pageEditorAtom,
   titleEditorAtom,
 } from "@/features/editor/atoms/editor-atoms";
-import {
-  updatePageData,
-  useUpdateTitlePageMutation,
-} from "@/features/page/queries/page-query";
+import { pageKeys, updatePageData } from "@/features/page/queries/page-query";
 import { useDebouncedCallback, getHotkeyHandler } from "@mantine/hooks";
 import { useAtom } from "jotai";
-import { useQueryEmit } from "@/features/websocket/use-query-emit.ts";
-import { History } from "@tiptap/extension-history";
+import { Collaboration } from "@tiptap/extension-collaboration";
+import { shouldPropagateTitleChange } from "@/features/editor/title-collab";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
 import { useNavigate } from "react-router-dom";
 import { useTranslation } from "react-i18next";
@@ -28,6 +25,9 @@ import localEmitter from "@/lib/local-emitter.ts";
 import { PageEditMode } from "@/features/user/types/user.types.ts";
 import { searchSpotlight } from "@/features/search/constants.ts";
 import { platformModifierKey } from "@/lib";
+import { useEditorProviders } from "@/features/editor/contexts/editor-providers-context";
+import { queryClient } from "@/main.tsx";
+import { IPage } from "@/features/page/types/page.types.ts";
 
 export interface TitleEditorProps {
   pageId: string;
@@ -45,65 +45,82 @@ export function TitleEditor({
   editable,
 }: TitleEditorProps) {
   const { t } = useTranslation();
-  const { mutateAsync: updateTitlePageMutationAsync } =
-    useUpdateTitlePageMutation();
   const pageEditor = useAtomValue(pageEditorAtom);
   const [, setTitleEditor] = useAtom(titleEditorAtom);
-  const emit = useQueryEmit();
   const navigate = useNavigate();
-  const [activePageId, setActivePageId] = useState(pageId);
   const currentPageEditMode = useAtomValue(currentPageEditModeAtom);
 
-  const titleEditor = useEditor({
-    extensions: [
-      Document.extend({
-        content: "heading",
-      }),
-      Heading.configure({
-        levels: [1],
-      }),
-      Text,
-      Placeholder.configure({
-        placeholder: t("Untitled"),
-        showOnlyWhenEditable: false,
-      }),
-      History.configure({
-        depth: 20,
-      }),
-      EmojiCommand,
-    ],
-    onCreate({ editor }) {
-      if (editor) {
-        // @ts-ignore
-        setTitleEditor(editor);
-        setActivePageId(pageId);
-      }
-    },
-    onUpdate({ editor }) {
-      debounceUpdate();
-    },
-    editable: editable,
-    content: title,
-    immediatelyRender: true,
-    shouldRerenderOnTransaction: false,
-    editorProps: {
-      attributes: {
-        "aria-label": t("Page title"),
+  // Shared Y.Doc (title lives in its own 'title' fragment of the same doc as
+  // the body). Yjs is the source of truth for the title content.
+  const editorProviders = useEditorProviders();
+  const ydoc = editorProviders?.ydoc ?? null;
+  const providersReady = editorProviders?.providersReady ?? false;
+
+  // Until the shared doc is ready, the collaborative editor binds nothing and
+  // would render an empty heading until the Yjs 'title' fragment hydrates. Show
+  // a non-editable static <h1> with the `title` prop in the meantime. The prop
+  // is NEVER fed into the collaborative editor (Yjs stays the single source of
+  // truth — seeding it would duplicate the title).
+  const titleReady = providersReady && !!ydoc;
+
+  const titleEditor = useEditor(
+    {
+      extensions: [
+        Document.extend({
+          content: "heading",
+        }),
+        Heading.configure({
+          levels: [1],
+        }),
+        Text,
+        Placeholder.configure({
+          placeholder: t("Untitled"),
+          showOnlyWhenEditable: false,
+        }),
+        // Bind the title to the dedicated 'title' fragment of the shared doc.
+        // Collaboration also manages undo/redo, so the History extension is
+        // intentionally omitted (it would conflict with Yjs). When the doc is
+        // not ready yet the editor renders empty until the doc arrives.
+        ...(ydoc
+          ? [Collaboration.configure({ document: ydoc, field: "title" })]
+          : []),
+        EmojiCommand,
+      ],
+      onCreate({ editor }) {
+        if (editor) {
+          // @ts-ignore
+          setTitleEditor(editor);
+        }
       },
-      handleDOMEvents: {
-        keydown: (_view, event) => {
-          if (platformModifierKey(event) && event.code === "KeyS") {
-            event.preventDefault();
-            return true;
-          }
-          if (platformModifierKey(event) && event.code === "KeyK") {
-            searchSpotlight.open();
-            return true;
-          }
+      onUpdate({ editor, transaction }) {
+        // Drive URL + tree propagation only on genuine local edits; skip
+        // remote/collab-origin Yjs updates to avoid feedback loops.
+        if (!shouldPropagateTitleChange(transaction)) return;
+        debouncedPropagateTitle(editor.getText());
+      },
+      editable: editable,
+      immediatelyRender: true,
+      shouldRerenderOnTransaction: false,
+      editorProps: {
+        attributes: {
+          "aria-label": t("Page title"),
+        },
+        handleDOMEvents: {
+          keydown: (_view, event) => {
+            if (platformModifierKey(event) && event.code === "KeyS") {
+              event.preventDefault();
+              return true;
+            }
+            if (platformModifierKey(event) && event.code === "KeyK") {
+              searchSpotlight.open();
+              return true;
+            }
+          },
         },
       },
     },
-  });
+    [pageId, ydoc],
+  );
 
   useEffect(() => {
     const anchorId = window.location.hash
@@ -113,59 +130,45 @@ export function TitleEditor({
     navigate(pageSlug, { replace: true });
   }, [title]);
 
-  const saveTitle = useCallback(() => {
-    if (!titleEditor || activePageId !== pageId) return;
-
-    if (
-      titleEditor.getText() === title ||
-      (titleEditor.getText() === "" && title === null)
-    ) {
-      return;
-    }
-
-    updateTitlePageMutationAsync({
-      pageId: pageId,
-      title: titleEditor.getText(),
-    }).then((page) => {
-      const event: UpdateEvent = {
-        operation: "updateOne",
-        spaceId: page.spaceId,
-        entity: ["pages"],
-        id: page.id,
-        payload: {
-          title: page.title,
-          slugId: page.slugId,
-          parentPageId: page.parentPageId,
-          icon: page.icon,
-        },
-      };
-
-      if (page.title !== titleEditor.getText()) return;
-
-      updatePageData(page);
-
-      localEmitter.emit("message", event);
-      emit(event);
+  // On a local title change: update the URL slug and propagate the change to
+  // the live tree/breadcrumbs for online users. No REST round-trip — the title
+  // itself is persisted through Yjs. Offline this simply no-ops the socket
+  // emit and the title syncs on reconnect.
+  const debouncedPropagateTitle = useDebouncedCallback((titleText: string) => {
+    const anchorId = window.location.hash
+      ? window.location.hash.substring(1)
+      : undefined;
+    navigate(buildPageUrl(spaceSlug, slugId, titleText, anchorId), {
+      replace: true,
     });
-  }, [pageId, title, titleEditor]);
 
-  const debounceUpdate = useDebouncedCallback(saveTitle, 500);
+    const page =
+      queryClient.getQueryData<IPage>(pageKeys.detail(slugId)) ??
+      queryClient.getQueryData<IPage>(pageKeys.detail(pageId));
+    if (!page) return;
 
-  useEffect(() => {
-    // Do not overwrite the title while the user is actively editing it. The
-    // server rebroadcasts PAGE_UPDATED to the author too, and that echo can
-    // carry a title that lags behind what the user has just typed; resetting
-    // content from it here would drop in-progress characters and jump the
-    // cursor. Apply external title changes only when the field is not focused.
-    if (
-      titleEditor &&
-      !titleEditor.isDestroyed &&
-      !titleEditor.isFocused &&
-      title !== titleEditor.getText()
-    ) {
-      titleEditor.commands.setContent(title);
-    }
-  }, [pageId, title, titleEditor]);
+    const updatedPage: IPage = { ...page, title: titleText };
+
+    const event: UpdateEvent = {
+      operation: "updateOne",
+      spaceId: page.spaceId,
+      entity: ["pages"],
+      id: page.id,
+      payload: {
+        title: titleText,
+        slugId: page.slugId,
+        parentPageId: page.parentPageId,
+        icon: page.icon,
+      },
+    };
+
+    updatePageData(updatedPage);
+    // Drive the local (same-tab) tree/breadcrumb update. The cross-user tree
+    // refresh is handled server-side: the collab process extracts the renamed
+    // 'title' Yjs fragment and broadcasts a treeUpdate. The previous socket
+    // `emit(event)` here was a no-op (the gateway ignores it) and was removed.
+    localEmitter.emit("message", event);
+  }, 500);
 
   useEffect(() => {
     setTimeout(() => {
@@ -175,13 +178,6 @@ export function TitleEditor({
     }, 300);
   }, [titleEditor]);
 
-  useEffect(() => {
-    return () => {
-      // force-save title on navigation
-      saveTitle();
-    };
-  }, [pageId]);
-
   useEffect(() => {
     if (!titleEditor) return;
     titleEditor.setEditable(editable && currentPageEditMode === PageEditMode.Edit);
@@ -248,16 +244,22 @@ export function TitleEditor({
 
   return (
     <div className="page-title">
-      <EditorContent
-        editor={titleEditor}
-        onKeyDown={(event) => {
-          // First handle the search hotkey
-          getHotkeyHandler([["mod+F", openSearchDialog]])(event);
+      {titleReady ? (
+        <EditorContent
+          editor={titleEditor}
+          onKeyDown={(event) => {
+            // First handle the search hotkey
+            getHotkeyHandler([["mod+F", openSearchDialog]])(event);
 
-          // Then handle other key events
-          handleTitleKeyDown(event);
-        }}
-      />
+            // Then handle other key events
+            handleTitleKeyDown(event);
+          }}
+        />
+      ) : (
+        // Static, non-editable fallback so the title is visible before Yjs
+        // hydrates the 'title' fragment. Not wired into the collaborative editor.
+        <h1>{title}</h1>
+      )}
     </div>
   );
 }

apps/client/src/features/home/components/new-note-button.tsx

@@ -3,6 +3,8 @@ import { IconHourglass, IconPlus } from "@tabler/icons-react";
 import { ReactNode } from "react";
 import { useNavigate } from "react-router-dom";
 import { useTranslation } from "react-i18next";
+import { onlineManager } from "@tanstack/react-query";
+import { notifications } from "@mantine/notifications";
 import { useGetSpacesQuery } from "@/features/space/queries/space-query.ts";
 import { useCreatePageMutation } from "@/features/page/queries/page-query.ts";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
@@ -36,21 +38,39 @@ function CreateNoteButton({
   const createPageMutation = useCreatePageMutation();
 
   const createNote = async (space: ISpace) => {
+    // `spaceId`/`temporary` are accepted by the create-page endpoint but are
+    // not part of the shared `IPageInput` type; cast to satisfy the mutation
+    // signature.
+    const variables = {
+      spaceId: space.id,
+      ...(temporary ? { temporary: true } : {}),
+    } as any;
+
+    if (!onlineManager.isOnline()) {
+      // Offline: the create is PAUSED and queued — its promise will not resolve
+      // until we are back online, so awaiting it here would spin the button
+      // forever. Fire it without awaiting (it persists and replays on reconnect)
+      // and tell the user it was saved offline instead of leaving a dead spinner.
+      createPageMutation.mutate(variables);
+      notifications.show({
+        color: "blue",
+        message: t("You're offline. This note will be created once you reconnect."),
+      });
+      return;
+    }
+
     try {
-      // `spaceId`/`temporary` are accepted by the create-page endpoint but are
-      // not part of the shared `IPageInput` type; cast to satisfy the mutation
-      // signature.
-      const createdPage = await createPageMutation.mutateAsync({
-        spaceId: space.id,
-        ...(temporary ? { temporary: true } : {}),
-      } as any);
+      const createdPage = await createPageMutation.mutateAsync(variables);
       navigate(buildPageUrl(space.slug, createdPage.slugId, createdPage.title));
     } catch {
       // useCreatePageMutation already surfaces a red notification on error.
     }
   };
 
-  const isPending = createPageMutation.isPending;
+  // A paused (offline) mutation stays `isPending`, so gate the spinner on it NOT
+  // being paused — otherwise the button would spin forever after an offline
+  // create. The offline path above gives its own "saved offline" feedback.
+  const isPending = createPageMutation.isPending && !createPageMutation.isPaused;
 
   // Exactly one writable space → create directly, no picker needed.
   if (writableSpaces.length === 1) {

apps/client/src/features/notification/notification.utils.test.ts

@@ -1,5 +1,7 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import i18n from "@/i18n.ts";
 import {
+  formatRelativeTime,
   getTimeGroup,
   groupNotificationsByTime,
 } from "@/features/notification/notification.utils.ts";
@@ -132,3 +134,59 @@ describe("groupNotificationsByTime", () => {
     expect(groupNotificationsByTime([], labels)).toEqual([]);
   });
 });
+
+describe("formatRelativeTime — relative buckets and absolute-date fallback", () => {
+  // Distinct fixed clock for the relative formatter (uses Date.now via `new
+  // Date()`), so the bucket boundaries are deterministic under fake timers.
+  const NOW = new Date("2026-06-15T12:00:00.000Z");
+  const MIN = 60_000;
+
+  beforeEach(() => {
+    vi.setSystemTime(NOW);
+  });
+
+  // ISO string `ms` milliseconds before NOW.
+  function ago(ms: number): string {
+    return new Date(NOW.getTime() - ms).toISOString();
+  }
+
+  it("returns the i18n 'now' label for anything under a minute", () => {
+    expect(formatRelativeTime(ago(0))).toBe(i18n.t("now"));
+    expect(formatRelativeTime(ago(59_000))).toBe(i18n.t("now"));
+  });
+
+  it("crosses into the minutes bucket exactly at 1 minute", () => {
+    expect(formatRelativeTime(ago(MIN - 1000))).toBe(i18n.t("now"));
+    expect(formatRelativeTime(ago(MIN))).toBe("1m");
+    expect(formatRelativeTime(ago(5 * MIN))).toBe("5m");
+    expect(formatRelativeTime(ago(59 * MIN))).toBe("59m");
+  });
+
+  it("crosses into the hours bucket exactly at 60 minutes", () => {
+    expect(formatRelativeTime(ago(60 * MIN - 1000))).toBe("59m");
+    expect(formatRelativeTime(ago(HOUR))).toBe("1h");
+    expect(formatRelativeTime(ago(23 * HOUR))).toBe("23h");
+  });
+
+  it("crosses into the days bucket exactly at 24 hours", () => {
+    expect(formatRelativeTime(ago(24 * HOUR - 1000))).toBe("23h");
+    expect(formatRelativeTime(ago(DAY))).toBe("1d");
+    expect(formatRelativeTime(ago(6 * DAY))).toBe("6d");
+  });
+
+  it("falls back to an absolute short date once >= 7 days old", () => {
+    // 6d -> still relative; 7d -> absolute date (no longer N[mhd], and equal to
+    // the localized short-date of the source timestamp).
+    expect(formatRelativeTime(ago(6 * DAY))).toBe("6d");
+
+    const sevenDaysAgo = ago(7 * DAY);
+    const result = formatRelativeTime(sevenDaysAgo);
+    expect(result).not.toMatch(/^\d+[mhd]$/);
+    expect(result).not.toBe(i18n.t("now"));
+    const expected = new Intl.DateTimeFormat(i18n.language, {
+      month: "short",
+      day: "numeric",
+    }).format(new Date(sevenDaysAgo));
+    expect(result).toBe(expected);
+  });
+});

apps/client/src/features/offline/clear-offline-cache.test.ts

@@ -0,0 +1,107 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+
+// vi.mock factories are hoisted above imports, so the spies they reference must
+// be declared via vi.hoisted (also hoisted). These are inspected by assertions.
+const h = vi.hoisted(() => ({
+  clear: vi.fn(),
+  del: vi.fn(),
+}));
+
+// The module under test imports the app entry at load time — it must be mocked.
+vi.mock("@/main.tsx", () => ({
+  queryClient: { clear: h.clear },
+}));
+vi.mock("idb-keyval", () => ({
+  del: h.del,
+}));
+
+import { clearOfflineCache } from "./clear-offline-cache";
+import { OFFLINE_CACHE_KEY } from "./query-persister";
+
+// jsdom does not provide indexedDB.databases() or Cache Storage, so the browser
+// globals are stubbed per-test. We restore them afterwards.
+const originalIndexedDB = (globalThis as any).indexedDB;
+const originalCaches = (globalThis as any).caches;
+
+beforeEach(() => {
+  h.clear.mockClear();
+  h.del.mockClear();
+});
+
+afterEach(() => {
+  (globalThis as any).indexedDB = originalIndexedDB;
+  (globalThis as any).caches = originalCaches;
+  vi.restoreAllMocks();
+});
+
+describe("clearOfflineCache", () => {
+  it("resolves without throwing when the browser globals are absent", async () => {
+    (globalThis as any).indexedDB = undefined;
+    delete (globalThis as any).caches;
+
+    await expect(clearOfflineCache()).resolves.toBeUndefined();
+
+    // The two store-agnostic steps still run.
+    expect(h.clear).toHaveBeenCalledTimes(1);
+    expect(h.del).toHaveBeenCalledWith(OFFLINE_CACHE_KEY);
+  });
+
+  it("deletes only `page.*` IndexedDB databases and only `api-get-cache` caches", async () => {
+    const deleteDatabase = vi.fn((_name: string) => {
+      const request: any = {};
+      // Resolve the deletion on the next microtask, like a real IDBRequest.
+      queueMicrotask(() => request.onsuccess && request.onsuccess());
+      return request;
+    });
+    (globalThis as any).indexedDB = {
+      databases: vi
+        .fn()
+        .mockResolvedValue([
+          { name: "page.aaa" },
+          { name: "page.bbb" },
+          { name: "keyval-store" },
+          { name: undefined },
+        ]),
+      deleteDatabase,
+    };
+
+    const cacheDelete = vi.fn().mockResolvedValue(true);
+    (globalThis as any).caches = {
+      keys: vi
+        .fn()
+        .mockResolvedValue([
+          "workbox-runtime-https://app/api-get-cache",
+          "other-cache",
+        ]),
+      delete: cacheDelete,
+    };
+
+    await expect(clearOfflineCache()).resolves.toBeUndefined();
+
+    // Only the two page.* databases are deleted.
+    expect(deleteDatabase).toHaveBeenCalledTimes(2);
+    expect(deleteDatabase).toHaveBeenCalledWith("page.aaa");
+    expect(deleteDatabase).toHaveBeenCalledWith("page.bbb");
+
+    // Only the api-get-cache entry is deleted.
+    expect(cacheDelete).toHaveBeenCalledTimes(1);
+    expect(cacheDelete).toHaveBeenCalledWith(
+      "workbox-runtime-https://app/api-get-cache",
+    );
+  });
+
+  it("never throws even if a step rejects (best-effort)", async () => {
+    h.del.mockRejectedValueOnce(new Error("idb boom"));
+    (globalThis as any).indexedDB = {
+      databases: vi.fn().mockRejectedValue(new Error("databases boom")),
+      deleteDatabase: vi.fn(),
+    };
+    (globalThis as any).caches = {
+      keys: vi.fn().mockRejectedValue(new Error("caches boom")),
+      delete: vi.fn(),
+    };
+
+    await expect(clearOfflineCache()).resolves.toBeUndefined();
+    expect(h.clear).toHaveBeenCalledTimes(1);
+  });
+});

apps/client/src/features/offline/clear-offline-cache.ts

@@ -0,0 +1,112 @@
+import { del } from "idb-keyval";
+
+import { queryClient } from "@/main.tsx";
+import {
+  OFFLINE_CACHE_KEY,
+  freezeOfflinePersistence,
+  unfreezeOfflinePersistence,
+} from "./query-persister";
+import { PAGE_YDOC_NAME_PREFIX } from "@/features/editor/page-ydoc-name";
+
+/**
+ * Best-effort purge of all of the current user's offline data from the browser.
+ *
+ * On logout the previous user's private data would otherwise linger locally and
+ * be readable by the next person on the device. This clears the three offline
+ * stores the app writes:
+ *   1. the in-memory + IndexedDB-persisted TanStack Query cache (idb-keyval key
+ *      `OFFLINE_CACHE_KEY`),
+ *   2. the Yjs page documents (IndexedDB databases named `page.<id>` created by
+ *      y-indexeddb in make-offline.ts), and
+ *   3. any legacy service worker `api-get-cache` Cache Storage entry. The
+ *      Workbox runtime no longer creates this cache (the GET /api NetworkFirst
+ *      rule was removed — offline reads come from the persisted RQ cache), so
+ *      this is now a defensive cleanup for caches left by older app versions.
+ *
+ * Fully best-effort: every step is isolated so a single failure neither blocks
+ * the remaining steps nor throws to the caller (logout must never be blocked on
+ * cache cleanup). Callers may ignore the resolved value.
+ *
+ * Limitations:
+ *   - Deleting the Yjs page databases relies on `indexedDB.databases()`, which
+ *     is unavailable in some browsers (notably Firefox). There we skip silently;
+ *     those `page.<id>` databases are then left in place.
+ *   - Cache Storage clearing only runs where `caches` exists (secure contexts /
+ *     service-worker-capable browsers).
+ */
+export async function clearOfflineCache(): Promise<void> {
+  // Freeze the throttled persister BEFORE touching the cache so the
+  // queryClient.clear() below cannot trigger a late re-write of the (still
+  // nearly-full) dehydrated snapshot after we del() the key — which would
+  // otherwise resurrect the previous user's persisted data in IndexedDB.
+  // Re-enabled in `finally` so the next (sign-in) session persists normally.
+  freezeOfflinePersistence();
+
+  try {
+    // 1a. Drop the in-memory query cache immediately.
+    try {
+      queryClient.clear();
+    } catch {
+      // best-effort: ignore in-memory cache reset failures
+    }
+
+    // 1b. Delete the persisted RQ cache from IndexedDB.
+    try {
+      await del(OFFLINE_CACHE_KEY);
+    } catch {
+      // best-effort: ignore persisted-cache deletion failures
+    }
+
+  // 2. Delete the Yjs page IndexedDB databases (`page.<id>`).
+  // `indexedDB.databases()` is not implemented everywhere (e.g. Firefox); when
+  // it is missing we cannot enumerate the page databases, so we skip silently.
+  try {
+    if (
+      typeof indexedDB !== "undefined" &&
+      typeof indexedDB.databases === "function"
+    ) {
+      const dbs = await indexedDB.databases();
+      for (const db of dbs) {
+        const name = db?.name;
+        if (typeof name !== "string" || !name.startsWith(PAGE_YDOC_NAME_PREFIX))
+          continue;
+        try {
+          // Fire-and-forget delete; await a thin wrapper so a slow delete does
+          // not race the page teardown, but never reject on it.
+          await new Promise<void>((resolve) => {
+            const request = indexedDB.deleteDatabase(name);
+            request.onsuccess = () => resolve();
+            request.onerror = () => resolve();
+            request.onblocked = () => resolve();
+          });
+        } catch {
+          // best-effort per database
+        }
+      }
+    }
+  } catch {
+    // best-effort: ignore enumeration/deletion failures
+  }
+
+  // 3. Clear any legacy service worker API cache. Current builds no longer
+  // create it, but an older client may have left an "api-get-cache" entry
+  // (Workbox may prefix the name), so match by substring rather than exact name.
+  try {
+    if ("caches" in window) {
+      const keys = await caches.keys();
+      await Promise.all(
+        keys
+          .filter((key) => key.includes("api-get-cache"))
+          .map((key) => caches.delete(key)),
+      );
+    }
+  } catch {
+    // best-effort: ignore Cache Storage failures
+  }
+  } finally {
+    // Re-enable persistence for the next session (sign-in continues running in
+    // the same tab; logout reloads via window.location.replace, so this is a
+    // harmless no-op there).
+    unfreezeOfflinePersistence();
+  }
+}

apps/client/src/features/offline/make-offline.test.ts

@@ -0,0 +1,475 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+
+// vi.mock factories are hoisted above imports, so any spy they reference must be
+// declared with vi.hoisted (which is hoisted as well). These shared spies are
+// inspected by the assertions below.
+const h = vi.hoisted(() => ({
+  ydocDestroy: vi.fn(),
+  idbDestroy: vi.fn(),
+  providerOn: vi.fn(),
+  providerOff: vi.fn(),
+  providerDestroy: vi.fn(),
+}));
+
+// The module under test imports the app entry at load time — it must be mocked.
+vi.mock("@/main.tsx", () => ({
+  queryClient: { setQueryData: vi.fn(), prefetchQuery: vi.fn() },
+}));
+vi.mock("@/features/page/services/page-service", () => ({
+  getPageById: vi.fn(),
+  getPageBreadcrumbs: vi.fn(),
+  getSidebarPages: vi.fn(),
+  getAllSidebarPages: vi.fn(),
+}));
+vi.mock("@/features/space/services/space-service.ts", () => ({
+  getSpaceById: vi.fn(),
+}));
+vi.mock("@/features/comment/services/comment-service", () => ({
+  getPageComments: vi.fn(),
+}));
+
+// Use the `function` form (not an arrow) so Vitest binds the constructor return
+// value when the module under test calls `new Y.Doc()` etc.
+vi.mock("yjs", () => ({
+  Doc: vi.fn(function () {
+    return { destroy: h.ydocDestroy };
+  }),
+}));
+vi.mock("y-indexeddb", () => ({
+  IndexeddbPersistence: vi.fn(function () {
+    return { destroy: h.idbDestroy };
+  }),
+}));
+vi.mock("@hocuspocus/provider", () => ({
+  HocuspocusProvider: vi.fn(function () {
+    return { on: h.providerOn, off: h.providerOff, destroy: h.providerDestroy };
+  }),
+}));
+
+import {
+  warmInfiniteAll,
+  warmPageYdoc,
+  makePageAvailableOffline,
+} from "./make-offline";
+import { queryClient } from "@/main.tsx";
+import {
+  getPageById,
+  getPageBreadcrumbs,
+  getSidebarPages,
+} from "@/features/page/services/page-service";
+import { getPageComments } from "@/features/comment/services/comment-service";
+
+const setQueryData = (queryClient as any).setQueryData as ReturnType<
+  typeof vi.fn
+>;
+const prefetchQuery = (queryClient as any).prefetchQuery as ReturnType<
+  typeof vi.fn
+>;
+
+beforeEach(() => {
+  // Clear call history WITHOUT wiping the mock implementations the vi.mock
+  // factories installed (vi.clearAllMocks would drop the constructor return
+  // objects and break the provider/idb/yjs spies).
+  setQueryData.mockClear();
+  prefetchQuery.mockReset();
+  prefetchQuery.mockResolvedValue(undefined);
+  (getPageById as ReturnType<typeof vi.fn>).mockReset();
+  (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockReset();
+  (getSidebarPages as ReturnType<typeof vi.fn>).mockReset();
+  (getPageComments as ReturnType<typeof vi.fn>).mockReset();
+  h.ydocDestroy.mockClear();
+  h.idbDestroy.mockClear();
+  h.providerOn.mockClear();
+  h.providerOff.mockClear();
+  h.providerDestroy.mockClear();
+});
+
+describe("warmInfiniteAll", () => {
+  it("warms a single page and writes the InfiniteData cache shape", async () => {
+    const res = { items: [{ id: 1 }], meta: { nextCursor: null } };
+    const fetchPage = vi.fn().mockResolvedValue(res);
+
+    await warmInfiniteAll(["comments", "p1"], fetchPage);
+
+    expect(fetchPage).toHaveBeenCalledTimes(1);
+    expect(fetchPage).toHaveBeenCalledWith(undefined);
+    expect(setQueryData).toHaveBeenCalledTimes(1);
+    expect(setQueryData).toHaveBeenCalledWith(["comments", "p1"], {
+      pages: [res],
+      pageParams: [undefined],
+    });
+  });
+
+  it("walks the cursor chain across multiple pages", async () => {
+    const r0 = { items: [], meta: { nextCursor: "c1" } };
+    const r1 = { items: [], meta: { nextCursor: "c2" } };
+    const r2 = { items: [], meta: { nextCursor: null } };
+    const fetchPage = vi
+      .fn()
+      .mockResolvedValueOnce(r0)
+      .mockResolvedValueOnce(r1)
+      .mockResolvedValueOnce(r2);
+
+    await warmInfiniteAll(["comments", "p1"], fetchPage);
+
+    expect(fetchPage).toHaveBeenCalledTimes(3);
+    expect(fetchPage.mock.calls.map((c) => c[0])).toEqual([
+      undefined,
+      "c1",
+      "c2",
+    ]);
+    const payload = setQueryData.mock.calls[0][1];
+    expect(payload.pages).toEqual([r0, r1, r2]);
+    expect(payload.pageParams).toEqual([undefined, "c1", "c2"]);
+  });
+
+  it("caps pagination at maxPages and reports the truncation (returns false)", async () => {
+    // Always returns a non-null cursor — the cap is the only thing that stops it.
+    const fetchPage = vi
+      .fn()
+      .mockResolvedValue({ items: [], meta: { nextCursor: "more" } });
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+
+    // Hitting maxPages with a cursor still pending is a truncated warm: the
+    // (partial) cache is still written, but the result is reported as false.
+    await expect(
+      warmInfiniteAll(["comments", "p1"], fetchPage, 2),
+    ).resolves.toBe(false);
+
+    expect(fetchPage).toHaveBeenCalledTimes(2);
+    const payload = setQueryData.mock.calls[0][1];
+    expect(payload.pages).toHaveLength(2);
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  it("returns true on success", async () => {
+    const fetchPage = vi
+      .fn()
+      .mockResolvedValue({ items: [], meta: { nextCursor: null } });
+
+    await expect(
+      warmInfiniteAll(["comments", "p1"], fetchPage),
+    ).resolves.toBe(true);
+  });
+
+  it("reports errors (returns false) and never writes the cache on failure", async () => {
+    const fetchPage = vi.fn().mockRejectedValue(new Error("network"));
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+
+    await expect(
+      warmInfiniteAll(["comments", "p1"], fetchPage),
+    ).resolves.toBe(false);
+    expect(setQueryData).not.toHaveBeenCalled();
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+});
+
+describe("makePageAvailableOffline", () => {
+  const okPage = {
+    id: "uuid-1",
+    slugId: "slug-1",
+    space: { slug: "space-slug" },
+  };
+
+  it("returns ok:true with no failures when every step succeeds", async () => {
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    expect(result).toEqual({ ok: true, failed: [] });
+  });
+
+  it("returns ok:false with the failed step label when a warm step fails", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    // Comments warm fails -> labeled "comments".
+    (getPageComments as ReturnType<typeof vi.fn>).mockRejectedValue(
+      new Error("network"),
+    );
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.failed).toContain("comments");
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  // Helper: the page-ids passed to the sidebar-children warm (its query key is
+  // ["sidebar-pages", { pageId, spaceId }]) — i.e. which nodes were prefetched.
+  const warmedSidebarIds = () =>
+    prefetchQuery.mock.calls
+      .map((c) => c[0])
+      .filter((opts: any) => opts?.queryKey?.[0] === "sidebar-pages")
+      .map((opts: any) => opts.queryKey[1]?.pageId);
+
+  it("warms the page + every ancestor's children once and skips the self-ancestor guard", async () => {
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    // Breadcrumbs include two real ancestors, the page's OWN id (must be skipped
+    // by the ancestorId === pageId guard so it is not warmed twice), and a
+    // malformed entry with no id (also skipped).
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([
+      { id: "anc-1" },
+      { id: "uuid-1" }, // === pageId -> guard
+      { id: "anc-2" },
+      {}, // no id -> skipped
+    ]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    const ids = warmedSidebarIds();
+    // The page's own children (warmSidebarChildren(pageId)) plus each real
+    // ancestor — exactly once each. The self-ancestor (uuid-1 in breadcrumbs) is
+    // NOT a second warm: uuid-1 appears once (from the page's own children call).
+    expect(ids).toEqual(["uuid-1", "anc-1", "anc-2"]);
+    expect(ids.filter((id: string) => id === "uuid-1")).toHaveLength(1);
+    expect(result).toEqual({ ok: true, failed: [] });
+  });
+
+  it("dedupes repeated tree failures into a single 'tree' label", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([
+      { id: "anc-1" },
+      { id: "anc-2" },
+    ]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    // Fail ONLY the sidebar-children prefetches (page-own + both ancestors = 3
+    // failures); the currentUser/space prefetches still resolve.
+    prefetchQuery.mockImplementation(async (opts: any) => {
+      if (opts?.queryKey?.[0] === "sidebar-pages") throw new Error("network");
+      return undefined;
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    // Three node warms failed but the contract collapses them to one "tree".
+    expect(result.ok).toBe(false);
+    expect(result.failed).toEqual(["tree"]);
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  it("records 'breadcrumbs' (not 'tree') when the breadcrumbs lookup rejects", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    // Ancestor discovery fails -> the ancestor-walk is recorded as "breadcrumbs".
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockRejectedValue(
+      new Error("network"),
+    );
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    // The page's own children still warmed fine (prefetch resolves), so the only
+    // failure is the breadcrumbs lookup.
+    expect(result.ok).toBe(false);
+    expect(result.failed).toEqual(["breadcrumbs"]);
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  it("records 'page' when the central document fetch (getPageById) rejects", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    // The central page document fetch fails (the most realistic failure).
+    (getPageById as ReturnType<typeof vi.fn>).mockRejectedValue(
+      new Error("network"),
+    );
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    // With no page document, the space step is skipped (no slug), so the only
+    // failure label is "page".
+    expect(result.ok).toBe(false);
+    expect(result.failed).toContain("page");
+    expect(result.failed).not.toContain("space");
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  it("records 'space' when ONLY the space prefetch rejects", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    // Fail ONLY the space prefetch (queryKey ["space", slug]); the currentUser
+    // and sidebar-children prefetches still resolve.
+    prefetchQuery.mockImplementation(async (opts: any) => {
+      if (opts?.queryKey?.[0] === "space") throw new Error("network");
+      return undefined;
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.failed).toContain("space");
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  it("records 'currentUser' when ONLY the currentUser prefetch rejects", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    // Fail ONLY the currentUser prefetch (queryKey ["currentUser"]); the space
+    // and sidebar-children prefetches still resolve.
+    prefetchQuery.mockImplementation(async (opts: any) => {
+      if (opts?.queryKey?.[0] === "currentUser") throw new Error("network");
+      return undefined;
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.failed).toContain("currentUser");
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+});
+
+describe("warmPageYdoc", () => {
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("resolves on synced, detaches the listener once, and tears everything down (settle-once)", async () => {
+    const promise = warmPageYdoc("p1", "ws://x");
+
+    // Grab the synced handler the provider registered.
+    expect(h.providerOn).toHaveBeenCalledWith("synced", expect.any(Function));
+    const handler = h.providerOn.mock.calls.find(
+      (c) => c[0] === "synced",
+    )![1] as () => void;
+
+    handler();
+    // Returns true because the real "synced" event fired.
+    await expect(promise).resolves.toBe(true);
+
+    // Listener detached and everything cleaned up.
+    expect(h.providerOff).toHaveBeenCalledWith("synced", expect.any(Function));
+    expect(h.providerDestroy).toHaveBeenCalledTimes(1);
+    expect(h.idbDestroy).toHaveBeenCalledTimes(1);
+    expect(h.ydocDestroy).toHaveBeenCalledTimes(1);
+
+    // Firing the handler again must NOT re-run cleanup (settled guard).
+    handler();
+    expect(h.providerDestroy).toHaveBeenCalledTimes(1);
+    expect(h.idbDestroy).toHaveBeenCalledTimes(1);
+    expect(h.ydocDestroy).toHaveBeenCalledTimes(1);
+  });
+
+  it("resolves false and cleans up after the timeout when synced never fires", async () => {
+    vi.useFakeTimers();
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    const promise = warmPageYdoc("p1", "ws://x");
+
+    // Do not fire "synced"; let the 8s safety timeout settle it.
+    await vi.advanceTimersByTimeAsync(8000);
+    // Returns false (the doc never synced) and logs the timeout with the pageId.
+    await expect(promise).resolves.toBe(false);
+    expect(errorSpy).toHaveBeenCalledWith(
+      "warmPageYdoc: timed out before sync",
+      { pageId: "p1" },
+    );
+
+    expect(h.providerDestroy).toHaveBeenCalledTimes(1);
+    expect(h.idbDestroy).toHaveBeenCalledTimes(1);
+    expect(h.ydocDestroy).toHaveBeenCalledTimes(1);
+
+    errorSpy.mockRestore();
+  });
+});

apps/client/src/features/offline/make-offline.ts

@@ -0,0 +1,337 @@
+import * as Y from "yjs";
+import { IndexeddbPersistence } from "y-indexeddb";
+import { HocuspocusProvider } from "@hocuspocus/provider";
+
+import { queryClient } from "@/main.tsx";
+import {
+  getPageById,
+  getPageBreadcrumbs,
+  getSidebarPages,
+} from "@/features/page/services/page-service";
+import {
+  pageKeys,
+  sidebarPagesQueryOptions,
+} from "@/features/page/queries/page-query";
+import { spaceByIdQueryOptions } from "@/features/space/queries/space-query";
+import { RQ_KEY } from "@/features/comment/queries/comment-query";
+import { getPageComments } from "@/features/comment/services/comment-service";
+import { getMyInfo } from "@/features/user/services/user-service";
+import { userKeys } from "@/features/user/hooks/use-current-user";
+import { IPage } from "@/features/page/types/page.types";
+import { IPagination } from "@/lib/types.ts";
+import { pageYdocName } from "@/features/editor/page-ydoc-name";
+
+/**
+ * Fully paginate an infinite query and write the @tanstack InfiniteData cache
+ * shape ({ pages, pageParams }) that the matching useInfiniteQuery hook reads.
+ *
+ * The default prefetchInfiniteQuery only warms the FIRST page, which leaves
+ * hooks that treat hasNextPage as still-loading (e.g. the comments panel)
+ * spinning forever offline, and silently truncates large lists. This walks the
+ * cursor chain until it runs out (or hits maxPages) so the whole list is cached.
+ *
+ * Best-effort: a failure does not throw (a partial/failed warm is still useful),
+ * but it is reported — the error is logged with context and `false` is returned
+ * so the caller can record the failed step instead of silently succeeding.
+ *
+ * Returns true ONLY if the cursor chain was fully exhausted and written. If the
+ * walk stops because it hit `maxPages` while a `nextCursor` is still pending,
+ * the cached list is truncated AND its last page keeps a nextCursor that cannot
+ * be re-fetched offline (hooks that gate on hasNextPage would spin forever), so
+ * that case is logged and returns false too — the caller records it as a failed
+ * warm instead of a silent truncated success. The (partial) cache is still
+ * written so what we did fetch is usable.
+ *
+ * Exported for unit testing of the cursor-walk / cache-write behavior.
+ */
+export async function warmInfiniteAll<T>(
+  queryKey: readonly unknown[],
+  fetchPage: (cursor: string | undefined) => Promise<IPagination<T>>,
+  maxPages = 50,
+): Promise<boolean> {
+  try {
+    const pages: IPagination<T>[] = [];
+    const pageParams: (string | undefined)[] = [];
+    let cursor: string | undefined = undefined;
+    let exhausted = false;
+
+    for (let i = 0; i < maxPages; i++) {
+      const res = await fetchPage(cursor);
+      pages.push(res);
+      pageParams.push(cursor);
+      cursor = res?.meta?.nextCursor ?? undefined;
+      if (!cursor) {
+        exhausted = true;
+        break;
+      }
+    }
+
+    queryClient.setQueryData(queryKey, { pages, pageParams });
+
+    if (!exhausted) {
+      // Stopped at maxPages with a cursor still pending: the list is truncated
+      // and the last cached page's nextCursor is un-fetchable offline. Report it
+      // as a failed warm rather than a silent truncated success.
+      console.error("warmInfiniteAll truncated at maxPages", {
+        queryKey,
+        maxPages,
+      });
+      return false;
+    }
+    return true;
+  } catch (error) {
+    console.error("warmInfiniteAll failed", { queryKey, error });
+    return false;
+  }
+}
+
+export interface MakePageAvailableOfflineParams {
+  pageId: string;
+  spaceId?: string;
+}
+
+/**
+ * Outcome of {@link makePageAvailableOffline}. `ok` is true only when every warm
+ * step succeeded; `failed` lists the labels of the steps that failed (a subset
+ * of: "currentUser", "page", "space", "tree", "breadcrumbs", "comments").
+ */
+export interface MakePageAvailableOfflineResult {
+  ok: boolean;
+  failed: string[];
+}
+
+/**
+ * Best-effort prefetch of a page's read queries so they get persisted to
+ * IndexedDB and become readable offline.
+ *
+ * Each step is isolated and this function does NOT throw — a partial warm is
+ * still useful. Instead of silently succeeding, every failed step is logged
+ * with a label and recorded in the returned result: `{ ok, failed }` where
+ * `ok` is true only if no step failed and `failed` lists the failed step
+ * labels. Only meaningful while online (the underlying requests must succeed).
+ */
+export async function makePageAvailableOffline({
+  pageId,
+  spaceId,
+}: MakePageAvailableOfflineParams): Promise<MakePageAvailableOfflineResult> {
+  const failed: string[] = [];
+
+  // Warm the current user (['currentUser']) so the auth-gated <Layout> can
+  // hydrate offline. UserProvider blanks the whole app while useCurrentUser has
+  // no data, and the offline POST /api/users/me fails as a network error, so
+  // without a persisted user a pinned page still white-screens after relaunch
+  // (#238). Persisted via OFFLINE_PERSIST_ROOTS; warmed here so the persisted
+  // cache actually has an entry to restore.
+  try {
+    await queryClient.prefetchQuery({
+      queryKey: userKeys.currentUser(),
+      queryFn: () => getMyInfo(),
+    });
+  } catch (error) {
+    console.error("makePageAvailableOffline: currentUser step failed", {
+      pageId,
+      error,
+    });
+    failed.push("currentUser");
+  }
+
+  // Fetch the page document ONCE and write it under BOTH cache keys, exactly
+  // like usePageQuery's onData effect. Every page consumer reads
+  // pageKeys.detail(slugId) (usePageQuery keys on the slugId for routed reads),
+  // so warming only the uuid key would leave the offline page blank.
+  let page: IPage | undefined;
+  try {
+    page = await getPageById({ pageId });
+    queryClient.setQueryData(pageKeys.detail(page.slugId), page);
+    queryClient.setQueryData(pageKeys.detail(page.id), page);
+  } catch (error) {
+    console.error("makePageAvailableOffline: page step failed", {
+      pageId,
+      error,
+    });
+    failed.push("page");
+  }
+
+  // Warm the space — page.tsx renders nothing until the space query resolves
+  // (useGetSpaceBySlugQuery). Awaited (not the fire-and-forget prefetchSpace) so
+  // the space is actually persisted before the caller fires its toast. Shares
+  // spaceByIdQueryOptions so the key/fn cannot drift from the hook.
+  try {
+    const spaceSlug = page?.space?.slug;
+    if (spaceSlug) {
+      await queryClient.prefetchQuery(spaceByIdQueryOptions(spaceSlug));
+    }
+  } catch (error) {
+    console.error("makePageAvailableOffline: space step failed", {
+      pageId,
+      error,
+    });
+    failed.push("space");
+  }
+
+  // Warm the sidebar tree root so the WHOLE root level renders offline (matches
+  // useGetRootSidebarPagesQuery's pageKeys.rootSidebar(spaceId) infinite cache).
+  // Fully paginated so large root levels are not truncated at 100.
+  if (spaceId) {
+    const ok = await warmInfiniteAll(pageKeys.rootSidebar(spaceId), (cursor) =>
+      getSidebarPages({ spaceId, cursor, limit: 100 }),
+    );
+    if (!ok) failed.push("tree");
+  }
+
+  // Warm the children of the page and of every ancestor so the path to this
+  // page is expandable offline. We MIRROR fetchAllAncestorChildren exactly via
+  // sidebarPagesQueryOptions — same pageKeys.sidebar({ pageId, spaceId }) key,
+  // same getAllSidebarPages fn (which aggregates ALL children pages, so nothing
+  // is truncated at 100), same 30min staleTime — otherwise the warmed cache
+  // would never be read by the offline tree.
+  const warmSidebarChildren = async (id: string): Promise<boolean> => {
+    try {
+      // Keep EXACTLY { pageId, spaceId } so the key hashes identically to
+      // fetchAllAncestorChildren's (no parentPageId, no extra fields).
+      const params = { pageId: id, spaceId };
+      await queryClient.prefetchQuery(sidebarPagesQueryOptions(params));
+      return true;
+    } catch (error) {
+      console.error("makePageAvailableOffline: tree node step failed", {
+        pageId: id,
+        error,
+      });
+      return false;
+    }
+  };
+
+  // The page's own children.
+  if (!(await warmSidebarChildren(pageId))) failed.push("tree");
+
+  // Each ancestor's children. Use the breadcrumbs endpoint ONLY to discover the
+  // ancestor ids — we intentionally do NOT cache the breadcrumbs themselves
+  // (the UI derives the path from the tree).
+  try {
+    const ancestors = (await getPageBreadcrumbs(pageId)) as
+      | Array<{ id?: string }>
+      | undefined;
+    for (const ancestor of ancestors ?? []) {
+      const ancestorId = ancestor?.id;
+      if (!ancestorId || ancestorId === pageId) continue;
+      if (!(await warmSidebarChildren(ancestorId))) failed.push("tree");
+    }
+  } catch (error) {
+    console.error("makePageAvailableOffline: breadcrumbs step failed", {
+      pageId,
+      error,
+    });
+    failed.push("breadcrumbs");
+  }
+
+  // Comments (matches useCommentsQuery's RQ_KEY(pageId) infinite cache).
+  // useCommentsQuery reports isLoading while hasNextPage is true, so warming
+  // only the first page leaves the offline comments panel spinning forever on
+  // pages with >100 comments. Fully paginate so the last cached page has no
+  // nextCursor and the panel settles offline.
+  const commentsOk = await warmInfiniteAll(RQ_KEY(pageId), (cursor) =>
+    getPageComments({ pageId, cursor, limit: 100 }),
+  );
+  if (!commentsOk) failed.push("comments");
+
+  // Dedupe — the tree label can be recorded once per failed node/ancestor.
+  const uniqueFailed = [...new Set(failed)];
+  return { ok: uniqueFailed.length === 0, failed: uniqueFailed };
+}
+
+/**
+ * Best-effort warm-up of the page's Yjs document into IndexedDB so the editor
+ * can open offline.
+ *
+ * Opens a local IndexeddbPersistence plus a transient HocuspocusProvider to
+ * pull the server state into IndexedDB, then tears both down once synced (or
+ * after a timeout). Entirely wrapped in try/catch — NEVER throws.
+ *
+ * Returns true ONLY when the provider's real "synced" event fired — i.e. the
+ * server state actually landed in IndexedDB. The timeout and failure paths
+ * return false (and log with the pageId) so the caller does not report a page
+ * as offline-available when its editor body never warmed. For a wiki the editor
+ * body IS the page, so a silent timeout here is a real misreport.
+ *
+ * Only meaningful when online at warm time; offline it is a no-op that resolves.
+ */
+export async function warmPageYdoc(
+  pageId: string,
+  collabUrl: string,
+  token?: string,
+): Promise<boolean> {
+  let ydoc: Y.Doc | null = null;
+  let local: IndexeddbPersistence | null = null;
+  let remote: HocuspocusProvider | null = null;
+  // Flipped to true ONLY inside the real "synced" handler; the timeout/failure
+  // paths leave it false. Returned so the caller can record a failed editor warm.
+  let didSync = false;
+
+  try {
+    const documentName = pageYdocName(pageId);
+    ydoc = new Y.Doc();
+    local = new IndexeddbPersistence(documentName, ydoc);
+    remote = new HocuspocusProvider({
+      url: collabUrl,
+      name: documentName,
+      document: ydoc,
+      token,
+    });
+
+    const provider = remote;
+
+    await new Promise<void>((resolve) => {
+      let settled = false;
+      let timeoutId: ReturnType<typeof setTimeout> | undefined;
+      // `synced` is true only when called from the real "synced" handler; the
+      // timeout path passes false so didSync stays false on a give-up.
+      const finish = (synced: boolean) => {
+        if (settled) return;
+        settled = true;
+        didSync = synced;
+        // Clear the pending timeout and detach the listener so neither leaks
+        // after we resolve.
+        if (timeoutId !== undefined) clearTimeout(timeoutId);
+        try {
+          provider.off("synced", onSynced);
+        } catch {
+          // best-effort
+        }
+        if (!synced) {
+          // Gave up before the server synced: the page body never landed in
+          // IndexedDB. Log with the pageId (parity with the other warm steps)
+          // so the caller can report the editor step as failed.
+          console.error("warmPageYdoc: timed out before sync", { pageId });
+        }
+        resolve();
+      };
+
+      const onSynced = () => finish(true);
+
+      // Resolve once the server state has synced into the local doc...
+      provider.on("synced", onSynced);
+      // ...or give up after a short timeout so we never hang.
+      timeoutId = setTimeout(() => finish(false), 8000);
+    });
+  } catch (error) {
+    console.error("warmPageYdoc: warm failed", { pageId, error });
+  } finally {
+    try {
+      remote?.destroy();
+    } catch {
+      // best-effort
+    }
+    try {
+      local?.destroy();
+    } catch {
+      // best-effort
+    }
+    try {
+      ydoc?.destroy();
+    } catch {
+      // best-effort
+    }
+  }
+
+  return didSync;
+}

apps/client/src/features/offline/offline-fallback.tsx

@@ -0,0 +1,45 @@
+import { Button, Container, Group, Stack, Text, Title } from "@mantine/core";
+import { Helmet } from "react-helmet-async";
+import { useTranslation } from "react-i18next";
+import { getAppName } from "@/lib/config";
+
+/**
+ * Shown when the authenticated app shell cannot hydrate because the current
+ * user is unavailable AND there is no cached user to fall back on (e.g. an
+ * offline cold boot of a page that was never warmed for offline).
+ *
+ * Previously UserProvider returned a bare `<></>` in this situation, which
+ * white-screened the whole app on any offline reload (#237/#238). Rendering an
+ * explicit "you're offline" state with a retry instead gives the user a clear,
+ * non-blank fallback and a way to recover once the network returns.
+ */
+export function OfflineFallback() {
+  const { t } = useTranslation();
+
+  return (
+    <>
+      <Helmet>
+        <title>
+          {t("You're offline")} - {getAppName()}
+        </title>
+      </Helmet>
+      <Container size="sm" py={80}>
+        <Stack align="center" gap="md">
+          <Title order={2} ta="center">
+            {t("You're offline")}
+          </Title>
+          <Text c="dimmed" size="lg" ta="center">
+            {t(
+              "This page hasn't been saved for offline use, so it can't be loaded right now. Reconnect to the internet and try again.",
+            )}
+          </Text>
+          <Group justify="center">
+            <Button onClick={() => window.location.reload()} variant="subtle">
+              {t("Retry")}
+            </Button>
+          </Group>
+        </Stack>
+      </Container>
+    </>
+  );
+}

apps/client/src/features/offline/offline-mutations.test.ts

@@ -0,0 +1,114 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { QueryClient, hydrate, dehydrate } from "@tanstack/react-query";
+
+// Stub the network services so a replayed mutation hits a spy, not the network.
+const h = vi.hoisted(() => ({
+  createPage: vi.fn(),
+  movePage: vi.fn(),
+  createComment: vi.fn(),
+}));
+
+vi.mock("@/features/page/services/page-service", () => ({
+  createPage: h.createPage,
+  movePage: h.movePage,
+}));
+vi.mock("@/features/comment/services/comment-service", () => ({
+  createComment: h.createComment,
+}));
+// page-query pulls in the app entry (queryClient) and a lot of UI deps via its
+// cache helpers; we only need invalidateOnCreatePage to be a no-op here.
+vi.mock("@/features/page/queries/page-query", () => ({
+  invalidateOnCreatePage: vi.fn(),
+}));
+
+import {
+  offlineMutationKeys,
+  registerOfflineMutationDefaults,
+} from "./offline-mutations";
+
+beforeEach(() => {
+  h.createPage.mockReset().mockResolvedValue({ id: "new-page" });
+  h.movePage.mockReset().mockResolvedValue(undefined);
+  h.createComment.mockReset().mockResolvedValue({ id: "new-comment" });
+});
+
+describe("registerOfflineMutationDefaults", () => {
+  it("registers a default mutationFn for every offline mutation key", () => {
+    const qc = new QueryClient();
+    registerOfflineMutationDefaults(qc);
+
+    for (const key of Object.values(offlineMutationKeys)) {
+      const defaults = qc.getMutationDefaults(key);
+      expect(typeof defaults?.mutationFn).toBe("function");
+    }
+  });
+
+  // The headline durability guarantee: a paused mutation dehydrated into
+  // IndexedDB while offline must, after a reload, have a mutationFn so
+  // resumePausedMutations() actually replays the write on reconnect.
+  it("makes a rehydrated paused create replayable by resumePausedMutations", async () => {
+    // 1) Simulate the offline tab: a paused create mutation gets dehydrated.
+    const offlineClient = new QueryClient();
+    const observer = offlineClient.getMutationCache().build(offlineClient, {
+      mutationKey: offlineMutationKeys.createPage,
+    });
+    // Force the dehydrate-worthy paused state (offline = isPaused) with the
+    // payload the user submitted before losing connectivity.
+    observer.state.isPaused = true;
+    observer.state.status = "pending";
+    observer.state.variables = { spaceId: "s1", title: "Offline page" };
+
+    const dehydrated = dehydrate(offlineClient, {
+      shouldDehydrateMutation: () => true,
+    });
+    expect(dehydrated.mutations).toHaveLength(1);
+    // The dehydrated mutation carries NO mutationFn (functions aren't
+    // serializable) — only its key + variables survive the reload.
+    expect((dehydrated.mutations[0] as any).mutationFn).toBeUndefined();
+
+    // 2) Simulate the fresh page after reload: register defaults, then hydrate
+    //    the persisted paused mutation back in.
+    const freshClient = new QueryClient();
+    registerOfflineMutationDefaults(freshClient);
+    hydrate(freshClient, dehydrated);
+
+    expect(freshClient.getMutationCache().getAll()).toHaveLength(1);
+
+    // 3) Reconnect: replay the paused mutations.
+    await freshClient.resumePausedMutations();
+
+    // The default mutationFn ran with the persisted variables — the write is
+    // NOT silently dropped.
+    expect(h.createPage).toHaveBeenCalledTimes(1);
+    expect(h.createPage).toHaveBeenCalledWith({
+      spaceId: "s1",
+      title: "Offline page",
+    });
+  });
+
+  it("makes a rehydrated paused move replayable by resumePausedMutations", async () => {
+    const offlineClient = new QueryClient();
+    const observer = offlineClient.getMutationCache().build(offlineClient, {
+      mutationKey: offlineMutationKeys.movePage,
+    });
+    observer.state.isPaused = true;
+    observer.state.status = "pending";
+    observer.state.variables = { pageId: "p1", parentPageId: null, position: "a" };
+
+    const dehydrated = dehydrate(offlineClient, {
+      shouldDehydrateMutation: () => true,
+    });
+
+    const freshClient = new QueryClient();
+    registerOfflineMutationDefaults(freshClient);
+    hydrate(freshClient, dehydrated);
+    await freshClient.resumePausedMutations();
+
+    expect(h.movePage).toHaveBeenCalledTimes(1);
+    expect(h.movePage).toHaveBeenCalledWith({
+      pageId: "p1",
+      parentPageId: null,
+      position: "a",
+    });
+  });
+});

apps/client/src/features/offline/offline-mutations.ts

@@ -0,0 +1,64 @@
+import type { QueryClient } from "@tanstack/react-query";
+import { createPage, movePage } from "@/features/page/services/page-service";
+import { createComment } from "@/features/comment/services/comment-service";
+import { invalidateOnCreatePage } from "@/features/page/queries/page-query";
+import type {
+  IMovePage,
+  IPage,
+  IPageInput,
+} from "@/features/page/types/page.types";
+import type { IComment } from "@/features/comment/types/comment.types";
+
+/**
+ * Stable mutation keys for the offline-relevant structural mutations.
+ *
+ * When the browser goes offline, React Query PAUSES these mutations and the
+ * PersistQueryClientProvider dehydrates the paused mutation into IndexedDB. On a
+ * reload-while-offline the mutation is restored, but a restored mutation has NO
+ * observer (no component is mounted) — so its replay relies entirely on the
+ * `mutationFn` registered via `setMutationDefaults` for its `mutationKey`.
+ * Without that, `resumePausedMutations()` finds a paused mutation with no
+ * `mutationFn` and silently no-ops, dropping the offline create/move/comment
+ * (#237/#238). Each offline mutation hook tags itself with the matching key so
+ * the rehydrated paused mutation can find its default `mutationFn` and replay.
+ */
+export const offlineMutationKeys = {
+  createPage: ["create-page"] as const,
+  movePage: ["move-page"] as const,
+  createComment: ["create-comment"] as const,
+};
+
+/**
+ * Register default `mutationFn`s (and the minimal success side effects safe to
+ * run without a mounted component) for the offline-relevant mutation keys, so a
+ * paused mutation restored from IndexedDB after an offline reload is replayable
+ * by `resumePausedMutations()` on reconnect.
+ *
+ * Called once when the QueryClient is created (see main.tsx). The hooks still
+ * carry their own inline `mutationFn`/`onSuccess` for the live in-session path;
+ * these defaults only take over for a rehydrated paused mutation that lost its
+ * observer across the reload.
+ */
+export function registerOfflineMutationDefaults(queryClient: QueryClient): void {
+  queryClient.setMutationDefaults(offlineMutationKeys.createPage, {
+    mutationFn: (data: Partial<IPageInput>) => createPage(data),
+    // Re-converge the sidebar tree / recent-changes from the authoritative
+    // create response. Pure cache writes — safe with no component mounted.
+    onSuccess: (data: IPage) => {
+      invalidateOnCreatePage(data);
+    },
+  });
+
+  queryClient.setMutationDefaults(offlineMutationKeys.movePage, {
+    // Replay the server-side move. The tree re-converges from the next online
+    // sidebar fetch / websocket `moveTreeNode` echo, so no cache write is
+    // needed here (the optimistic tree state was local-only anyway).
+    mutationFn: (data: IMovePage) => movePage(data),
+  });
+
+  queryClient.setMutationDefaults(offlineMutationKeys.createComment, {
+    // Replay the server-side comment create. The comments list refetches on the
+    // online reload, so the replay only needs to persist the write.
+    mutationFn: (data: Partial<IComment>) => createComment(data),
+  });
+}

apps/client/src/features/offline/offline-resume.test.ts

@@ -0,0 +1,128 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { QueryClient, onlineManager } from "@tanstack/react-query";
+import {
+  persistQueryClientRestore,
+  persistQueryClientSave,
+} from "@tanstack/react-query-persist-client";
+
+// Stub the network services so a replayed mutation hits a spy, not the network.
+const h = vi.hoisted(() => ({
+  createPage: vi.fn(),
+  movePage: vi.fn(),
+  createComment: vi.fn(),
+}));
+
+vi.mock("@/features/page/services/page-service", () => ({
+  createPage: h.createPage,
+  movePage: h.movePage,
+}));
+vi.mock("@/features/comment/services/comment-service", () => ({
+  createComment: h.createComment,
+}));
+vi.mock("@/features/page/queries/page-query", () => ({
+  invalidateOnCreatePage: vi.fn(),
+}));
+
+// In-memory idb-keyval so the REAL queryPersister round-trips through a fake
+// store (the actual persist -> reload -> restore path, not a hand-built blob).
+const store = new Map<string, string>();
+vi.mock("idb-keyval", () => ({
+  get: vi.fn((k: string) => Promise.resolve(store.get(k) ?? undefined)),
+  set: vi.fn((k: string, v: string) => {
+    store.set(k, v);
+    return Promise.resolve();
+  }),
+  del: vi.fn((k: string) => {
+    store.delete(k);
+    return Promise.resolve();
+  }),
+}));
+
+import { queryPersister } from "./query-persister";
+import {
+  offlineMutationKeys,
+  registerOfflineMutationDefaults,
+} from "./offline-mutations";
+
+const BUSTER = "test-buster";
+
+beforeEach(() => {
+  store.clear();
+  h.createPage.mockReset().mockResolvedValue({ id: "new-page" });
+  h.movePage.mockReset().mockResolvedValue(undefined);
+  h.createComment.mockReset().mockResolvedValue({ id: "new-comment" });
+});
+
+afterEach(() => {
+  // onlineManager is a global singleton; leave it in the default online state.
+  onlineManager.setOnline(true);
+});
+
+describe("offline paused-mutation resume across a reload", () => {
+  // This is the #120 silent-data-loss reproduction: a paused mutation persisted
+  // to IndexedDB while offline, then the tab RELOADS while still offline, must
+  // resume on reconnect. It exercises the real persister round-trip plus the two
+  // boot-time fixes the app wiring relies on:
+  //   (a) onlineManager seeded to the real offline state so the later reconnect
+  //       is a true offline->online transition that auto-resumes, and
+  //   (b) resumePausedMutations() called after the persister restores (what the
+  //       PersistQueryClientProvider onSuccess does), with mutation defaults
+  //       registered BEFORE the resume so the rehydrated mutation has a fn.
+  it("replays a rehydrated paused create on reconnect (mutationFn fires)", async () => {
+    // --- Tab 1, OFFLINE: user creates a page; it pauses and gets persisted. ---
+    onlineManager.setOnline(false); // (a) boot seeded offline
+
+    const client1 = new QueryClient();
+    registerOfflineMutationDefaults(client1);
+    const observer = client1.getMutationCache().build(client1, {
+      mutationKey: offlineMutationKeys.createPage,
+    });
+    observer.state.isPaused = true;
+    observer.state.status = "pending";
+    observer.state.variables = { spaceId: "s1", title: "Offline page" };
+
+    await persistQueryClientSave({
+      // Cast: persist-client-core and react-query may resolve to different
+      // @tanstack/query-core copies whose QueryClient brands are nominally
+      // incompatible (see query-persister.ts). Structurally identical at runtime.
+      queryClient: client1 as any,
+      persister: queryPersister,
+      buster: BUSTER,
+      dehydrateOptions: { shouldDehydrateMutation: () => true },
+    });
+    // The paused mutation is now in the persisted store.
+    expect(store.size).toBe(1);
+
+    // --- RELOAD while still offline: fresh client restores from the SAME
+    //     persister. Defaults are registered BEFORE restore/resume. ---
+    const client2 = new QueryClient();
+    registerOfflineMutationDefaults(client2);
+    client2.mount(); // subscribes to onlineManager (auto-resume on reconnect)
+
+    await persistQueryClientRestore({
+      queryClient: client2 as any,
+      persister: queryPersister,
+      buster: BUSTER,
+    });
+    expect(client2.getMutationCache().getAll()).toHaveLength(1);
+
+    // (b) onSuccess wiring resumes after restore — but we are still OFFLINE, so
+    // the mutation must stay paused and NOT fire yet.
+    await client2.resumePausedMutations();
+    expect(h.createPage).not.toHaveBeenCalled();
+
+    // --- RECONNECT: the offline->online transition auto-resumes the paused
+    //     mutation and its registered default mutationFn finally fires. ---
+    onlineManager.setOnline(true);
+
+    await vi.waitFor(() => {
+      expect(h.createPage).toHaveBeenCalledTimes(1);
+    });
+    expect(h.createPage).toHaveBeenCalledWith({
+      spaceId: "s1",
+      title: "Offline page",
+    });
+
+    client2.unmount();
+  });
+});

apps/client/src/features/offline/persist-roots.guard.test.ts

@@ -0,0 +1,48 @@
+import { describe, it, expect } from "vitest";
+
+// The query modules transitively import the app entry (@/main.tsx) for the
+// shared queryClient; mock it so importing the key factories has no side effects.
+import { vi } from "vitest";
+vi.mock("@/main.tsx", () => ({
+  queryClient: { setQueryData: vi.fn(), getQueryData: vi.fn() },
+}));
+
+import { OFFLINE_PERSIST_ROOTS } from "./query-persister";
+import { pageKeys } from "@/features/page/queries/page-query";
+import { spaceKeys } from "@/features/space/queries/space-query";
+import { RQ_KEY } from "@/features/comment/queries/comment-query";
+import { userKeys } from "@/features/user/hooks/use-current-user";
+
+/**
+ * Architecture guard (#13): every string persisted via OFFLINE_PERSIST_ROOTS
+ * must be the ROOT (queryKey[0]) of some exported query-key factory. If a
+ * factory's root is renamed without updating the persist registry — or vice
+ * versa — offline persist/warm silently breaks (persisted keys never match the
+ * live queries). This turns that silent regression into a red build.
+ *
+ * Each factory is invoked with throwaway args; only queryKey[0] is inspected.
+ */
+function rootOf(key: readonly unknown[]): string {
+  return String(key[0]);
+}
+
+const FACTORY_ROOTS = new Set<string>([
+  rootOf(pageKeys.detail("x")),
+  rootOf(pageKeys.sidebar({})),
+  rootOf(pageKeys.rootSidebar("x")),
+  rootOf(pageKeys.breadcrumbs("x")),
+  rootOf(pageKeys.recentChanges("x")),
+  rootOf(spaceKeys.detail("x")),
+  rootOf(spaceKeys.list()),
+  rootOf(RQ_KEY("x")),
+  rootOf(userKeys.currentUser()),
+]);
+
+describe("OFFLINE_PERSIST_ROOTS is backed by real query-key factories", () => {
+  it("maps every persisted root to an exported factory root", () => {
+    const unbacked = [...OFFLINE_PERSIST_ROOTS].filter(
+      (root) => !FACTORY_ROOTS.has(root),
+    );
+    expect(unbacked).toEqual([]);
+  });
+});

apps/client/src/features/offline/query-persister.test.ts

@@ -0,0 +1,128 @@
+import { describe, it, expect, vi, afterEach } from "vitest";
+
+// In-memory idb-keyval so we can observe whether the persister actually writes.
+const h = vi.hoisted(() => ({
+  get: vi.fn(() => Promise.resolve(undefined)),
+  set: vi.fn(() => Promise.resolve()),
+  del: vi.fn(() => Promise.resolve()),
+}));
+vi.mock("idb-keyval", () => h);
+
+import {
+  shouldDehydrateOfflineQuery,
+  OFFLINE_PERSIST_ROOTS,
+  queryPersister,
+  freezeOfflinePersistence,
+  unfreezeOfflinePersistence,
+} from "./query-persister";
+
+// Small helper to build the structural query shape the predicate reads.
+const makeQuery = (status: string, queryKey: readonly unknown[]) =>
+  ({ state: { status }, queryKey }) as any;
+
+describe("shouldDehydrateOfflineQuery", () => {
+  it("returns true for a successful query whose root is in the allowlist", () => {
+    expect(shouldDehydrateOfflineQuery(makeQuery("success", ["pages", "abc"]))).toBe(
+      true,
+    );
+    expect(
+      shouldDehydrateOfflineQuery(
+        makeQuery("success", ["sidebar-pages", { pageId: "p", spaceId: "s" }]),
+      ),
+    ).toBe(true);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["comments", "p1"])),
+    ).toBe(true);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["space", "s"])),
+    ).toBe(true);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["recent-changes"])),
+    ).toBe(true);
+    // currentUser is persisted so the auth-gated Layout can hydrate offline.
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["currentUser"])),
+    ).toBe(true);
+  });
+
+  it("returns false when the status is not success (status gate)", () => {
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("pending", ["pages", "abc"])),
+    ).toBe(false);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("error", ["pages", "abc"])),
+    ).toBe(false);
+  });
+
+  it("returns false for a successful query whose root is NOT in the allowlist (privacy gate)", () => {
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["collab-token", "ws"])),
+    ).toBe(false);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["trash", "s"])),
+    ).toBe(false);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["unknown"])),
+    ).toBe(false);
+  });
+
+  it("returns false for an empty/undefined queryKey", () => {
+    // String(undefined) is not a member of the allowlist.
+    expect(shouldDehydrateOfflineQuery(makeQuery("success", []))).toBe(false);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", undefined as any)),
+    ).toBe(false);
+  });
+});
+
+describe("OFFLINE_PERSIST_ROOTS", () => {
+  it("contains exactly the expected 9 navigation/read roots", () => {
+    const expected = [
+      "pages",
+      "sidebar-pages",
+      "root-sidebar-pages",
+      "breadcrumbs",
+      "comments",
+      "space",
+      "spaces",
+      "recent-changes",
+      "currentUser",
+    ];
+    expect(OFFLINE_PERSIST_ROOTS.size).toBe(9);
+    for (const root of expected) {
+      expect(OFFLINE_PERSIST_ROOTS.has(root)).toBe(true);
+    }
+  });
+
+  it("does NOT contain volatile/auth keys", () => {
+    expect(OFFLINE_PERSIST_ROOTS.has("collab-token")).toBe(false);
+    expect(OFFLINE_PERSIST_ROOTS.has("trash")).toBe(false);
+  });
+});
+
+describe("freeze/unfreeze persistence (logout no-late-write guard)", () => {
+  const dummyClient = {
+    timestamp: Date.now(),
+    buster: "",
+    clientState: { mutations: [], queries: [] },
+  } as any;
+
+  afterEach(() => {
+    // Always leave persistence enabled so other tests/sessions persist normally.
+    unfreezeOfflinePersistence();
+    h.set.mockClear();
+  });
+
+  it("does NOT write to storage while frozen", async () => {
+    freezeOfflinePersistence();
+    await queryPersister.persistClient(dummyClient);
+    expect(h.set).not.toHaveBeenCalled();
+  });
+
+  it("resumes writing to storage once unfrozen", async () => {
+    freezeOfflinePersistence();
+    unfreezeOfflinePersistence();
+    await queryPersister.persistClient(dummyClient);
+    expect(h.set).toHaveBeenCalledTimes(1);
+  });
+});

apps/client/src/features/offline/query-persister.ts

@@ -0,0 +1,84 @@
+import { get, set, del } from "idb-keyval";
+import { createAsyncStoragePersister } from "@tanstack/query-async-storage-persister";
+
+// Structural subset of a TanStack Query we read when deciding what to persist.
+// We avoid importing the branded `Query` class because the persist-client and
+// react-query may resolve to different `@tanstack/query-core` copies, whose
+// `Query` types are nominally incompatible (private brand). This structural
+// shape stays assignable to whichever copy the persister expects.
+type DehydratableQuery = {
+  state: { status: string };
+  queryKey: readonly unknown[];
+};
+
+// idb-keyval key under which TanStack Query persists its dehydrated cache.
+// Exported so the logout cache-clear logic deletes the exact same key (no
+// magic-string drift between persist and purge).
+export const OFFLINE_CACHE_KEY = "gitmost-rq-cache";
+
+// IndexedDB-backed storage adapter for TanStack Query's async persister.
+const idbStorage = {
+  getItem: (key: string) => get<string>(key).then((v) => v ?? null),
+  setItem: (key: string, value: string) => set(key, value),
+  removeItem: (key: string) => del(key),
+};
+
+const basePersister = createAsyncStoragePersister({
+  storage: idbStorage,
+  key: OFFLINE_CACHE_KEY,
+  throttleTime: 1000,
+});
+
+// When frozen, persistClient becomes a no-op so no new dehydrated snapshot is
+// written to IndexedDB. This closes a logout data-leak race: clearing the cache
+// (queryClient.clear()) fires `removed` cache events, each of which the persist
+// subscription turns into a throttled persistClient call. The FIRST such call
+// dehydrates a still-nearly-full snapshot and its async write can land AFTER the
+// del() that clears the key, resurrecting the previous user's data (~180KB) in
+// IndexedDB. Freezing before clear()/del() prevents any such rewrite. Re-enabled
+// afterwards so the next (sign-in) session persists normally. See
+// clear-offline-cache.ts.
+let persistFrozen = false;
+
+export function freezeOfflinePersistence(): void {
+  persistFrozen = true;
+}
+
+export function unfreezeOfflinePersistence(): void {
+  persistFrozen = false;
+}
+
+export const queryPersister = {
+  persistClient: (persistedClient: Parameters<typeof basePersister.persistClient>[0]) =>
+    persistFrozen ? Promise.resolve() : basePersister.persistClient(persistedClient),
+  restoreClient: () => basePersister.restoreClient(),
+  removeClient: () => basePersister.removeClient(),
+};
+
+// Only navigation/read query roots are persisted for offline reading.
+// Volatile/auth queries (collab tokens, trash lists) are intentionally excluded.
+//
+// `currentUser` IS persisted: UserProvider gates the entire <Layout> subtree on
+// useCurrentUser(), and offline the POST /api/users/me fails as a no-response
+// network error. Without the persisted/hydrated user the gate blanked every
+// authenticated route on an offline cold boot (#237/#238). It is the logged-in
+// user's own profile (already mirrored to localStorage["currentUser"]), so
+// persisting it to IndexedDB leaks nothing new while unlocking offline reads.
+export const OFFLINE_PERSIST_ROOTS = new Set<string>([
+  "pages",
+  "sidebar-pages",
+  "root-sidebar-pages",
+  "breadcrumbs",
+  "comments",
+  "space",
+  "spaces",
+  "recent-changes",
+  "currentUser",
+]);
+
+export function shouldDehydrateOfflineQuery(query: DehydratableQuery): boolean {
+  return (
+    query.state.status === "success" &&
+    OFFLINE_PERSIST_ROOTS.has(String(query.queryKey?.[0]))
+  );
+}

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

@@ -12,6 +12,8 @@ import {
   IconList,
   IconMarkdown,
   IconPrinter,
+  IconCloud,
+  IconCloudCheck,
   IconStar,
   IconStarFilled,
   IconTrash,
@@ -39,6 +41,8 @@ import { Trans, useTranslation } from "react-i18next";
 import ExportModal from "@/components/common/export-modal";
 import { htmlToMarkdown } from "@docmost/editor-ext";
 import {
+  isLocalSyncedAtom,
+  isRemoteSyncedAtom,
   pageEditorAtom,
   yjsConnectionStatusAtom,
 } from "@/features/editor/atoms/editor-atoms.ts";
@@ -411,14 +415,16 @@ function PageActionMenu({ readOnly }: PageActionMenuProps) {
 function ConnectionWarning() {
   const { t } = useTranslation();
   const yjsConnectionStatus = useAtomValue(yjsConnectionStatusAtom);
+  const isLocalSynced = useAtomValue(isLocalSyncedAtom);
+  const isRemoteSynced = useAtomValue(isRemoteSyncedAtom);
   const [showWarning, setShowWarning] = useState(false);
   const timeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 
-  useEffect(() => {
-    const isDisconnected = ["disconnected", "connecting"].includes(
-      yjsConnectionStatus,
-    );
+  const isDisconnected = ["disconnected", "connecting"].includes(
+    yjsConnectionStatus,
+  );
 
+  useEffect(() => {
     if (isDisconnected) {
       if (!timeoutRef.current) {
         timeoutRef.current = setTimeout(() => setShowWarning(true), 5000);
@@ -430,7 +436,7 @@ function ConnectionWarning() {
       }
       setShowWarning(false);
     }
-  }, [yjsConnectionStatus]);
+  }, [isDisconnected]);
 
   // Cleanup only on unmount
   useEffect(() => {
@@ -441,22 +447,59 @@ function ConnectionWarning() {
     };
   }, []);
 
-  if (!showWarning) return null;
+  // State (1): offline/disconnected — changes are kept locally. Preserve the
+  // existing >5s debounce before surfacing this state.
+  if (isDisconnected) {
+    if (!showWarning) return null;
 
+    const offlineLabel = t(
+      "Offline — changes are saved locally and will sync when you reconnect",
+    );
+    return (
+      <Tooltip label={offlineLabel} openDelay={250} withArrow>
+        <ThemeIcon
+          variant="default"
+          c="red"
+          role="status"
+          aria-label={offlineLabel}
+          style={{ border: "none" }}
+        >
+          <IconWifiOff size={20} stroke={2} />
+        </ThemeIcon>
+      </Tooltip>
+    );
+  }
+
+  // State (2): connected but the remote replica is not fully caught up yet.
+  if (!isRemoteSynced || !isLocalSynced) {
+    const syncingLabel = t("Syncing changes…");
+    return (
+      <Tooltip label={syncingLabel} openDelay={250} withArrow>
+        <ThemeIcon
+          variant="default"
+          c="dimmed"
+          role="status"
+          aria-label={syncingLabel}
+          style={{ border: "none" }}
+        >
+          <IconCloud size={20} stroke={2} />
+        </ThemeIcon>
+      </Tooltip>
+    );
+  }
+
+  // State (3): fully synced — subtle confirmation indicator.
+  const syncedLabel = t("All changes synced");
   return (
-    <Tooltip
-      label={t("Real-time editor connection lost. Retrying...")}
-      openDelay={250}
-      withArrow
-    >
+    <Tooltip label={syncedLabel} openDelay={250} withArrow>
       <ThemeIcon
         variant="default"
-        c="red"
+        c="dimmed"
         role="status"
-        aria-label={t("Real-time editor connection lost. Retrying...")}
+        aria-label={syncedLabel}
         style={{ border: "none" }}
       >
-        <IconWifiOff size={20} stroke={2} />
+        <IconCloudCheck size={20} stroke={2} />
       </ThemeIcon>
     </Tooltip>
   );

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

@@ -1,6 +1,7 @@
 import {
   InfiniteData,
   QueryKey,
+  queryOptions,
   useInfiniteQuery,
   UseInfiniteQueryResult,
   useMutation,
@@ -42,12 +43,38 @@ import { treeModel } from "@/features/page/tree/model/tree-model";
 import { SpaceTreeNode } from "@/features/page/tree/types";
 import { useQueryEmit } from "@/features/websocket/use-query-emit";
 import { moveToTrashNotificationMessage } from "@/features/page/components/move-to-trash-notification";
+import { offlineMutationKeys } from "@/features/offline/offline-mutations";
+
+/**
+ * Centralized React Query key factories for page queries. The hooks below and
+ * the offline warm path (features/offline/make-offline.ts) share these so the
+ * runtime keys can never silently drift apart.
+ */
+export const pageKeys = {
+  detail: (idOrSlug: string) => ["pages", idOrSlug] as const,
+  sidebar: (data: unknown) => ["sidebar-pages", data] as const,
+  rootSidebar: (spaceId: string) => ["root-sidebar-pages", spaceId] as const,
+  breadcrumbs: (pageId: string) => ["breadcrumbs", pageId] as const,
+  recentChanges: (spaceId?: string) => ["recent-changes", spaceId] as const,
+};
+
+/**
+ * Shared queryOptions for the sidebar-pages (ancestor children) query. Both
+ * fetchAllAncestorChildren and the offline warm path consume this so the key,
+ * queryFn and staleTime stay identical.
+ */
+export const sidebarPagesQueryOptions = (params: SidebarPagesParams) =>
+  queryOptions({
+    queryKey: pageKeys.sidebar(params),
+    queryFn: () => getAllSidebarPages(params),
+    staleTime: 30 * 60 * 1000,
+  });
 
 export function usePageQuery(
   pageInput: Partial<IPageInput>,
 ): UseQueryResult<IPage, Error> {
   const query = useQuery({
-    queryKey: ["pages", pageInput.pageId],
+    queryKey: pageKeys.detail(pageInput.pageId),
     queryFn: () => getPageById(pageInput),
     enabled: !!pageInput.pageId,
     staleTime: 5 * 60 * 1000,
@@ -56,9 +83,9 @@ export function usePageQuery(
   useEffect(() => {
     if (query.data) {
       if (isValidUuid(pageInput.pageId)) {
-        queryClient.setQueryData(["pages", query.data.slugId], query.data);
+        queryClient.setQueryData(pageKeys.detail(query.data.slugId), query.data);
       } else {
-        queryClient.setQueryData(["pages", query.data.id], query.data);
+        queryClient.setQueryData(pageKeys.detail(query.data.id), query.data);
       }
     }
   }, [query.data]);
@@ -69,6 +96,10 @@ export function usePageQuery(
 export function useCreatePageMutation() {
   const { t } = useTranslation();
   return useMutation<IPage, Error, Partial<IPageInput>>({
+    // Stable key so a paused create restored from IndexedDB after an offline
+    // reload finds its default mutationFn (registerOfflineMutationDefaults) and
+    // is replayed by resumePausedMutations() on reconnect instead of being lost.
+    mutationKey: offlineMutationKeys.createPage,
     mutationFn: (data) => createPage(data),
     onSuccess: (data) => {
       invalidateOnCreatePage(data);
@@ -80,18 +111,20 @@ export function useCreatePageMutation() {
 }
 
 export function updatePageData(data: IPage) {
-  const pageBySlug = queryClient.getQueryData<IPage>(["pages", data.slugId]);
-  const pageById = queryClient.getQueryData<IPage>(["pages", data.id]);
+  const pageBySlug = queryClient.getQueryData<IPage>(
+    pageKeys.detail(data.slugId),
+  );
+  const pageById = queryClient.getQueryData<IPage>(pageKeys.detail(data.id));
 
   if (pageBySlug) {
-    queryClient.setQueryData(["pages", data.slugId], {
+    queryClient.setQueryData(pageKeys.detail(data.slugId), {
       ...pageBySlug,
       ...data,
     });
   }
 
   if (pageById) {
-    queryClient.setQueryData(["pages", data.id], { ...pageById, ...data });
+    queryClient.setQueryData(pageKeys.detail(data.id), { ...pageById, ...data });
   }
 
   invalidateOnUpdatePage(
@@ -145,11 +178,11 @@ export function useRemovePageMutation() {
       });
 
       // Stamp deletedAt so a re-visit shows the trash banner, not stale state.
-      const cached = queryClient.getQueryData<IPage>(["pages", pageId]);
+      const cached = queryClient.getQueryData<IPage>(pageKeys.detail(pageId));
       if (cached) {
         const stamped = { ...cached, deletedAt: new Date() };
-        queryClient.setQueryData(["pages", cached.id], stamped);
-        queryClient.setQueryData(["pages", cached.slugId], stamped);
+        queryClient.setQueryData(pageKeys.detail(cached.id), stamped);
+        queryClient.setQueryData(pageKeys.detail(cached.slugId), stamped);
       }
 
       invalidateOnDeletePage(pageId);
@@ -188,6 +221,9 @@ export function useDeletePageMutation() {
 
 export function useMovePageMutation() {
   return useMutation<void, Error, IMovePage>({
+    // Stable key so a paused move restored from IndexedDB after an offline
+    // reload finds its default mutationFn and is replayed on reconnect.
+    mutationKey: offlineMutationKeys.movePage,
     mutationFn: (data) => movePage(data),
   });
 }
@@ -267,8 +303,11 @@ export function useRestorePageMutation() {
       // Replace would strip space/permissions/content and break the editor.
       const merge = (cached: IPage | undefined) =>
         cached ? { ...cached, ...restoredPage } : cached;
-      queryClient.setQueryData<IPage>(["pages", restoredPage.id], merge);
-      queryClient.setQueryData<IPage>(["pages", restoredPage.slugId], merge);
+      queryClient.setQueryData<IPage>(pageKeys.detail(restoredPage.id), merge);
+      queryClient.setQueryData<IPage>(
+        pageKeys.detail(restoredPage.slugId),
+        merge,
+      );
     },
     onError: (error) => {
       notifications.show({
@@ -283,7 +322,7 @@ export function useGetSidebarPagesQuery(
   data: SidebarPagesParams | null,
 ): UseInfiniteQueryResult<InfiniteData<IPagination<IPage>, unknown>> {
   return useInfiniteQuery({
-    queryKey: ["sidebar-pages", data],
+    queryKey: pageKeys.sidebar(data),
     enabled: !!data?.pageId || !!data?.spaceId,
     queryFn: ({ pageParam }) =>
       getSidebarPages({ ...data, cursor: pageParam, limit: 100 }),
@@ -294,7 +333,7 @@ export function useGetSidebarPagesQuery(
 
 export function useGetRootSidebarPagesQuery(data: SidebarPagesParams) {
   return useInfiniteQuery({
-    queryKey: ["root-sidebar-pages", data.spaceId],
+    queryKey: pageKeys.rootSidebar(data.spaceId),
     queryFn: async ({ pageParam }) => {
       return getSidebarPages({
         spaceId: data.spaceId,
@@ -320,7 +359,7 @@ export function usePageBreadcrumbsQuery(
   pageId: string,
 ): UseQueryResult<Partial<IPage[]>, Error> {
   return useQuery({
-    queryKey: ["breadcrumbs", pageId],
+    queryKey: pageKeys.breadcrumbs(pageId),
     queryFn: () => getPageBreadcrumbs(pageId),
     enabled: !!pageId,
   });
@@ -332,10 +371,12 @@ export async function fetchAllAncestorChildren(
   // refresh (#159 #8), which must NOT receive the 30-min-cached children.
   opts?: { fresh?: boolean },
 ) {
-  // not using a hook here, so we can call it inside a useEffect hook
+  // not using a hook here, so we can call it inside a useEffect hook. Reuse the
+  // shared sidebarPagesQueryOptions (key + queryFn) so the offline warm path and
+  // this fetch never drift, but override staleTime for the `fresh` reconnect
+  // refresh (#159 #8), which must force a server refetch (staleTime 0).
   const response = await queryClient.fetchQuery({
-    queryKey: ["sidebar-pages", params],
-    queryFn: () => getAllSidebarPages(params),
+    ...sidebarPagesQueryOptions(params),
     staleTime: opts?.fresh ? 0 : 30 * 60 * 1000,
   });
 
@@ -345,7 +386,7 @@ export async function fetchAllAncestorChildren(
 
 export function useRecentChangesQuery(spaceId?: string) {
   return useInfiniteQuery({
-    queryKey: ["recent-changes", spaceId],
+    queryKey: pageKeys.recentChanges(spaceId),
     queryFn: ({ pageParam }) =>
       getRecentChanges({ spaceId, cursor: pageParam, limit: 15 }),
     initialPageParam: undefined as string | undefined,
@@ -416,12 +457,12 @@ export function invalidateOnCreatePage(data: Partial<IPage>) {
 
   let queryKey: QueryKey = null;
   if (data.parentPageId === null) {
-    queryKey = ["root-sidebar-pages", data.spaceId];
+    queryKey = pageKeys.rootSidebar(data.spaceId);
   } else {
-    queryKey = [
-      "sidebar-pages",
-      { pageId: data.parentPageId, spaceId: data.spaceId },
-    ];
+    queryKey = pageKeys.sidebar({
+      pageId: data.parentPageId,
+      spaceId: data.spaceId,
+    });
   }
 
   //update all sidebar pages
@@ -481,7 +522,7 @@ export function invalidateOnCreatePage(data: Partial<IPage>) {
 
     //update root sidebar pages haschildern
     const rootSideBarMatches = queryClient.getQueriesData({
-      queryKey: ["root-sidebar-pages", data.spaceId],
+      queryKey: pageKeys.rootSidebar(data.spaceId),
       exact: false,
     });
 
@@ -505,7 +546,7 @@ export function invalidateOnCreatePage(data: Partial<IPage>) {
 
   //update recent changes
   queryClient.invalidateQueries({
-    queryKey: ["recent-changes", data.spaceId],
+    queryKey: pageKeys.recentChanges(data.spaceId),
   });
 }
 
@@ -519,9 +560,9 @@ export function invalidateOnUpdatePage(
   invalidatePageTree();
   let queryKey: QueryKey = null;
   if (parentPageId === null) {
-    queryKey = ["root-sidebar-pages", spaceId];
+    queryKey = pageKeys.rootSidebar(spaceId);
   } else {
-    queryKey = ["sidebar-pages", { pageId: parentPageId, spaceId: spaceId }];
+    queryKey = pageKeys.sidebar({ pageId: parentPageId, spaceId: spaceId });
   }
   //update all sidebar pages
   queryClient.setQueryData<InfiniteData<IPagination<IPage>>>(
@@ -544,7 +585,7 @@ export function invalidateOnUpdatePage(
 
   //update recent changes
   queryClient.invalidateQueries({
-    queryKey: ["recent-changes", spaceId],
+    queryKey: pageKeys.recentChanges(spaceId),
   });
 }
 
@@ -559,8 +600,8 @@ export function updateCacheOnMovePage(
   // Remove page from old parent's cache
   const oldQueryKey =
     oldParentId === null
-      ? ["root-sidebar-pages", spaceId]
-      : ["sidebar-pages", { pageId: oldParentId, spaceId }];
+      ? pageKeys.rootSidebar(spaceId)
+      : pageKeys.sidebar({ pageId: oldParentId, spaceId });
 
   queryClient.setQueryData<InfiniteData<IPagination<IPage>>>(
     oldQueryKey,
@@ -580,7 +621,7 @@ export function updateCacheOnMovePage(
   if (oldParentId !== null) {
     const oldParentCache = queryClient.getQueryData<
       InfiniteData<IPagination<IPage>>
-    >(["sidebar-pages", { pageId: oldParentId, spaceId }]);
+    >(pageKeys.sidebar({ pageId: oldParentId, spaceId }));
 
     const remainingChildren =
       oldParentCache?.pages.flatMap((p) => p.items).length ?? 0;
@@ -618,8 +659,8 @@ export function updateCacheOnMovePage(
   // Add page to new parent's cache
   const newQueryKey =
     newParentId === null
-      ? ["root-sidebar-pages", spaceId]
-      : ["sidebar-pages", { pageId: newParentId, spaceId }];
+      ? pageKeys.rootSidebar(spaceId)
+      : pageKeys.sidebar({ pageId: newParentId, spaceId });
 
   queryClient.setQueryData<InfiniteData<IPagination<Partial<IPage>>>>(
     newQueryKey,

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

@@ -0,0 +1,199 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { render, screen, fireEvent, waitFor, cleanup } from "@testing-library/react";
+import { MantineProvider } from "@mantine/core";
+
+// --- Mocks for the heavy / networked module graph ---------------------------
+// NodeMenu pulls in query hooks, page services, websocket emit, i18n,
+// notifications and three modal children. The F1 "make available offline"
+// guarantee lives entirely inside handleMakeAvailableOffline, so we mock the
+// two offline helpers + the collab-token hook + notifications and stub away
+// everything else so the menu renders in isolation. matchMedia (read by
+// MantineProvider) is stubbed globally in vitest.setup.ts.
+
+// vi.mock factories are hoisted above imports, so the shared spies they
+// reference must be declared with vi.hoisted (hoisted as well).
+const h = vi.hoisted(() => ({
+  makePageAvailableOffline: vi.fn(),
+  warmPageYdoc: vi.fn(),
+  notificationsShow: vi.fn(),
+}));
+
+vi.mock("@/features/offline/make-offline", () => ({
+  makePageAvailableOffline: (...args: unknown[]) =>
+    h.makePageAvailableOffline(...args),
+  warmPageYdoc: (...args: unknown[]) => h.warmPageYdoc(...args),
+}));
+
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: (...args: unknown[]) => h.notificationsShow(...args) },
+}));
+
+// t is identity so assertions can match the real source strings by key.
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (key: string) => key }),
+}));
+
+vi.mock("react-router-dom", () => ({
+  useParams: () => ({ spaceSlug: "space-slug" }),
+}));
+
+vi.mock("@/features/auth/queries/auth-query.tsx", () => ({
+  useCollabToken: () => ({ data: { token: "collab-token" } }),
+}));
+
+vi.mock("@/lib/config.ts", () => ({
+  getCollaborationUrl: () => "wss://collab.example",
+  getAppUrl: () => "https://app.example",
+}));
+
+vi.mock("@/features/page/tree/hooks/use-tree-mutation.ts", () => ({
+  useTreeMutation: () => ({ handleDelete: vi.fn() }),
+}));
+
+vi.mock("@/features/websocket/use-query-emit.ts", () => ({
+  useQueryEmit: () => vi.fn(),
+}));
+
+vi.mock("@/features/favorite/queries/favorite-query", () => ({
+  useFavoriteIds: () => new Set<string>(),
+  useAddFavoriteMutation: () => ({ mutate: vi.fn() }),
+  useRemoveFavoriteMutation: () => ({ mutate: vi.fn() }),
+}));
+
+vi.mock("@/features/page-embed/queries/page-embed-query", () => ({
+  useToggleTemplateMutation: () => ({ mutateAsync: vi.fn() }),
+  useToggleTemporaryMutation: () => ({ mutateAsync: vi.fn() }),
+}));
+
+vi.mock("@/features/page/services/page-service.ts", () => ({
+  duplicatePage: vi.fn(),
+}));
+
+// The modal children drag in export / move / copy stacks we never exercise.
+vi.mock("@/components/common/export-modal", () => ({ default: () => null }));
+vi.mock("@/features/page/components/move-page-modal.tsx", () => ({
+  default: () => null,
+}));
+vi.mock("@/features/page/components/copy-page-modal.tsx", () => ({
+  default: () => null,
+}));
+
+import { NodeMenu } from "./space-tree-node-menu";
+import type { SpaceTreeNode } from "@/features/page/tree/types.ts";
+
+function node(): SpaceTreeNode {
+  return {
+    id: "page-1",
+    slugId: "slug-1",
+    name: "My Page",
+    icon: undefined,
+    position: "a0",
+    spaceId: "space-1",
+    parentPageId: null as unknown as string,
+    hasChildren: false,
+    children: [],
+  };
+}
+
+function renderMenu() {
+  render(
+    <MantineProvider>
+      <NodeMenu node={node()} canEdit={true} />
+    </MantineProvider>,
+  );
+}
+
+// Open the menu (click the dots target) and click "Make available offline".
+async function triggerMakeAvailableOffline() {
+  // Before opening, the only button is the menu target ActionIcon.
+  fireEvent.click(screen.getByRole("button"));
+  const item = await screen.findByText("Make available offline");
+  fireEvent.click(item);
+}
+
+// The handler always fires a leading "Saving page for offline use..." toast and
+// then the result/error toast — so the LAST show() call is the outcome we pin.
+function lastShown(): { message?: string; color?: string } {
+  const calls = h.notificationsShow.mock.calls;
+  return calls[calls.length - 1]?.[0] ?? {};
+}
+
+beforeEach(() => {
+  h.makePageAvailableOffline.mockReset();
+  h.warmPageYdoc.mockReset();
+  h.notificationsShow.mockReset();
+});
+
+afterEach(() => {
+  cleanup();
+});
+
+describe("NodeMenu — make available offline (F1 guarantee)", () => {
+  it("full success: read queries warmed AND ydoc synced → success toast with no error color", async () => {
+    h.makePageAvailableOffline.mockResolvedValue({ ok: true, failed: [] });
+    h.warmPageYdoc.mockResolvedValue(true);
+
+    renderMenu();
+    await triggerMakeAvailableOffline();
+
+    await waitFor(() => {
+      expect(lastShown().message).toBe("Page is now available offline");
+    });
+    // Success path: no red color (the gate `result.ok && ydocSynced` held).
+    expect(lastShown().color).toBeUndefined();
+    // warmPageYdoc was consulted with the page id, collab url and token.
+    expect(h.warmPageYdoc).toHaveBeenCalledWith(
+      "page-1",
+      "wss://collab.example",
+      "collab-token",
+    );
+  });
+
+  it("ydoc NOT synced: read queries ok but warmPageYdoc=false → RED toast naming 'editor'", async () => {
+    // F1: a page whose editor body never landed in IndexedDB must NOT be
+    // reported as available offline, even though every read query succeeded.
+    h.makePageAvailableOffline.mockResolvedValue({ ok: true, failed: [] });
+    h.warmPageYdoc.mockResolvedValue(false);
+
+    renderMenu();
+    await triggerMakeAvailableOffline();
+
+    await waitFor(() => {
+      expect(lastShown().color).toBe("red");
+    });
+    expect(lastShown().message).toContain("editor");
+    expect(lastShown().message).not.toBe("Page is now available offline");
+  });
+
+  it("read-query failures: failed=['page','comments'] → RED toast naming the failed steps", async () => {
+    h.makePageAvailableOffline.mockResolvedValue({
+      ok: false,
+      failed: ["page", "comments"],
+    });
+    h.warmPageYdoc.mockResolvedValue(true);
+
+    renderMenu();
+    await triggerMakeAvailableOffline();
+
+    await waitFor(() => {
+      expect(lastShown().color).toBe("red");
+    });
+    expect(lastShown().message).toContain("page");
+    expect(lastShown().message).toContain("comments");
+  });
+
+  it("thrown error: rejection's response.data.message is extracted into the RED toast", async () => {
+    h.makePageAvailableOffline.mockRejectedValue({
+      response: { data: { message: "boom" } },
+    });
+    h.warmPageYdoc.mockResolvedValue(true);
+
+    renderMenu();
+    await triggerMakeAvailableOffline();
+
+    await waitFor(() => {
+      expect(lastShown().color).toBe("red");
+    });
+    expect(lastShown().message).toContain("boom");
+  });
+});

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

@@ -7,6 +7,7 @@ import { notifications } from "@mantine/notifications";
 import {
   IconArrowRight,
   IconClockHour4,
+  IconCloudDownload,
   IconCopy,
   IconDotsVertical,
   IconFileExport,
@@ -35,6 +36,12 @@ import {
   useToggleTemplateMutation,
   useToggleTemporaryMutation,
 } from "@/features/page-embed/queries/page-embed-query";
+import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
+import { getCollaborationUrl } from "@/lib/config.ts";
+import {
+  makePageAvailableOffline,
+  warmPageYdoc,
+} from "@/features/offline/make-offline";
 import { treeDataAtom } from "@/features/page/tree/atoms/tree-data-atom.ts";
 import { treeModel } from "@/features/page/tree/model/tree-model";
 import { pageToTreeNode } from "@/features/page/tree/utils";
@@ -72,6 +79,57 @@ export function NodeMenu({ node, canEdit }: NodeMenuProps) {
   const isTemplate = !!node.isTemplate;
   const toggleTemporary = useToggleTemporaryMutation();
   const isTemporary = !!node.temporaryExpiresAt;
+  const { data: collabQuery } = useCollabToken();
+
+  const handleMakeAvailableOffline = async () => {
+    notifications.show({ message: t("Saving page for offline use...") });
+    try {
+      // Prefetch read queries so they get persisted to IndexedDB. The result
+      // reports whether every warm step succeeded.
+      const result = await makePageAvailableOffline({
+        pageId: node.id,
+        spaceId: node.spaceId,
+      });
+      // Warm the page's Yjs document into IndexedDB. For a wiki the editor body
+      // IS the page, so this only truly succeeds when the doc actually synced;
+      // a timeout/failure here must NOT be reported as offline-available.
+      const ydocSynced = await warmPageYdoc(
+        node.id,
+        getCollaborationUrl(),
+        collabQuery?.token,
+      );
+
+      // Fold a failed editor warm into the failed-step set so it surfaces in the
+      // same error UI as the read-query failures (the editor body never landed
+      // in IndexedDB, so the page would open blank offline).
+      const failed = ydocSynced ? result.failed : [...result.failed, "editor"];
+
+      if (result.ok && ydocSynced) {
+        notifications.show({ message: t("Page is now available offline") });
+      } else {
+        // Partial warm — the page may still be partly usable offline, but some
+        // queries (or the editor body) failed to cache, so surface it as an
+        // error rather than a silent success. Name the failed step(s) (AGENTS.md:
+        // errors must be specific, never a bare generic string).
+        notifications.show({
+          message: `${t("Failed to make page available offline")}: ${failed.join(", ")}`,
+          color: "red",
+        });
+      }
+    } catch (err) {
+      // makePageAvailableOffline no longer throws, but warmPageYdoc and other
+      // unexpected failures stay guarded here. Log the raw error and surface the
+      // real cause to the user instead of a bare generic string (AGENTS.md).
+      console.error("handleMakeAvailableOffline failed", err);
+      const reason =
+        (err as { response?: { data?: { message?: string } } })?.response?.data
+          ?.message ?? (err instanceof Error ? err.message : String(err));
+      notifications.show({
+        message: `${t("Failed to make page available offline")}: ${reason}`,
+        color: "red",
+      });
+    }
+  };
 
   const handleToggleTemplate = async () => {
     const next = !isTemplate;
@@ -228,6 +286,17 @@ export function NodeMenu({ node, canEdit }: NodeMenuProps) {
             {t("Export")}
           </Menu.Item>
 
+          <Menu.Item
+            leftSection={<IconCloudDownload size={16} />}
+            onClick={(e) => {
+              e.preventDefault();
+              e.stopPropagation();
+              handleMakeAvailableOffline();
+            }}
+          >
+            {t("Make available offline")}
+          </Menu.Item>
+
           {canEdit && (
             <>
               <Menu.Item

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

@@ -15,7 +15,6 @@ import {
   useCreatePageMutation,
   useRemovePageMutation,
   useMovePageMutation,
-  useUpdatePageMutation,
   updateCacheOnMovePage,
 } from "@/features/page/queries/page-query.ts";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
@@ -27,7 +26,6 @@ export type UseTreeMutation = {
     parentId: string | null,
     opts?: { temporary?: boolean },
   ) => Promise<void>;
-  handleRename: (id: string, name: string) => Promise<void>;
   handleDelete: (id: string) => Promise<void>;
 };
 
@@ -39,7 +37,6 @@ export function useTreeMutation(spaceId: string): UseTreeMutation {
   // children) and then immediately invokes a handler.
   const store = useStore();
   const createPageMutation = useCreatePageMutation();
-  const updatePageMutation = useUpdatePageMutation();
   const removePageMutation = useRemovePageMutation();
   const movePageMutation = useMovePageMutation();
   const navigate = useNavigate();
@@ -205,20 +202,6 @@ export function useTreeMutation(spaceId: string): UseTreeMutation {
     [spaceId, createPageMutation, setData, store, navigate, spaceSlug],
   );
 
-  const handleRename = useCallback(
-    async (id: string, name: string) => {
-      setData((prev) =>
-        treeModel.update(prev, id, { name } as Partial<SpaceTreeNode>),
-      );
-      try {
-        await updatePageMutation.mutateAsync({ pageId: id, title: name });
-      } catch (error) {
-        console.error("Error updating page title:", error);
-      }
-    },
-    [updatePageMutation, setData],
-  );
-
   const handleDelete = useCallback(
     async (id: string) => {
       const node = treeModel.find(
@@ -264,7 +247,7 @@ export function useTreeMutation(spaceId: string): UseTreeMutation {
     [removePageMutation, setData, store, pageSlug, navigate, spaceSlug],
   );
 
-  return { handleMove, handleCreate, handleRename, handleDelete };
+  return { handleMove, handleCreate, handleDelete };
 }
 
 function isPageInNode(node: SpaceTreeNode, pageSlug: string): boolean {

apps/client/src/features/page/tree/utils/find-breadcrumb-path.test.ts

@@ -0,0 +1,79 @@
+import { describe, it, expect } from "vitest";
+import { findBreadcrumbPath } from "./utils";
+import type { SpaceTreeNode } from "@/features/page/tree/types.ts";
+
+// findBreadcrumbPath walks the live, SHARED sidebar tree. The high-value
+// invariant: when a node has no usable name it must surface "Untitled" ONLY on
+// the returned breadcrumb chain via a shallow copy — never by mutating the input
+// node (which would silently rename the node in the sidebar). Also covers normal
+// ancestor-chain resolution, the not-found case, and nested children.
+
+function node(id: string, over: Partial<SpaceTreeNode> = {}): SpaceTreeNode {
+  return {
+    id,
+    slugId: `slug-${id}`,
+    name: id.toUpperCase(),
+    icon: undefined,
+    position: "a0",
+    spaceId: "space-1",
+    parentPageId: null as unknown as string,
+    hasChildren: false,
+    children: [],
+    ...over,
+  };
+}
+
+describe("findBreadcrumbPath", () => {
+  it("does NOT mutate the input tree when a node has an empty/whitespace name", () => {
+    // A whitespace-only-named node nested under a blank-named root.
+    const target = node("target", { name: "   " });
+    const root = node("root", { name: "", hasChildren: true, children: [target] });
+    const tree = [root];
+
+    const result = findBreadcrumbPath(tree, "target");
+
+    expect(result).not.toBeNull();
+    // The RETURNED chain shows "Untitled" for both blank nodes.
+    expect(result!.map((n) => n.name)).toEqual(["Untitled", "Untitled"]);
+    // The original input nodes are untouched (still blank).
+    expect(root.name).toBe("");
+    expect(target.name).toBe("   ");
+    // The renamed breadcrumb entries are fresh copies, not the input objects.
+    expect(result![0]).not.toBe(root);
+    expect(result![1]).not.toBe(target);
+  });
+
+  it("returns the SAME node reference (no copy) when the name is non-empty", () => {
+    // No rename needed -> the node is passed through by reference (cheap path).
+    const target = node("target", { name: "Real Title" });
+    const result = findBreadcrumbPath([target], "target");
+    expect(result![0]).toBe(target);
+    expect(result![0].name).toBe("Real Title");
+  });
+
+  it("resolves the full ancestor chain ending at the target", () => {
+    const target = node("c");
+    const mid = node("b", { hasChildren: true, children: [target] });
+    const root = node("a", { hasChildren: true, children: [mid] });
+    const result = findBreadcrumbPath([root], "c");
+    expect(result!.map((n) => n.id)).toEqual(["a", "b", "c"]);
+  });
+
+  it("finds a target nested under a deeper sibling branch", () => {
+    // Two root branches; the target lives inside the second branch's child.
+    const target = node("deep");
+    const branch2 = node("r2", {
+      hasChildren: true,
+      children: [node("x"), node("y", { hasChildren: true, children: [target] })],
+    });
+    const branch1 = node("r1", { hasChildren: true, children: [node("z")] });
+    const result = findBreadcrumbPath([branch1, branch2], "deep");
+    expect(result!.map((n) => n.id)).toEqual(["r2", "y", "deep"]);
+  });
+
+  it("returns null when the page id is not present in the tree", () => {
+    const root = node("root", { hasChildren: true, children: [node("child")] });
+    expect(findBreadcrumbPath([root], "missing")).toBeNull();
+    expect(findBreadcrumbPath([], "anything")).toBeNull();
+  });
+});

apps/client/src/features/page/tree/utils/utils.test.ts

@@ -8,6 +8,8 @@ import {
   closeIds,
   mergeRootTrees,
   loadedOpenBranchIds,
+  sortPositionKeys,
+  pageToTreeNode,
 } from "./utils";
 import type { IPage } from "@/features/page/types/page.types.ts";
 import type { SpaceTreeNode } from "@/features/page/tree/types.ts";
@@ -60,6 +62,82 @@ function treeNode(id: string, children: SpaceTreeNode[] = []): SpaceTreeNode {
   };
 }
 
+describe("sortPositionKeys", () => {
+  it("orders items ascending by their fractional `position` string", () => {
+    const items = [
+      { id: "c", position: "a5" },
+      { id: "a", position: "a1" },
+      { id: "b", position: "a3" },
+    ];
+    expect(sortPositionKeys(items).map((i) => i.id)).toEqual(["a", "b", "c"]);
+  });
+
+  it("is a stable sort: equal positions keep their input order", () => {
+    const items = [
+      { id: "x", position: "a1" },
+      { id: "y", position: "a1" },
+      { id: "z", position: "a1" },
+    ];
+    expect(sortPositionKeys(items).map((i) => i.id)).toEqual(["x", "y", "z"]);
+  });
+});
+
+describe("pageToTreeNode", () => {
+  function pageRow(over: Partial<IPage> = {}): IPage {
+    return {
+      id: "p1",
+      slugId: "slug-p1",
+      title: "My Page",
+      icon: "📄",
+      position: "a1",
+      hasChildren: true,
+      spaceId: "space-1",
+      parentPageId: null as unknown as string,
+      ...over,
+    } as IPage;
+  }
+
+  it("maps page.title -> node.name and copies the core fields", () => {
+    const node = pageToTreeNode(pageRow());
+    // The non-trivial transform: a page's `title` becomes the tree node's `name`.
+    expect(node.name).toBe("My Page");
+    expect(node.id).toBe("p1");
+    expect(node.slugId).toBe("slug-p1");
+    expect(node.icon).toBe("📄");
+    expect(node.position).toBe("a1");
+    expect(node.spaceId).toBe("space-1");
+    expect(node.hasChildren).toBe(true);
+    // Always materialized with an empty children array.
+    expect(node.children).toEqual([]);
+  });
+
+  it("derives canEdit from page.permissions.canEdit when the flat field is absent", () => {
+    const node = pageToTreeNode(
+      pageRow({ canEdit: undefined, permissions: { canEdit: true } } as Partial<IPage>),
+    );
+    expect(node.canEdit).toBe(true);
+  });
+
+  it("prefers the flat page.canEdit over permissions.canEdit", () => {
+    const node = pageToTreeNode(
+      pageRow({ canEdit: false, permissions: { canEdit: true } } as Partial<IPage>),
+    );
+    expect(node.canEdit).toBe(false);
+  });
+
+  it("carries temporaryExpiresAt straight off the page", () => {
+    const expiresAt = "2026-06-27T21:00:00.000Z";
+    expect(pageToTreeNode(pageRow({ temporaryExpiresAt: expiresAt })).temporaryExpiresAt).toBe(
+      expiresAt,
+    );
+  });
+
+  it("applies overrides on top of the mapped fields (e.g. optimistic blank name)", () => {
+    const node = pageToTreeNode(pageRow(), { name: "" });
+    expect(node.name).toBe("");
+  });
+});
+
 describe("buildTree", () => {
   it("builds one node per unique page", () => {
     const tree = buildTree([page("a", "a1"), page("b", "a2")]);

apps/client/src/features/page/tree/utils/utils.ts

@@ -70,18 +70,22 @@ export function findBreadcrumbPath(
   path: SpaceTreeNode[] = [],
 ): SpaceTreeNode[] | null {
   for (const node of tree) {
-    if (!node.name || node.name.trim() === "") {
-      node.name = "Untitled";
-    }
+    // Never mutate the input tree (it is the live, shared sidebar tree state).
+    // When a node has no usable name, surface "Untitled" via a shallow copy that
+    // only the returned breadcrumb chain sees — the source node stays untouched.
+    const displayNode: SpaceTreeNode =
+      !node.name || node.name.trim() === ""
+        ? { ...node, name: "Untitled" }
+        : node;
 
     if (node.id === pageId) {
-      return [...path, node];
+      return [...path, displayNode];
     }
 
     if (node.children) {
       const newPath = findBreadcrumbPath(node.children, pageId, [
         ...path,
-        node,
+        displayNode,
       ]);
       if (newPath) {
         return newPath;

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

@@ -1,5 +1,6 @@
 import {
   keepPreviousData,
+  queryOptions,
   useInfiniteQuery,
   useMutation,
   useQuery,
@@ -31,11 +32,37 @@ import { getRecentChanges } from "@/features/page/services/page-service.ts";
 import { useEffect } from "react";
 import { validate as isValidUuid } from "uuid";
 
+/**
+ * Centralized React Query key factories for space queries. The hooks below and
+ * the offline warm path (features/offline/make-offline.ts) share these so the
+ * runtime keys can never silently drift apart.
+ */
+export const spaceKeys = {
+  detail: (idOrSlug: string) => ["space", idOrSlug] as const,
+  list: (params?: QueryParams) => ["spaces", params] as const,
+  members: (spaceId: string, query?: string) =>
+    ["spaceMembers", spaceId, query] as const,
+};
+
+/**
+ * Shared queryOptions for fetching a space by id/slug. Both
+ * useGetSpaceBySlugQuery and the offline warm path consume this so the key,
+ * queryFn and staleTime stay identical. (`enabled` is intentionally omitted —
+ * prefetchQuery ignores it anyway and the warm path always passes a real id;
+ * the hook reapplies `enabled` itself.)
+ */
+export const spaceByIdQueryOptions = (spaceId: string) =>
+  queryOptions({
+    queryKey: spaceKeys.detail(spaceId),
+    queryFn: () => getSpaceById(spaceId),
+    staleTime: 5 * 60 * 1000,
+  });
+
 export function useGetSpacesQuery(
   params?: QueryParams,
 ): UseQueryResult<IPagination<ISpace>, Error> {
   return useQuery({
-    queryKey: ["spaces", params],
+    queryKey: spaceKeys.list(params),
     queryFn: () => getSpaces(params),
     placeholderData: keepPreviousData,
     refetchOnMount: true,
@@ -44,16 +71,16 @@ export function useGetSpacesQuery(
 
 export function useSpaceQuery(spaceId: string): UseQueryResult<ISpace, Error> {
   const query = useQuery({
-    queryKey: ["space", spaceId],
+    queryKey: spaceKeys.detail(spaceId),
     queryFn: () => getSpaceById(spaceId),
     enabled: !!spaceId,
   });
   useEffect(() => {
     if (query.data) {
       if (isValidUuid(spaceId)) {
-        queryClient.setQueryData(["space", query.data.slug], query.data);
+        queryClient.setQueryData(spaceKeys.detail(query.data.slug), query.data);
       } else {
-        queryClient.setQueryData(["space", query.data.id], query.data);
+        queryClient.setQueryData(spaceKeys.detail(query.data.id), query.data);
       }
     }
   }, [query.data]);
@@ -62,8 +89,11 @@ export function useSpaceQuery(spaceId: string): UseQueryResult<ISpace, Error> {
 }
 
 export const prefetchSpace = (spaceSlug: string, spaceId?: string) => {
+  // Note: intentionally NOT using spaceByIdQueryOptions here — that factory sets
+  // a 5min staleTime which would let this prefetch skip fetching fresh data;
+  // prefetchSpace must always refetch (default staleTime: 0).
   queryClient.prefetchQuery({
-    queryKey: ["space", spaceSlug],
+    queryKey: spaceKeys.detail(spaceSlug),
     queryFn: () => getSpaceById(spaceSlug),
   });
 
@@ -100,10 +130,8 @@ export function useGetSpaceBySlugQuery(
   spaceId: string,
 ): UseQueryResult<ISpace, Error> {
   return useQuery({
-    queryKey: ["space", spaceId],
-    queryFn: () => getSpaceById(spaceId),
+    ...spaceByIdQueryOptions(spaceId),
     enabled: !!spaceId,
-    staleTime: 5 * 60 * 1000,
   });
 }
 
@@ -116,14 +144,16 @@ export function useUpdateSpaceMutation() {
     onSuccess: (data, variables) => {
       notifications.show({ message: t("Space updated successfully") });
 
-      const space = queryClient.getQueryData([
-        "space",
-        variables.spaceId,
-      ]) as ISpace;
+      const space = queryClient.getQueryData(
+        spaceKeys.detail(variables.spaceId),
+      ) as ISpace;
       if (space) {
         const updatedSpace = { ...space, ...data };
-        queryClient.setQueryData(["space", variables.spaceId], updatedSpace);
-        queryClient.setQueryData(["space", data.slug], updatedSpace);
+        queryClient.setQueryData(
+          spaceKeys.detail(variables.spaceId),
+          updatedSpace,
+        );
+        queryClient.setQueryData(spaceKeys.detail(data.slug), updatedSpace);
       }
 
       queryClient.invalidateQueries({
@@ -148,7 +178,7 @@ export function useDeleteSpaceMutation() {
 
       if (variables.slug) {
         queryClient.removeQueries({
-          queryKey: ["space", variables.slug],
+          queryKey: spaceKeys.detail(variables.slug),
           exact: true,
         });
       }
@@ -156,7 +186,7 @@ export function useDeleteSpaceMutation() {
       // Remove space-specific queries
       if (variables.id) {
         queryClient.removeQueries({
-          queryKey: ["space", variables.id],
+          queryKey: spaceKeys.detail(variables.id),
           exact: true,
         });
 
@@ -196,7 +226,7 @@ export function useSpaceMembersInfiniteQuery(
   query?: string,
 ) {
   return useInfiniteQuery({
-    queryKey: ["spaceMembers", spaceId, query],
+    queryKey: spaceKeys.members(spaceId, query),
     queryFn: ({ pageParam }) =>
       getSpaceMembers(spaceId, { cursor: pageParam, limit: 50, query }),
     enabled: !!spaceId,

apps/client/src/features/user/hooks/use-current-user.ts

@@ -2,9 +2,19 @@ import { useQuery, UseQueryResult } from "@tanstack/react-query";
 import { getMyInfo } from "@/features/user/services/user-service";
 import { ICurrentUser } from "@/features/user/types/user.types";
 
+/**
+ * Centralized React Query key factory for current-user queries. This hook and
+ * the offline warm path (features/offline/make-offline.ts) share it so the
+ * runtime key can never silently drift, and the OFFLINE_PERSIST_ROOTS guard
+ * test can assert the persisted "currentUser" root maps to a real factory.
+ */
+export const userKeys = {
+  currentUser: () => ["currentUser"] as const,
+};
+
 export default function useCurrentUser(): UseQueryResult<ICurrentUser> {
   return useQuery({
-    queryKey: ["currentUser"],
+    queryKey: userKeys.currentUser(),
     queryFn: async () => {
       return await getMyInfo();
     },

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

@@ -0,0 +1,118 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen } from "@testing-library/react";
+import { MantineProvider } from "@mantine/core";
+import { MemoryRouter } from "react-router-dom";
+import { HelmetProvider } from "react-helmet-async";
+
+// Control useCurrentUser per test; stub the rest of UserProvider's network/
+// socket dependencies so we only exercise its render-gating logic.
+const h = vi.hoisted(() => ({ useCurrentUser: vi.fn() }));
+
+vi.mock("@/features/user/hooks/use-current-user", () => ({
+  default: h.useCurrentUser,
+}));
+vi.mock("@/features/auth/queries/auth-query.tsx", () => ({
+  useCollabToken: () => ({ data: undefined }),
+}));
+vi.mock("@/features/websocket/use-query-subscription.ts", () => ({
+  useQuerySubscription: () => {},
+}));
+vi.mock("@/features/websocket/use-tree-socket.ts", () => ({
+  useTreeSocket: () => {},
+}));
+vi.mock("@/features/notification/hooks/use-notification-socket.ts", () => ({
+  useNotificationSocket: () => {},
+}));
+vi.mock("@/main.tsx", () => ({ queryClient: {} }));
+vi.mock("@/features/user/connect-resync.ts", () => ({
+  makeConnectHandler: () => () => {},
+}));
+vi.mock("socket.io-client", () => ({
+  io: () => ({ on: vi.fn(), disconnect: vi.fn() }),
+}));
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({
+    t: (k: string) => k,
+    i18n: {
+      changeLanguage: vi.fn(),
+      language: "en-US",
+      resolvedLanguage: "en-US",
+    },
+  }),
+}));
+
+import { UserProvider } from "./user-provider";
+
+const networkError = { message: "Network Error" }; // axios network error: no `response`
+
+function renderProvider() {
+  return render(
+    <HelmetProvider>
+      <MemoryRouter>
+        <MantineProvider>
+          <UserProvider>
+            <div data-testid="app-child">app content</div>
+          </UserProvider>
+        </MantineProvider>
+      </MemoryRouter>
+    </HelmetProvider>,
+  );
+}
+
+beforeEach(() => {
+  h.useCurrentUser.mockReset();
+});
+
+describe("UserProvider offline render-gating", () => {
+  it("renders the app (cached children) when useCurrentUser errors offline but a cached user exists", () => {
+    // Offline reload: the persisted ['currentUser'] cache hydrates `data`, but
+    // the background POST /api/users/me refetch fails as a network error.
+    h.useCurrentUser.mockReturnValue({
+      data: {
+        user: { id: "u1", locale: "en" },
+        workspace: { id: "w1" },
+      },
+      isLoading: false,
+      error: networkError,
+      isError: true,
+    });
+
+    renderProvider();
+
+    // The cached app must render — NOT a blank fragment (#237/#238).
+    expect(screen.getByTestId("app-child")).toBeDefined();
+    expect(screen.queryByText("You're offline")).toBeNull();
+  });
+
+  it("renders the offline fallback (not a blank fragment) when erroring with no cached user", () => {
+    h.useCurrentUser.mockReturnValue({
+      data: undefined,
+      isLoading: false,
+      error: networkError,
+      isError: true,
+    });
+
+    const { container } = renderProvider();
+
+    // Previously this returned `<></>` — a blank white screen. Now it must show
+    // an explicit offline fallback.
+    expect(screen.getByText("You're offline")).toBeDefined();
+    expect(screen.queryByTestId("app-child")).toBeNull();
+    expect(container.textContent?.length).toBeGreaterThan(0);
+  });
+
+  it("renders the app normally on a successful currentUser load", () => {
+    h.useCurrentUser.mockReturnValue({
+      data: {
+        user: { id: "u1", locale: "en" },
+        workspace: { id: "w1" },
+      },
+      isLoading: false,
+      error: null,
+      isError: false,
+    });
+
+    renderProvider();
+    expect(screen.getByTestId("app-child")).toBeDefined();
+  });
+});

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

@@ -11,6 +11,7 @@ import { useTreeSocket } from "@/features/websocket/use-tree-socket.ts";
 import { useNotificationSocket } from "@/features/notification/hooks/use-notification-socket.ts";
 import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
 import { Error404 } from "@/components/ui/error-404.tsx";
+import { OfflineFallback } from "@/features/offline/offline-fallback.tsx";
 import { queryClient } from "@/main.tsx";
 import { makeConnectHandler } from "@/features/user/connect-resync.ts";
 
@@ -70,14 +71,30 @@ export function UserProvider({ children }: React.PropsWithChildren) {
     document.documentElement.lang = i18n.resolvedLanguage || i18n.language || "en-US";
   }, [i18n.language, i18n.resolvedLanguage]);
 
-  if (isLoading) return <></>;
+  // First load with no cached user yet: render nothing briefly while the
+  // persisted ['currentUser'] cache hydrates (avoids flashing the offline
+  // fallback before restore). Once we have a user we render the app even if a
+  // refetch is still in flight.
+  if (isLoading && !data) return <></>;
 
   if (isError && error?.["response"]?.status === 404) {
     return <Error404 />;
   }
 
+  // We have a (possibly cached/stale) user — render the app. Offline, the
+  // POST /api/users/me refetch fails as a network error, but the persisted/
+  // hydrated user is enough to render the cached UI. Previously `if (error)
+  // return <></>` blanked every authenticated route on an offline reload even
+  // though the cached data was present (#237/#238).
+  if (data) {
+    return <>{children}</>;
+  }
+
+  // No user AND an error (offline cold boot of a page never warmed for offline,
+  // or no persisted cache to restore): show an explicit offline fallback rather
+  // than a blank white screen.
   if (error) {
-    return <></>;
+    return <OfflineFallback />;
   }
 
   return <>{children}</>;

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

@@ -3,6 +3,7 @@ import {
   applyAddTreeNode,
   applyMoveTreeNode,
   applyDeleteTreeNode,
+  applyUpdateOne,
 } from "./tree-socket-reducers";
 import { treeModel } from "@/features/page/tree/model/tree-model";
 import { SpaceTreeNode } from "@/features/page/tree/types.ts";
@@ -338,3 +339,76 @@ describe("applyAddTreeNode", () => {
     expect(treeModel.find(next, "temp")?.temporaryExpiresAt).toBe(expiresAt);
   });
 });
+
+describe("applyUpdateOne", () => {
+  // A loaded two-level tree so we can patch both a root and a nested node.
+  const buildTree = (): SpaceTreeNode[] => [
+    node("root", {
+      position: "a0",
+      name: "Root",
+      icon: "📁",
+      hasChildren: true,
+      children: [node("child", { position: "a1", parentPageId: "root", name: "Child", icon: "📄" })],
+    }),
+  ];
+
+  // Build the UpdateEvent envelope; only `id`/`payload` matter to the reducer.
+  const ev = (id: string, payload: Record<string, unknown>) =>
+    ({
+      operation: "updateOne",
+      spaceId: "space-1",
+      entity: ["pages"],
+      id,
+      payload,
+    }) as unknown as Parameters<typeof applyUpdateOne>[1];
+
+  it("applies a title-only update to the node's name (icon untouched)", () => {
+    const tree = buildTree();
+    const next = applyUpdateOne(tree, ev("child", { title: "Renamed" }));
+    const child = treeModel.find(next, "child");
+    expect(child?.name).toBe("Renamed");
+    // Icon is left as it was.
+    expect(child?.icon).toBe("📄");
+  });
+
+  it("applies an icon-only update to the node's icon (name untouched)", () => {
+    const tree = buildTree();
+    const next = applyUpdateOne(tree, ev("root", { icon: "🔥" }));
+    const root = treeModel.find(next, "root");
+    expect(root?.icon).toBe("🔥");
+    expect(root?.name).toBe("Root");
+  });
+
+  it("applies a combined title + icon update", () => {
+    const tree = buildTree();
+    const next = applyUpdateOne(tree, ev("child", { title: "Both", icon: "⭐" }));
+    const child = treeModel.find(next, "child");
+    expect(child?.name).toBe("Both");
+    expect(child?.icon).toBe("⭐");
+  });
+
+  it("returns prev UNCHANGED (same reference) when the id is not loaded", () => {
+    const tree = buildTree();
+    const next = applyUpdateOne(tree, ev("ghost", { title: "Nope" }));
+    expect(next).toBe(tree);
+  });
+
+  it("returns prev UNCHANGED (same reference) for a no-op payload (no title/icon)", () => {
+    // The node exists, but the payload carries neither title nor icon -> nothing
+    // to patch, so the reducer must hand back the same array reference.
+    const tree = buildTree();
+    const next = applyUpdateOne(tree, ev("child", {}));
+    expect(next).toBe(tree);
+  });
+
+  it("treats an explicit null icon/title as a value to apply (undefined check, not truthiness)", () => {
+    // The reducer guards on `!== undefined`, so a clearing null IS applied.
+    const tree = buildTree();
+    const next = applyUpdateOne(tree, ev("child", { title: "", icon: null }));
+    const child = treeModel.find(next, "child");
+    expect(child?.name).toBe("");
+    expect(child?.icon).toBeNull();
+    // And it did change something -> a fresh reference, not prev.
+    expect(next).not.toBe(tree);
+  });
+});

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

@@ -3,6 +3,9 @@ import {
   resolveCardStatus,
   isEndpointConfigured,
   resolveKeyField,
+  nextReindexPollInterval,
+  isReindexComplete,
+  isReindexButtonLoading,
 } from './ai-provider-settings';
 
 describe('resolveCardStatus', () => {
@@ -71,3 +74,152 @@ describe('resolveKeyField (write-only key payload)', () => {
     expect(resolveKeyField('', false)).toEqual({ set: false });
   });
 });
+
+describe('nextReindexPollInterval', () => {
+  const INTERVAL = 5000;
+  const base = { now: 1_000, intervalMs: INTERVAL };
+
+  it('does not poll when no reindex deadline is set', () => {
+    expect(
+      nextReindexPollInterval({
+        ...base,
+        deadline: null,
+        status: { reindexing: true, indexedPages: 0, totalPages: 478 },
+      }),
+    ).toBe(false);
+  });
+
+  it('keeps polling while the server reports an active run', () => {
+    expect(
+      nextReindexPollInterval({
+        ...base,
+        deadline: 10_000,
+        status: { reindexing: true, indexedPages: 120, totalPages: 478 },
+      }),
+    ).toBe(INTERVAL);
+  });
+
+  it('keeps polling during an active run even if counts momentarily look full', () => {
+    // The run clears its progress record only at the very end, so a transient
+    // indexed==total while reindexing is still true must NOT stop polling.
+    expect(
+      nextReindexPollInterval({
+        ...base,
+        deadline: 10_000,
+        status: { reindexing: true, indexedPages: 478, totalPages: 478 },
+      }),
+    ).toBe(INTERVAL);
+  });
+
+  it('stops once the run is finished AND fully indexed', () => {
+    expect(
+      nextReindexPollInterval({
+        ...base,
+        deadline: 10_000,
+        status: { reindexing: false, indexedPages: 478, totalPages: 478 },
+      }),
+    ).toBe(false);
+  });
+
+  it('keeps polling within the deadline when not yet done and no active flag', () => {
+    // First poll right after enqueue, before the worker publishes progress.
+    expect(
+      nextReindexPollInterval({
+        ...base,
+        deadline: 10_000,
+        status: { reindexing: false, indexedPages: 0, totalPages: 478 },
+      }),
+    ).toBe(INTERVAL);
+  });
+
+  it('cap always wins: stops once past the deadline even if still reindexing', () => {
+    expect(
+      nextReindexPollInterval({
+        deadline: 1_000,
+        now: 2_000, // past the deadline
+        intervalMs: INTERVAL,
+        status: { reindexing: true, indexedPages: 200, totalPages: 478 },
+      }),
+    ).toBe(false);
+  });
+
+  it('stops on an empty workspace (0 of 0) once the run is finished', () => {
+    expect(
+      nextReindexPollInterval({
+        ...base,
+        deadline: 10_000,
+        status: { reindexing: false, indexedPages: 0, totalPages: 0 },
+      }),
+    ).toBe(false);
+  });
+});
+
+describe('isReindexComplete', () => {
+  it('false when no status yet', () => {
+    expect(isReindexComplete(undefined)).toBe(false);
+  });
+
+  it('false while a run is still active (even at indexed==total)', () => {
+    expect(
+      isReindexComplete({ reindexing: true, indexedPages: 478, totalPages: 478 }),
+    ).toBe(false);
+  });
+
+  it('false when finished but not yet fully indexed', () => {
+    expect(
+      isReindexComplete({ reindexing: false, indexedPages: 120, totalPages: 478 }),
+    ).toBe(false);
+  });
+
+  it('true once finished and fully indexed', () => {
+    expect(
+      isReindexComplete({ reindexing: false, indexedPages: 478, totalPages: 478 }),
+    ).toBe(true);
+  });
+});
+
+describe('isReindexButtonLoading', () => {
+  it('loads while the POST mutation is pending', () => {
+    expect(
+      isReindexButtonLoading({
+        mutationPending: true,
+        deadline: null,
+        status: false,
+      }),
+    ).toBe(true);
+  });
+
+  it('does NOT load post-cap: deadline nulled but reindexing left stale-true', () => {
+    // The key case: after the poll cap fires `reindexDeadline` is null while
+    // `settings.reindexing` can be a stale `true` from the last poll. Gating on
+    // the deadline keeps the spinner from sticking forever so the admin can
+    // restart.
+    expect(
+      isReindexButtonLoading({
+        mutationPending: false,
+        deadline: null,
+        status: true,
+      }),
+    ).toBe(false);
+  });
+
+  it('loads during an active run within the poll window', () => {
+    expect(
+      isReindexButtonLoading({
+        mutationPending: false,
+        deadline: 10_000,
+        status: true,
+      }),
+    ).toBe(true);
+  });
+
+  it('does not load once the run finished while still polling', () => {
+    expect(
+      isReindexButtonLoading({
+        mutationPending: false,
+        deadline: 10_000,
+        status: false,
+      }),
+    ).toBe(false);
+  });
+});

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

@@ -37,6 +37,7 @@ import {
 } from "@/features/workspace/queries/ai-settings-query.ts";
 import {
   AiTestCapability,
+  IAiSettings,
   IAiSettingsUpdate,
   SttApiStyle,
   ChatApiStyle,
@@ -169,6 +170,73 @@ export function resolveKeyField(
   return { set: false };
 }
 
+// Subset of the status payload that drives the reindex poll decisions.
+type ReindexStatus = Pick<
+  IAiSettings,
+  "reindexing" | "indexedPages" | "totalPages"
+>;
+
+/**
+ * Decide the TanStack Query `refetchInterval` while a reindex may be running.
+ * Returns the poll interval (ms) to keep polling, or `false` to stop.
+ *
+ * Polls while the server reports an ACTIVE run (`reindexing === true`) OR we are
+ * still within the deadline window and not yet fully indexed. Stops once the run
+ * has finished AND everything is indexed (server cleared its progress record and
+ * fell back to the DB coverage count), or the deadline cap is hit — the cap
+ * always wins so a stuck/never-clearing progress record can't poll forever.
+ */
+export function nextReindexPollInterval(args: {
+  deadline: number | null;
+  now: number;
+  intervalMs: number;
+  status?: ReindexStatus;
+}): number | false {
+  const { deadline, now, intervalMs, status } = args;
+  if (deadline === null) return false;
+  // Cap always wins.
+  if (now > deadline) return false;
+  // Active run → keep polling even if the momentary counts already look full.
+  if (status?.reindexing) return intervalMs;
+  // Finished and fully indexed (incl. an empty workspace, 0 >= 0) → stop. Reuse
+  // isReindexComplete so the completeness check lives in exactly one place.
+  if (isReindexComplete(status)) return false;
+  // Within the deadline and not yet done → keep polling.
+  return intervalMs;
+}
+
+/**
+ * Whether the reindex poll deadline should be cleared: the server reports no
+ * active run AND the count is complete. The single source of truth for the
+ * "reindex finished" check — `nextReindexPollInterval` reuses it for its stop
+ * condition (sans the cap, which the effect handles via time).
+ */
+export function isReindexComplete(status?: ReindexStatus): boolean {
+  return (
+    !!status && !status.reindexing && status.indexedPages >= status.totalPages
+  );
+}
+
+/**
+ * Whether the reindex button should show its spinner (and stay disabled).
+ *
+ * Spins while the POST is in flight, and for the WHOLE background run while the
+ * server reports `reindexing === true`. The `deadline !== null` gate is the
+ * load-bearing part: once the 120s poll cap fires it nulls `reindexDeadline`
+ * and stops refetching, so `status` (settings?.reindexing) can be a stale
+ * `true` from the last poll. Without the gate the spinner would stick forever
+ * for a run that outlives the cap and block a restart; gating on the active
+ * poll window clears it so the admin can re-trigger.
+ */
+export function isReindexButtonLoading(args: {
+  mutationPending: boolean;
+  deadline: number | null;
+  status?: boolean;
+}): boolean {
+  const { mutationPending, deadline, status } = args;
+  return mutationPending || (deadline !== null && status === true);
+}
+
 // Translate the dot's tooltip label. Kept in one place so all three endpoint
 // cards share identical wording.
 function cardStatusLabel(status: CardStatus, t: (k: string) => string): string {
@@ -215,31 +283,34 @@ export default function AiProviderSettings() {
   // PRE-job counts immediately, so the only way the "Indexed X of Y" counter
   // visibly climbs is to keep polling the settings query while the job runs.
   // `reindexDeadline` is the timestamp until which we poll (set on reindex
-  // success); polling stops early once indexed === total. Bounded so a stuck
-  // job can never poll forever.
-  const REINDEX_POLL_INTERVAL = 3000; // ms between refetches while indexing
+  // success). Polling tracks the server's `reindexing` flag: it keeps going for
+  // the whole active run and stops promptly once the server reports the run is
+  // finished. Bounded by the cap so a stuck/never-clearing progress record can
+  // never poll forever.
+  const REINDEX_POLL_INTERVAL = 5000; // ms between refetches while indexing
   const REINDEX_POLL_CAP_MS = 120000; // ~2 min hard cap
   const [reindexDeadline, setReindexDeadline] = useState<number | null>(null);
 
   // Only admins may read the (masked) AI settings; the server enforces this too.
-  const { data: settings, isLoading } = useAiSettingsQuery(isAdmin, (query) => {
-    if (reindexDeadline === null) return false;
-    // Past the cap → stop polling (cleared via the effect below too).
-    if (Date.now() > reindexDeadline) return false;
-    const data = query.state.data;
-    // Stop once everything is indexed; otherwise keep polling.
-    if (data && data.indexedPages >= data.totalPages) return false;
-    return REINDEX_POLL_INTERVAL;
-  });
+  const { data: settings, isLoading } = useAiSettingsQuery(isAdmin, (query) =>
+    nextReindexPollInterval({
+      deadline: reindexDeadline,
+      now: Date.now(),
+      intervalMs: REINDEX_POLL_INTERVAL,
+      status: query.state.data,
+    }),
+  );
 
-  // Stop polling once the work is done or the cap is reached. Also clears on
+  // Stop polling once the run is finished or the cap is reached. Also clears on
   // unmount because the deadline state goes away with the component.
   useEffect(() => {
     if (reindexDeadline === null) return;
-    // "Done" matches the refetchInterval stop condition (indexed >= total),
-    // including an empty workspace (0 >= 0), so the deadline clears promptly
-    // instead of waiting out the cap.
-    if (settings && settings.indexedPages >= settings.totalPages) {
+    // "Done" matches the refetchInterval stop condition: the server reports no
+    // active run AND the count is complete (indexed >= total, incl. an empty
+    // workspace 0 >= 0), so the deadline clears promptly instead of waiting out
+    // the cap. While `reindexing` is still true we keep the deadline so polling
+    // continues for the whole run.
+    if (isReindexComplete(settings)) {
       setReindexDeadline(null);
       return;
     }
@@ -1031,7 +1102,17 @@ export default function AiProviderSettings() {
             <Button
               variant="subtle"
               size="compact-sm"
-              loading={reindexMutation.isPending}
+              // Spin for the WHOLE run: the POST resolves immediately, but the
+              // background job keeps running, so also stay loading while the
+              // server reports `reindexing` (this also blocks a redundant
+              // re-trigger mid-run; the server de-dupes regardless). The
+              // deadline gate (and why it matters post-cap) lives in
+              // `isReindexButtonLoading`, which is unit-tested.
+              loading={isReindexButtonLoading({
+                mutationPending: reindexMutation.isPending,
+                deadline: reindexDeadline,
+                status: settings?.reindexing,
+              })}
               onClick={() =>
                 reindexMutation.mutate(undefined, {
                   // Begin bounded polling so the counter climbs as the async

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

@@ -23,8 +23,12 @@ export function useAiSettingsQuery(
   enabled: boolean = true,
   // While reindexing runs as an async background job, the counter only climbs
   // if the client keeps refetching. The component passes a refetchInterval
-  // function that polls until indexed === total or a bounded deadline, then
-  // returns false to stop. See AiProviderSettings.
+  // function (`nextReindexPollInterval`) that keeps polling while the server
+  // reports an active run (reindexing === true) OR we are still within the
+  // bounded deadline and not yet fully indexed; it returns false to stop only
+  // once the run has finished AND indexed >= total, or the deadline cap is hit
+  // (the cap always wins). Note: a transient indexed === total during an active
+  // run does NOT stop polling. See AiProviderSettings.
   refetchInterval?:
     | number
     | false

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

@@ -48,6 +48,9 @@ export interface IAiSettings {
   // RAG indexing coverage (pages indexed for semantic search).
   indexedPages: number;
   totalPages: number;
+  // True while a full workspace reindex is actively running; the counts above
+  // then reflect the live run progress (done climbs 0 -> total).
+  reindexing?: boolean;
 }
 
 // Update payload. Key semantics (same for `apiKey` and `embeddingApiKey`):

apps/client/src/main.tsx

@@ -11,7 +11,8 @@ import { MantineProvider } from "@mantine/core";
 import { BrowserRouter } from "react-router-dom";
 import { ModalsProvider } from "@mantine/modals";
 import { Notifications } from "@mantine/notifications";
-import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { QueryClient, onlineManager } from "@tanstack/react-query";
+import { PersistQueryClientProvider } from "@tanstack/react-query-persist-client";
 import { HelmetProvider } from "react-helmet-async";
 import "./i18n";
 import { PostHogProvider } from "posthog-js/react";
@@ -21,6 +22,13 @@ import {
   isCloud,
   isPostHogEnabled,
 } from "@/lib/config.ts";
+import {
+  queryPersister,
+  shouldDehydrateOfflineQuery,
+} from "@/features/offline/query-persister";
+import { registerOfflineMutationDefaults } from "@/features/offline/offline-mutations";
+import { PwaUpdatePrompt } from "@/pwa/pwa-update-prompt";
+import { isCapacitorNativePlatform } from "@/pwa/is-capacitor";
 import posthog from "posthog-js";
 
 export const queryClient = new QueryClient({
@@ -30,10 +38,30 @@ export const queryClient = new QueryClient({
       refetchOnWindowFocus: false,
       retry: false,
       staleTime: 5 * 60 * 1000,
+      // Keep cached read data around long enough to be persisted/restored for offline use.
+      gcTime: 1000 * 60 * 60 * 24,
     },
   },
 });
 
+// Register default mutationFns for the offline-relevant structural mutations so
+// a paused mutation restored from IndexedDB after an offline reload still has a
+// mutationFn and is replayed by resumePausedMutations() on reconnect (instead
+// of silently no-op'ing and dropping the offline create/move/comment). MUST run
+// before any resumePausedMutations() so rehydrated paused mutations have a fn.
+registerOfflineMutationDefaults(queryClient);
+
+// Seed TanStack Query's onlineManager from the REAL connectivity state at boot.
+// It defaults to `online: true` and only flips on window online/offline events,
+// so a tab that COLD-BOOTS offline would wrongly believe it is online: paused
+// mutations restored from IndexedDB would never get a later offline->online
+// transition to trigger their replay, and the offline UI affordances could not
+// tell they are offline. Seeding here makes the first real `online` event a true
+// transition that auto-resumes the rehydrated paused mutations (#120 data loss).
+if (typeof navigator !== "undefined" && "onLine" in navigator) {
+  onlineManager.setOnline(navigator.onLine);
+}
+
 if (isCloud() && isPostHogEnabled) {
   posthog.init(getPostHogKey(), {
     api_host: getPostHogHost(),
@@ -50,15 +78,44 @@ root.render(
   <BrowserRouter>
     <MantineProvider theme={theme} cssVariablesResolver={mantineCssResolver}>
       <ModalsProvider>
-        <QueryClientProvider client={queryClient}>
+        <PersistQueryClientProvider
+          client={queryClient}
+          persistOptions={{
+            persister: queryPersister,
+            maxAge: 1000 * 60 * 60 * 24,
+            buster: APP_VERSION,
+            dehydrateOptions: {
+              shouldDehydrateQuery: shouldDehydrateOfflineQuery,
+            },
+          }}
+          // After the persister finishes rehydrating, replay any paused
+          // mutations restored from IndexedDB. If we are back online this fires
+          // them immediately; if still offline they stay paused and TanStack's
+          // onlineManager auto-resumes them on the next online transition (which
+          // is now a true transition thanks to the onlineManager seeding above).
+          // Without this, a paused mutation persisted while offline and then
+          // reloaded would never resume and the user's work would be lost (#120).
+          onSuccess={() => {
+            queryClient.resumePausedMutations();
+          }}
+        >
           <Notifications position="bottom-center" limit={3} zIndex={10000} />
+          {/* Skip SW registration inside the Capacitor native WebView — the
+              native shell serves assets itself; a browser SW would conflict. */}
+          {!isCapacitorNativePlatform() && <PwaUpdatePrompt />}
           <HelmetProvider>
             <PostHogProvider client={posthog}>
               <App />
             </PostHogProvider>
           </HelmetProvider>
-        </QueryClientProvider>
+        </PersistQueryClientProvider>
       </ModalsProvider>
     </MantineProvider>
   </BrowserRouter>,
 );
+
+// Service worker registration is owned by <PwaUpdatePrompt /> above (via
+// vite-plugin-pwa's useRegisterSW: Workbox precache + prompt-based updates,
+// and skipped inside the Capacitor native WebView). The earlier hand-written
+// /sw.js registration from the mobile bootstrap was removed here to avoid a
+// double registration / competing service worker.

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

@@ -9,6 +9,7 @@ import { useGetSpaceBySlugQuery } from "@/features/space/queries/space-query.ts"
 import { useTranslation } from "react-i18next";
 import React from "react";
 import { EmptyState } from "@/components/ui/empty-state.tsx";
+import { OfflineFallback } from "@/features/offline/offline-fallback.tsx";
 import { IconAlertTriangle, IconFileOff } from "@tabler/icons-react";
 import { Button } from "@mantine/core";
 import { Link } from "react-router-dom";
@@ -62,7 +63,19 @@ function PageContent({ pageSlug }: { pageSlug: string | undefined }) {
   }
 
   if (isError || !page) {
-    if ([401, 403, 404].includes(error?.["status"])) {
+    // An offline fetch of a page that was never saved for offline use yields a
+    // network error with NO HTTP status (status is undefined), which would
+    // otherwise fall through to the generic "Error fetching page data." state.
+    // When we are offline (or the failure is a network error with no status),
+    // show the dedicated "You're offline — this page isn't saved for offline"
+    // fallback instead, so the user understands why the page won't load.
+    const httpStatus = error?.["status"];
+    const isOffline =
+      typeof navigator !== "undefined" && navigator.onLine === false;
+    if (isOffline || (isError && httpStatus == null)) {
+      return <OfflineFallback />;
+    }
+    if ([401, 403, 404].includes(httpStatus)) {
       return (
         <EmptyState
           icon={IconFileOff}

apps/client/src/pwa/is-capacitor.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect, afterEach } from "vitest";
+import { isCapacitorNativePlatform } from "./is-capacitor";
+
+describe("isCapacitorNativePlatform", () => {
+  afterEach(() => {
+    // Keep tests isolated from each other and from the rest of the suite.
+    delete (globalThis as any).Capacitor;
+  });
+
+  it("returns false when Capacitor is undefined", () => {
+    expect(isCapacitorNativePlatform()).toBe(false);
+  });
+
+  it("uses isNativePlatform() when it is a function", () => {
+    (globalThis as any).Capacitor = { isNativePlatform: () => true };
+    expect(isCapacitorNativePlatform()).toBe(true);
+
+    (globalThis as any).Capacitor = { isNativePlatform: () => false };
+    expect(isCapacitorNativePlatform()).toBe(false);
+  });
+
+  it("falls back to the boolean property when isNativePlatform is not a function", () => {
+    (globalThis as any).Capacitor = { isNativePlatform: true };
+    expect(isCapacitorNativePlatform()).toBe(true);
+
+    (globalThis as any).Capacitor = { isNativePlatform: false };
+    expect(isCapacitorNativePlatform()).toBe(false);
+  });
+
+  it("returns false when reading Capacitor throws (try/catch)", () => {
+    Object.defineProperty(globalThis, "Capacitor", {
+      configurable: true,
+      get() {
+        throw new Error("boom");
+      },
+    });
+    expect(isCapacitorNativePlatform()).toBe(false);
+  });
+});

apps/client/src/pwa/is-capacitor.ts

@@ -0,0 +1,23 @@
+/**
+ * Detects whether the client is running inside a Capacitor native WebView
+ * (native iOS/Android shell from the feature/mobile-app-bootstrap branch).
+ *
+ * This is a pure runtime check against the global `Capacitor` object that the
+ * native bridge injects — no `@capacitor/*` dependency is added. On the plain
+ * browser / installed-PWA path `window.Capacitor` is undefined, so this returns
+ * false and the Workbox service worker registers normally.
+ *
+ * Inside the native WebView the SW must NOT register: it would layer a redundant
+ * (and conflicting) cache over Capacitor's own asset serving and interfere with
+ * the native auth/CORS flow.
+ */
+export function isCapacitorNativePlatform(): boolean {
+  try {
+    const cap = (globalThis as any)?.Capacitor;
+    return !!(cap && typeof cap.isNativePlatform === "function"
+      ? cap.isNativePlatform()
+      : cap?.isNativePlatform);
+  } catch {
+    return false;
+  }
+}

apps/client/src/pwa/pwa-update-prompt.tsx

@@ -0,0 +1,59 @@
+import { useEffect } from "react";
+import { Button } from "@mantine/core";
+import { notifications } from "@mantine/notifications";
+import { useTranslation } from "react-i18next";
+import { useRegisterSW } from "virtual:pwa-register/react";
+
+// Stable notification id so we can show/hide a single update prompt.
+const UPDATE_NOTIFICATION_ID = "pwa-update-available";
+
+/**
+ * Listens for a waiting service worker and surfaces a Mantine notification
+ * prompting the user to reload into the new version.
+ *
+ * Must be mounted inside the Mantine provider subtree (Notifications must be
+ * available). Renders nothing itself.
+ */
+export function PwaUpdatePrompt() {
+  const { t } = useTranslation();
+
+  const {
+    needRefresh: [needRefresh],
+    updateServiceWorker,
+  } = useRegisterSW({
+    onRegisterError(error) {
+      // Best-effort: a failed registration must not break the app.
+      console.error("Service worker registration error:", error);
+    },
+  });
+
+  useEffect(() => {
+    if (!needRefresh) return;
+
+    notifications.show({
+      id: UPDATE_NOTIFICATION_ID,
+      title: t("Update available"),
+      message: (
+        <Button
+          size="xs"
+          variant="light"
+          mt="xs"
+          onClick={() => updateServiceWorker(true)}
+        >
+          {t("Reload")}
+        </Button>
+      ),
+      autoClose: false,
+      withCloseButton: true,
+    });
+
+    // Hide the notification when the prompt is no longer needed / on cleanup.
+    return () => {
+      notifications.hide(UPDATE_NOTIFICATION_ID);
+    };
+  }, [needRefresh, t, updateServiceWorker]);
+
+  return null;
+}
+
+export default PwaUpdatePrompt;

apps/client/src/pwa/sw-strategy.test.ts

@@ -0,0 +1,32 @@
+import { describe, it, expect } from "vitest";
+import { isApiPath, isCollabOrSocketPath } from "./sw-strategy";
+
+describe("isApiPath", () => {
+  it("matches the /api segment and its subtree", () => {
+    expect(isApiPath("/api")).toBe(true);
+    expect(isApiPath("/api/")).toBe(true);
+    expect(isApiPath("/api/pages")).toBe(true);
+  });
+
+  it("does not over-match sibling paths", () => {
+    expect(isApiPath("/apidocs")).toBe(false);
+    expect(isApiPath("/apixyz")).toBe(false);
+    expect(isApiPath("/")).toBe(false);
+    expect(isApiPath("/pages")).toBe(false);
+  });
+});
+
+describe("isCollabOrSocketPath", () => {
+  it("matches the /collab and /socket.io segments and their subtrees", () => {
+    expect(isCollabOrSocketPath("/collab")).toBe(true);
+    expect(isCollabOrSocketPath("/collab/x")).toBe(true);
+    expect(isCollabOrSocketPath("/socket.io")).toBe(true);
+    expect(isCollabOrSocketPath("/socket.io/abc")).toBe(true);
+  });
+
+  it("does not over-match sibling paths", () => {
+    expect(isCollabOrSocketPath("/collaborators")).toBe(false);
+    expect(isCollabOrSocketPath("/collabx")).toBe(false);
+    expect(isCollabOrSocketPath("/socket.iox")).toBe(false);
+  });
+});

apps/client/src/pwa/sw-strategy.ts

@@ -0,0 +1,32 @@
+/**
+ * Canonical service-worker routing predicates.
+ *
+ * IMPORTANT: With vite-plugin-pwa using Workbox `generateSW`, the
+ * `runtimeCaching[].urlPattern` functions are serialized standalone into the
+ * generated service worker and CANNOT reference imported symbols. The matching
+ * logic is therefore duplicated as inline regex literals in
+ * apps/client/vite.config.ts. This module is the testable source of truth, and
+ * the two MUST be kept in sync. This duplication is intentional and is the
+ * documented Workbox limitation.
+ *
+ * Matching is anchored to a path SEGMENT boundary (`^/<seg>(/|$)`) so that
+ * sibling paths like `/apidocs`, `/collaborators`, `/socket.iox` are NOT
+ * wrongly treated as API/realtime traffic.
+ */
+
+/**
+ * True when `pathname` is the `/api` segment or anything beneath it.
+ * `/api` and `/api/...` -> true; `/apidocs`, `/apixyz` -> false.
+ */
+export function isApiPath(pathname: string): boolean {
+  return /^\/api(\/|$)/.test(pathname);
+}
+
+/**
+ * True when `pathname` is the `/collab` or `/socket.io` segment (or beneath it).
+ * `/collab`, `/collab/x`, `/socket.io`, `/socket.io/abc` -> true;
+ * `/collaborators`, `/collabx`, `/socket.iox` -> false.
+ */
+export function isCollabOrSocketPath(pathname: string): boolean {
+  return /^\/(collab|socket\.io)(\/|$)/.test(pathname);
+}

apps/client/src/vite-env.d.ts

@@ -1,2 +1,4 @@
 /// <reference types="vite/client" />
+/// <reference types="vite-plugin-pwa/react" />
+/// <reference types="vite-plugin-pwa/info" />
 declare const APP_VERSION: string

apps/client/vite.config.ts

@@ -1,5 +1,6 @@
 import { defineConfig, loadEnv } from "vite";
 import react from "@vitejs/plugin-react";
+import { VitePWA } from "vite-plugin-pwa";
 import * as path from "path";
 import { execSync } from "node:child_process";
 
@@ -53,7 +54,55 @@ export default defineConfig(({ mode }) => {
       },
       APP_VERSION: JSON.stringify(resolveAppVersion(envPath)),
     },
-    plugins: [react()],
+    plugins: [
+      react(),
+      VitePWA({
+        registerType: "prompt",
+        injectRegister: null,
+        strategies: "generateSW",
+        manifest: false,
+        workbox: {
+          globPatterns: ["**/*.{js,css,html,svg,png,ico,woff2,json}"],
+          navigateFallback: "index.html",
+          // Segment-anchored (`^/<seg>(/|$)`) so navigation requests to these
+          // segments are consistently excluded from the SPA fallback, mirroring
+          // the runtimeCaching urlPattern regexes below.
+          //
+          // `/share`, `/mcp`, `/l`, and `/robots.txt` mirror the server
+          // static-serve exclude list (apps/server/src/main.ts setGlobalPrefix
+          // `exclude`): robots.txt, the SEO/OG/analytics-injected public share
+          // HTML, the embedded MCP endpoint, and the `l/:alias` vanity short-link
+          // (a server 302 to a share page) are served by server controllers, so
+          // the SW must never shadow them with the precached index.html app shell.
+          // For `/l/:alias` the client router has NO matching route, so serving
+          // the app shell would dead-end on Error404 and break the public link;
+          // it must reach the server to perform the redirect.
+          navigateFallbackDenylist: [
+            /^\/api(\/|$)/,
+            /^\/collab(\/|$)/,
+            /^\/socket\.io(\/|$)/,
+            /^\/share(\/|$)/,
+            /^\/mcp(\/|$)/,
+            /^\/l(\/|$)/,
+            /^\/robots\.txt$/,
+          ],
+          cleanupOutdatedCaches: true,
+          clientsClaim: true,
+          // The urlPattern regexes below mirror apps/client/src/pwa/sw-strategy.ts
+          // and MUST be kept in sync with it. Workbox `generateSW` serializes these
+          // functions standalone into the generated service worker, so they cannot
+          // import the module — the matching logic is intentionally duplicated as
+          // self-contained inline regex literals anchored to a path segment boundary.
+          runtimeCaching: [
+            { urlPattern: ({ url }) => /^\/(collab|socket\.io)(\/|$)/.test(url.pathname), handler: "NetworkOnly" },
+            // All /api stays network-only; offline reads come from the persisted
+            // React Query cache (IndexedDB) + y-indexeddb, not the SW HTTP cache.
+            { urlPattern: ({ url }) => /^\/api(\/|$)/.test(url.pathname), handler: "NetworkOnly" },
+          ],
+        },
+        devOptions: { enabled: false },
+      }),
+    ],
     build: {
       rolldownOptions: {
         output: {

apps/server/package.json

@@ -64,6 +64,7 @@
     "@nestjs/platform-fastify": "^11.1.19",
     "@nestjs/platform-socket.io": "^11.1.19",
     "@nestjs/schedule": "^6.1.3",
+    "@nestjs/swagger": "^11.2.0",
     "@nestjs/terminus": "^11.1.1",
     "@nestjs/throttler": "^6.5.0",
     "@nestjs/websockets": "^11.1.19",

apps/server/src/collaboration/collaboration.gateway.ts

@@ -24,7 +24,10 @@ import { CollabWsAdapter } from './adapter/collab-ws.adapter';
 import {
   CollaborationHandler,
   CollabEventHandlers,
+  writeTitleFragment,
 } from './collaboration.handler';
+import { User } from '@docmost/db/types/entity.types';
+import * as Y from 'yjs';
 
 @Injectable()
 export class CollaborationGateway {
@@ -155,6 +158,70 @@ export class CollaborationGateway {
     return this.hocuspocus.openDirectConnection(documentName, context);
   }
 
+  /**
+   * Write a new page title INTO the page's Yjs 'title' fragment, Redis-INDEPENDENT.
+   *
+   * Unlike the Redis-routed `handleYjsEvent` path — which routes through
+   * `redisSync?.handleEvent` and SILENTLY no-ops when Redis is disabled
+   * (COLLAB_DISABLE_REDIS=true → redisSync === null) — this goes straight
+   * through the local Hocuspocus `openDirectConnection`. The title sync
+   * therefore works in BOTH single-process (no Redis) and Redis-clustered
+   * deployments.
+   *
+   * openDirectConnection loads the doc from persistence when no editor is
+   * connected, so this works whether or not an editor is currently open: the
+   * clear+reseed lands on the loaded doc and is persisted by onStoreDocument.
+   *
+   * Provenance: when the caller is the agent, the actor/aiChatId are threaded
+   * into the connection `context` so onStoreDocument sees `context.actor ===
+   * 'agent'` for the resulting title store (mirrors the body/REST path). The
+   * resulting title store is usually a no-op anyway — PageService already wrote
+   * the same title to the page.title column, so onStoreDocument's
+   * `titleText !== page.title` guard skips the column write — but we wire the
+   * context for correctness regardless.
+   */
+  async writePageTitle(
+    pageId: string,
+    title: string,
+    context?: { user?: User; actor?: string; aiChatId?: string },
+  ): Promise<void> {
+    const documentName = `page.${pageId}`;
+    const connection = await this.hocuspocus.openDirectConnection(
+      documentName,
+      context ?? {},
+    );
+    try {
+      // Write the new title into the in-memory 'title' fragment AND capture the
+      // resulting full doc state so we can persist it directly below.
+      let ydocState: Buffer | null = null;
+      await connection.transact((doc) => {
+        writeTitleFragment(doc, title);
+        ydocState = Buffer.from(Y.encodeStateAsUpdate(doc));
+      });
+
+      // F1 (variant C): persist the 'title' fragment to `page.ydoc` DIRECTLY,
+      // bypassing onStoreDocument. PageService.update already wrote the new title
+      // to the page.title COLUMN before calling this, so onStoreDocument's no-op
+      // fast-path (titleText === column) would NOT persist the in-memory fragment
+      // on disconnect — leaving the stored ydoc with the OLD title, which a later
+      // body edit would then revert the column back to. Writing the ydoc here
+      // makes BOTH column and persisted fragment consistent (NEW = NEW).
+      //
+      // Safe with or without a live editor: the write is idempotent and carries
+      // no tree snapshot (no double broadcast); when an editor is connected, the
+      // normal onStoreDocument flow still persists the (superset) state later and
+      // the live clients receive the title change through the transact above.
+      if (ydocState) {
+        await this.persistenceExtension.persistTitleFragmentYdoc(
+          pageId,
+          ydocState,
+        );
+      }
+    } finally {
+      await connection.disconnect();
+    }
+  }
+
   /*
    *Can be used before calling openDirectConnection directly
    */

apps/server/src/collaboration/collaboration.handler.spec.ts

@@ -0,0 +1,155 @@
+import * as Y from 'yjs';
+import { TiptapTransformer } from '@hocuspocus/transformer';
+import { writeTitleFragment } from './collaboration.handler';
+import { CollaborationGateway } from './collaboration.gateway';
+import {
+  buildTitleSeedYdoc,
+  jsonToText,
+  tiptapExtensions,
+} from './collaboration.util';
+
+// Read the plain text held in the doc's 'title' XmlFragment, the same way
+// PersistenceExtension.onStoreDocument extracts it before writing page.title.
+const readTitleText = (doc: Y.Doc): string => {
+  const titleJson = TiptapTransformer.fromYdoc(doc, 'title');
+  return titleJson ? jsonToText(titleJson).trim() : '';
+};
+
+describe('writeTitleFragment — the clear+seed title write (Bug 1)', () => {
+  it('replaces an OLD title fragment with EXACTLY the new title (no duplication)', () => {
+    // Seed the doc's 'title' fragment with an OLD title, like a real page.
+    const doc = new Y.Doc();
+    Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Old Title')));
+    expect(readTitleText(doc)).toBe('Old Title');
+
+    writeTitleFragment(doc, 'New Title');
+
+    // The fragment must contain EXACTLY the new title — not "Old TitleNew Title"
+    // (append) or "New TitleNew Title" (duplication). A single heading node.
+    expect(readTitleText(doc)).toBe('New Title');
+
+    const titleJson = TiptapTransformer.fromYdoc(doc, 'title') as any;
+    expect(titleJson.content).toHaveLength(1);
+    expect(titleJson.content[0].type).toBe('heading');
+  });
+
+  it('seeds the title fragment when it started empty', () => {
+    const doc = new Y.Doc();
+    // Force the 'title' fragment to exist but be empty.
+    doc.getXmlFragment('title');
+    expect(readTitleText(doc)).toBe('');
+
+    writeTitleFragment(doc, 'First Title');
+
+    expect(readTitleText(doc)).toBe('First Title');
+  });
+
+  it('does not corrupt the body when rewriting the title', () => {
+    // A doc with both a body and an old title; the body must survive untouched.
+    const doc = new Y.Doc();
+    const bodyDoc = TiptapTransformer.toYdoc(
+      {
+        type: 'doc',
+        content: [
+          { type: 'paragraph', content: [{ type: 'text', text: 'body text' }] },
+        ],
+      },
+      'default',
+      tiptapExtensions,
+    );
+    Y.applyUpdate(doc, Y.encodeStateAsUpdate(bodyDoc));
+    Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Old')));
+
+    writeTitleFragment(doc, 'New');
+
+    expect(readTitleText(doc)).toBe('New');
+    const bodyJson = TiptapTransformer.fromYdoc(doc, 'default');
+    expect(jsonToText(bodyJson)).toContain('body text');
+  });
+});
+
+describe('CollaborationGateway.writePageTitle — Redis-independent path', () => {
+  // Build a gateway with only its hocuspocus.openDirectConnection stubbed; the
+  // method must drive the clear+seed through that direct connection (NOT through
+  // redisSync), so the title write survives COLLAB_DISABLE_REDIS.
+  const makeGateway = (doc: Y.Doc) => {
+    const disconnect = jest.fn().mockResolvedValue(undefined);
+    const transact = jest.fn(async (fn: (d: Y.Doc) => void) => {
+      fn(doc);
+    });
+    const openDirectConnection = jest
+      .fn()
+      .mockResolvedValue({ transact, disconnect });
+
+    const gateway = Object.create(CollaborationGateway.prototype);
+    // redisSync is intentionally null — this is the no-Redis scenario.
+    gateway.redisSync = null;
+    gateway.hocuspocus = { openDirectConnection } as any;
+    // F1 (variant C): writePageTitle persists the 'title' fragment directly so a
+    // later body edit can't revert the rename (see title-rename-durability.spec).
+    const persistTitleFragmentYdoc = jest.fn().mockResolvedValue(undefined);
+    gateway.persistenceExtension = { persistTitleFragmentYdoc } as any;
+
+    return {
+      gateway,
+      openDirectConnection,
+      transact,
+      disconnect,
+      persistTitleFragmentYdoc,
+    };
+  };
+
+  it('writes the new title via openDirectConnection and disconnects', async () => {
+    const doc = new Y.Doc();
+    Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Old Title')));
+
+    const { gateway, openDirectConnection, disconnect, persistTitleFragmentYdoc } =
+      makeGateway(doc);
+
+    await gateway.writePageTitle('page-1', 'New Title', { user: { id: 'u1' } });
+
+    expect(openDirectConnection).toHaveBeenCalledWith(
+      'page.page-1',
+      expect.objectContaining({ user: { id: 'u1' } }),
+    );
+    expect(readTitleText(doc)).toBe('New Title');
+    // The renamed fragment is persisted directly to page.ydoc (F1 variant C).
+    expect(persistTitleFragmentYdoc).toHaveBeenCalledWith(
+      'page-1',
+      expect.any(Buffer),
+    );
+    expect(disconnect).toHaveBeenCalledTimes(1);
+  });
+
+  it('threads agent provenance into the connection context', async () => {
+    const doc = new Y.Doc();
+    const { gateway, openDirectConnection } = makeGateway(doc);
+
+    await gateway.writePageTitle('page-1', 'Agent Title', {
+      user: { id: 'u1' },
+      actor: 'agent',
+      aiChatId: 'chat-1',
+    });
+
+    expect(openDirectConnection).toHaveBeenCalledWith(
+      'page.page-1',
+      expect.objectContaining({ actor: 'agent', aiChatId: 'chat-1' }),
+    );
+  });
+
+  it('disconnects even when the transaction throws', async () => {
+    const disconnect = jest.fn().mockResolvedValue(undefined);
+    const openDirectConnection = jest.fn().mockResolvedValue({
+      transact: jest.fn().mockRejectedValue(new Error('boom')),
+      disconnect,
+    });
+    const gateway = Object.create(CollaborationGateway.prototype);
+    gateway.redisSync = null;
+    gateway.hocuspocus = { openDirectConnection } as any;
+
+    await expect(
+      gateway.writePageTitle('page-1', 'X', {}),
+    ).rejects.toThrow('boom');
+    expect(disconnect).toHaveBeenCalledTimes(1);
+  });
+});

apps/server/src/collaboration/collaboration.handler.ts

@@ -2,6 +2,7 @@ import { Injectable, Logger } from '@nestjs/common';
 import { Hocuspocus, Document } from '@hocuspocus/server';
 import { TiptapTransformer } from '@hocuspocus/transformer';
 import {
+  buildTitleSeedYdoc,
   prosemirrorNodeToYElement,
   tiptapExtensions,
 } from './collaboration.util';
@@ -13,6 +14,35 @@ export type CollabEventHandlers = ReturnType<
   CollaborationHandler['getHandlers']
 >;
 
+/**
+ * Clear+reseed the 'title' XmlFragment of `doc` so it holds EXACTLY `title`.
+ *
+ * Used by the gateway's direct `writePageTitle` method to write a new page
+ * title INTO the page's Yjs 'title' fragment. The title lives in the same
+ * Y.Doc as the body; onStoreDocument extracts it on every save, so a REST/MCP
+ * rename that only updated the page.title DB column would be reverted on the
+ * next collaborative save unless the Yjs 'title' fragment is kept in sync.
+ * The whole fragment is replaced (no merge/append),
+ * mirroring the 'replace' body path: the new title fully supersedes the old.
+ *
+ * DELIBERATE TRADE-OFF: because this does a FULL clear+replace of the 'title'
+ * fragment, a REST/MCP rename arriving while a user is actively editing the
+ * title in an open editor WILL overwrite that in-progress edit. This is
+ * acceptable — the title is a short, rarely-concurrently-edited field — and is
+ * preferable to leaving a stale Yjs title that onStoreDocument would revert the
+ * DB column to on the next save.
+ */
+export function writeTitleFragment(doc: Y.Doc, title: string): void {
+  const titleFragment = doc.getXmlFragment('title');
+
+  if (titleFragment.length > 0) {
+    titleFragment.delete(0, titleFragment.length);
+  }
+
+  const newTitleDoc = buildTitleSeedYdoc(title);
+  Y.applyUpdate(doc, Y.encodeStateAsUpdate(newTitleDoc));
+}
+
 @Injectable()
 export class CollaborationHandler {
   private readonly logger = new Logger(CollaborationHandler.name);

apps/server/src/collaboration/collaboration.util.spec.ts

@@ -1,9 +1,12 @@
 import * as Y from 'yjs';
+import { TiptapTransformer } from '@hocuspocus/transformer';
 import {
   getPageId,
   isEmptyParagraphDoc,
   jsonToNode,
   prosemirrorNodeToYElement,
+  buildTitleSeedYdoc,
+  jsonToText,
 } from './collaboration.util';
 import { Node } from '@tiptap/pm/model';
 
@@ -241,3 +244,43 @@ describe('prosemirrorNodeToYElement', () => {
     expect(element.get(1).get(0).toString()).toBe('two');
   });
 });
+
+describe('buildTitleSeedYdoc', () => {
+  it('builds a level-1 heading carrying the title text', () => {
+    const doc = buildTitleSeedYdoc('Hello World');
+    const json: any = TiptapTransformer.fromYdoc(doc, 'title');
+
+    const first = json.content?.[0];
+    expect(first.type).toBe('heading');
+    expect(first.attrs.level).toBe(1);
+    expect(jsonToText(json).trim()).toBe('Hello World');
+  });
+
+  it('produces a non-empty title fragment for a non-empty title', () => {
+    const doc = buildTitleSeedYdoc('Some Title');
+    expect(doc.get('title', Y.XmlFragment).length).toBeGreaterThan(0);
+  });
+
+  it('produces a heading with no text child for an empty title', () => {
+    const doc = buildTitleSeedYdoc('');
+    const json: any = TiptapTransformer.fromYdoc(doc, 'title');
+
+    const first = json.content?.[0];
+    expect(first.type).toBe('heading');
+    // No text content for an empty title.
+    expect(first.content ?? []).toHaveLength(0);
+    expect(jsonToText(json).trim()).toBe('');
+  });
+
+  it('round-trips a title through build -> extract -> build -> extract', () => {
+    const title = 'Round Trip Title';
+    const doc1 = buildTitleSeedYdoc(title);
+    const text1 = jsonToText(TiptapTransformer.fromYdoc(doc1, 'title')).trim();
+
+    const doc2 = buildTitleSeedYdoc(text1);
+    const text2 = jsonToText(TiptapTransformer.fromYdoc(doc2, 'title')).trim();
+
+    expect(text1).toBe(title);
+    expect(text2).toBe(text1);
+  });
+});

apps/server/src/collaboration/collaboration.util.ts

@@ -60,6 +60,7 @@ import { generateHTML, generateJSON } from '../common/helpers/prosemirror/html';
 import { Node, Schema } from '@tiptap/pm/model';
 import * as Y from 'yjs';
 import { Logger } from '@nestjs/common';
+import { TiptapTransformer } from '@hocuspocus/transformer';
 
 export const tiptapExtensions = [
   StarterKit.configure({
@@ -145,6 +146,34 @@ export function jsonToText(tiptapJson: JSONContent) {
   return generateText(tiptapJson, tiptapExtensions);
 }
 
+/**
+ * Build a standalone Y.Doc that holds ONLY the page title, in a dedicated Yjs
+ * fragment named exactly 'title' (the collaborative title-editor contract with
+ * the client). The ProseMirror shape is a doc with a single level-1 heading
+ * whose text is the title (empty title => heading with no text child).
+ *
+ * The encoded state of the returned doc can be merged into a body doc via
+ * `Y.applyUpdate(doc, Y.encodeStateAsUpdate(titleSeed))` to seed the title
+ * fragment for legacy pages. Seeding MUST be guarded by an emptiness check on
+ * the existing 'title' fragment to avoid the Yjs duplication trap.
+ */
+export function buildTitleSeedYdoc(title: string): Y.Doc {
+  return TiptapTransformer.toYdoc(
+    {
+      type: 'doc',
+      content: [
+        {
+          type: 'heading',
+          attrs: { level: 1 },
+          content: title ? [{ type: 'text', text: title }] : [],
+        },
+      ],
+    },
+    'title',
+    tiptapExtensions,
+  );
+}
+
 export function jsonToNode(tiptapJson: JSONContent) {
   const schema = getSchema(tiptapExtensions);
   try {

apps/server/src/collaboration/constants.ts

@@ -1,3 +1,9 @@
 export const HISTORY_INTERVAL = 5 * 60 * 1000;
 export const HISTORY_FAST_INTERVAL = 60 * 1000;
 export const HISTORY_FAST_THRESHOLD = 5 * 60 * 1000;
+
+// Redis pub/sub channel that bridges a PAGE_UPDATED tree snapshot (a title/icon
+// rename) from the standalone collab process to the API process, which is the
+// single broadcast authority. Imported by both halves of the bridge:
+// PageTreeBridgePublisher (collab process) and PageTreeBridgeSubscriber (API process).
+export const COLLAB_TREE_UPDATE_CHANNEL = 'collab:tree-update';

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

@@ -1,6 +1,7 @@
+import * as Y from 'yjs';
 import { TiptapTransformer } from '@hocuspocus/transformer';
 import { PersistenceExtension } from './persistence.extension';
-import { tiptapExtensions } from '../collaboration.util';
+import { buildTitleSeedYdoc, tiptapExtensions } from '../collaboration.util';
 
 /**
  * Integration test for `onStoreDocument`'s Approach-A boundary snapshot.
@@ -205,31 +206,278 @@ describe('PersistenceExtension.onStoreDocument — Approach-A boundary snapshot'
     expect(historyQueue.add).toHaveBeenCalledTimes(1);
   });
 
-  // #206 persist-6 — RED (it.failing): a momentarily-empty live Y.Doc must not
-  // overwrite non-empty persisted content. `onStoreDocument` empty-guards the
-  // LOAD path but not the STORE path, so today an empty doc (a client/agent
-  // glitch, a bad merge, an emptying transclusion) is written straight over the
-  // page and the content is wiped silently. A store-side empty-guard is a real
-  // behaviour change (a deliberate "select-all + delete" is also empty), so it
-  // is left UNFIXED pending a product decision; this documents the data-loss
-  // path and flips to a normal passing test the moment the guard lands.
-  it.failing(
-    'does NOT overwrite non-empty content with a momentarily-empty live doc (persist-6)',
-    async () => {
-      const emptyDoc = { type: 'doc', content: [{ type: 'paragraph' }] };
-      const document = ydocFor(emptyDoc);
-      pageRepo.findById.mockResolvedValue({
-        ...persistedHumanPage('IGNORED'),
-        content: doc('IMPORTANT RICH CONTENT'),
-      });
+  // #206 persist-6 / #248 — a momentarily-empty live Y.Doc must not overwrite
+  // non-empty persisted content. The store-side empty-guard blocks an empty doc
+  // (a client/agent glitch, a bad merge, an emptying transclusion) from wiping
+  // the page silently when NO intentional-clear signal is present.
+  it('does NOT overwrite non-empty content with a momentarily-empty live doc (persist-6)', async () => {
+    const emptyDoc = { type: 'doc', content: [{ type: 'paragraph' }] };
+    const document = ydocFor(emptyDoc);
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+    });
 
-      await ext.onStoreDocument(buildData(document, 'user') as any);
+    await ext.onStoreDocument(buildData(document, 'user') as any);
 
-      // Desired contract: the empty incoming doc is rejected and the rich page
-      // survives. Today updatePage is called with the empty content (data loss).
-      expect(pageRepo.updatePage).not.toHaveBeenCalled();
-    },
-  );
+    // The empty incoming doc is rejected and the rich page survives.
+    expect(pageRepo.updatePage).not.toHaveBeenCalled();
+  });
+
+  // #248 — an empty-over-empty store is allowed (nothing to lose); the guard
+  // only protects non-empty persisted content.
+  it('allows an empty store over already-empty content (#248)', async () => {
+    const liveEmptyDoc = { type: 'doc', content: [{ type: 'paragraph' }] };
+    const document = ydocFor(liveEmptyDoc);
+    // Stored content is empty per isEmptyParagraphDoc (paragraph with content:[])
+    // but NOT deep-equal to the normalized live doc, so the unchanged
+    // short-circuit is skipped and the empty-guard is genuinely reached.
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: { type: 'doc', content: [{ type: 'paragraph', content: [] }] },
+    });
+
+    await ext.onStoreDocument(buildData(document, 'user') as any);
+
+    expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+  });
+
+  // #251 — REAL-PATH regression test. The intentional-clear signal is set via
+  // the actual transport seam (ext.onStateless with the exact stateless payload
+  // the client's IntentionalClear extension sends), NOT a hand-injected
+  // context.intentionalClear poke. We then run the debounced store with an empty
+  // live doc over non-empty persisted content and assert the empty write goes
+  // through — i.e. the clear persists.
+  it('persists an intentional clear signalled via the real stateless transport (#251)', async () => {
+    const documentName = `page.${PAGE_ID}`;
+    const emptyDoc = { type: 'doc', content: [{ type: 'paragraph' }] };
+    const document = ydocFor(emptyDoc);
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+    });
+
+    // The client signalled a deliberate clear over the live connection.
+    await ext.onStateless({
+      connection: { readOnly: false } as any,
+      documentName,
+      document: document as any,
+      payload: JSON.stringify({ type: 'intentional-clear' }),
+    } as any);
+
+    await ext.onStoreDocument(buildData(document, 'user') as any);
+
+    // The empty doc was written (the clear persisted). The persisted content is
+    // the Y.Doc round-trip of the empty doc (attrs normalized), so compare
+    // against fromYdoc rather than the raw literal.
+    expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+    const expectedEmpty = TiptapTransformer.fromYdoc(document, 'default');
+    expect(pageRepo.updatePage.mock.calls[0][0].content).toEqual(expectedEmpty);
+  });
+
+  // #251 — retry correctness: a transient DB failure on the FIRST attempt must
+  // not silently drop the clear. The intentional-clear flag is consumed ONCE
+  // before the retry loop, so when attempt 1's updatePage throws (tx rolls back,
+  // but the in-memory flag delete cannot roll back) the retry on attempt 2 still
+  // sees the clear as allowed and writes the empty doc. On the pre-fix code
+  // (consumeIntentionalClear called INSIDE the loop) attempt 1 consumed the flag,
+  // attempt 2 re-read it as absent and the empty-guard BLOCKED the write — so
+  // updatePage would be called once and the clear would be lost. This test fails
+  // on that ordering and passes after the hoist.
+  it('persists an intentional clear even when the first store attempt fails transiently (#251)', async () => {
+    const documentName = `page.${PAGE_ID}`;
+    const emptyDoc = { type: 'doc', content: [{ type: 'paragraph' }] };
+    const document = ydocFor(emptyDoc);
+    // The page stays non-empty in the DB across both attempts (the rolled-back
+    // first attempt never changed it), exactly the failure scenario the WARNING
+    // describes.
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+    });
+
+    let attempts = 0;
+    pageRepo.updatePage.mockImplementation(async () => {
+      attempts += 1;
+      if (attempts === 1) throw new Error('deadlock detected'); // transient
+      callOrder.push('updatePage');
+    });
+
+    // The client signalled a deliberate clear over the live connection.
+    await ext.onStateless({
+      connection: { readOnly: false } as any,
+      documentName,
+      document: document as any,
+      payload: JSON.stringify({ type: 'intentional-clear' }),
+    } as any);
+
+    await ext.onStoreDocument(buildData(document, 'user') as any);
+
+    // First attempt failed and rolled back; the retry still honoured the clear
+    // and wrote the empty doc (the clear survived the retry).
+    expect(pageRepo.updatePage).toHaveBeenCalledTimes(2);
+    const expectedEmpty = TiptapTransformer.fromYdoc(document, 'default');
+    expect(pageRepo.updatePage.mock.calls[1][0].content).toEqual(expectedEmpty);
+  });
+
+  // #251 — the signal is single-use: it is consumed by the first empty store,
+  // so a SECOND accidental empty (no fresh signal) is still blocked.
+  it('consumes the intentional-clear signal once; a later empty is blocked (#251)', async () => {
+    const documentName = `page.${PAGE_ID}`;
+    const emptyDoc = { type: 'doc', content: [{ type: 'paragraph' }] };
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+    });
+
+    await ext.onStateless({
+      connection: { readOnly: false } as any,
+      documentName,
+      document: ydocFor(emptyDoc) as any,
+      payload: JSON.stringify({ type: 'intentional-clear' }),
+    } as any);
+
+    // First empty store consumes the signal and writes.
+    await ext.onStoreDocument(buildData(ydocFor(emptyDoc), 'user') as any);
+    expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+
+    // Re-arm findById to non-empty (as if content came back) and fire another
+    // empty store WITHOUT a new signal — the guard must block it.
+    pageRepo.updatePage.mockClear();
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+    });
+    await ext.onStoreDocument(buildData(ydocFor(emptyDoc), 'user') as any);
+    expect(pageRepo.updatePage).not.toHaveBeenCalled();
+  });
+
+  // #251 — a read-only connection cannot arm the clear, so its empty store is
+  // still blocked (defends the guard against a read-only spoof).
+  it('ignores an intentional-clear signal from a read-only connection (#251)', async () => {
+    const documentName = `page.${PAGE_ID}`;
+    const emptyDoc = { type: 'doc', content: [{ type: 'paragraph' }] };
+    const document = ydocFor(emptyDoc);
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+    });
+
+    await ext.onStateless({
+      connection: { readOnly: true } as any,
+      documentName,
+      document: document as any,
+      payload: JSON.stringify({ type: 'intentional-clear' }),
+    } as any);
+
+    await ext.onStoreDocument(buildData(document, 'user') as any);
+
+    expect(pageRepo.updatePage).not.toHaveBeenCalled();
+  });
+
+  // #251 — a non-empty store between the signal and the empty store drops the
+  // pending flag ("cleared then retyped" can't leave a usable signal behind).
+  it('drops a pending clear when a non-empty store intervenes (#251)', async () => {
+    const documentName = `page.${PAGE_ID}`;
+    const emptyDoc = { type: 'doc', content: [{ type: 'paragraph' }] };
+
+    await ext.onStateless({
+      connection: { readOnly: false } as any,
+      documentName,
+      document: ydocFor(emptyDoc) as any,
+      payload: JSON.stringify({ type: 'intentional-clear' }),
+    } as any);
+
+    // A non-empty store lands first → consumes/drops the stale flag.
+    pageRepo.findById.mockResolvedValue(persistedHumanPage('NEW HUMAN TEXT'));
+    await ext.onStoreDocument(
+      buildData(ydocFor(doc('NEW HUMAN TEXT')), 'user') as any,
+    );
+    pageRepo.updatePage.mockClear();
+
+    // Now an empty store with no fresh signal must be blocked.
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+    });
+    await ext.onStoreDocument(buildData(ydocFor(emptyDoc), 'user') as any);
+    expect(pageRepo.updatePage).not.toHaveBeenCalled();
+  });
+
+  // #248/#251 ⋈ title-change INTERSECTION — the empty-guard must dominate a
+  // simultaneous rename. The two guards merged by the rebase are exercised in
+  // isolation everywhere else: every empty-guard test sends a body with NO title
+  // fragment, and every title test sends a NON-empty body. This test hits their
+  // intersection: an empty body ('default') carrying a CHANGED, non-empty title
+  // fragment ('New Title' over an OLD 'Old Title') landing on non-empty persisted
+  // content, with NO intentional-clear. Because the body is empty,
+  // bodyChanged===true, so the store goes down the BODY path (not the title-only
+  // branch, which requires !bodyChanged) and reaches the empty-guard while
+  // titleChanged===true. The guard must block the WHOLE store: the rename rides on
+  // the same updatePage as the body, so persisting the title would also wipe the
+  // body. Nothing may be written — the rich content (and old title) survive.
+  it('blocks the whole store — empty body drops a simultaneous rename too (#248/#251 ⋈ title)', async () => {
+    // Empty body in the 'default' fragment...
+    const document = ydocFor({ type: 'doc', content: [{ type: 'paragraph' }] });
+    // ...plus a CHANGED, non-empty title fragment in the SAME Y.Doc.
+    Y.applyUpdate(document, Y.encodeStateAsUpdate(buildTitleSeedYdoc('New Title')));
+    (document as any).broadcastStateless =
+      (document as any).broadcastStateless || jest.fn();
+
+    // Persisted content is non-empty AND titled differently, so both
+    // bodyChanged and titleChanged are true when the store runs.
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+      title: 'Old Title',
+    });
+
+    // No intentional-clear signalled → the empty-guard blocks.
+    await ext.onStoreDocument(buildData(document, 'user') as any);
+
+    // Neither the body nor the new title is written; the rich content and the
+    // old title both survive. (Non-vacuity: if the guard let the rename through,
+    // updatePage would be called with title:'New Title' on the body path.)
+    expect(pageRepo.updatePage).not.toHaveBeenCalled();
+  });
+
+  // #248/#251 ⋈ title INTERSECTION, allowed side — a deliberate clear lets BOTH
+  // the empty body AND the simultaneous rename through. Same doc as above (empty
+  // body + changed 'New Title'), but the clear is armed first via the REAL
+  // stateless transport seam (exactly as the #251 tests do). The body path then
+  // persists once, and because titleChanged===true the same updatePage carries
+  // the new title — the rename rides along with the deliberate clear.
+  it('allows the empty body AND the rename when an intentional clear is signalled (#248/#251 ⋈ title)', async () => {
+    const documentName = `page.${PAGE_ID}`;
+    const document = ydocFor({ type: 'doc', content: [{ type: 'paragraph' }] });
+    Y.applyUpdate(document, Y.encodeStateAsUpdate(buildTitleSeedYdoc('New Title')));
+    (document as any).broadcastStateless =
+      (document as any).broadcastStateless || jest.fn();
+
+    pageRepo.findById.mockResolvedValue({
+      ...persistedHumanPage('IGNORED'),
+      content: doc('IMPORTANT RICH CONTENT'),
+      title: 'Old Title',
+    });
+
+    // The client signalled a deliberate clear over the live connection.
+    await ext.onStateless({
+      connection: { readOnly: false } as any,
+      documentName,
+      document: document as any,
+      payload: JSON.stringify({ type: 'intentional-clear' }),
+    } as any);
+
+    await ext.onStoreDocument(buildData(document, 'user') as any);
+
+    // The empty body was allowed and the rename rode along on the same write.
+    expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+    expect(pageRepo.updatePage.mock.calls[0][0].title).toBe('New Title');
+    // Pin that this went down the BODY path (not the title-only branch): the
+    // persisted content is the empty doc, i.e. the deliberate clear was written.
+    const expectedEmpty = TiptapTransformer.fromYdoc(document, 'default');
+    expect(pageRepo.updatePage.mock.calls[0][0].content).toEqual(expectedEmpty);
+  });
 
   // persist-1 — when every attempt fails the hook must NOT report a phantom
   // success: no "page.updated" badge broadcast and no history snapshot for

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

@@ -0,0 +1,483 @@
+import * as Y from 'yjs';
+import { TiptapTransformer } from '@hocuspocus/transformer';
+import { PersistenceExtension } from './persistence.extension';
+import { buildTitleSeedYdoc, tiptapExtensions } from '../collaboration.util';
+
+// Direct instantiation with stub deps, mirroring the auth/env unit specs.
+const bodyJson = {
+  type: 'doc',
+  content: [{ type: 'paragraph', content: [{ type: 'text', text: 'hello' }] }],
+};
+
+// Build a body Y.Doc with a known JSON, plus a monkey-patched broadcastStateless
+// (the real Hocuspocus Document supplies it; a bare Y.Doc does not).
+const buildDoc = () => {
+  const d: any = TiptapTransformer.toYdoc(bodyJson, 'default', tiptapExtensions);
+  d.broadcastStateless = jest.fn();
+  return d;
+};
+
+const cloneOut = (doc: any) =>
+  JSON.parse(JSON.stringify(TiptapTransformer.fromYdoc(doc, 'default')));
+
+const addTitleFragment = (doc: any, title: string) =>
+  Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc(title)));
+
+describe('PersistenceExtension', () => {
+  let pageRepo: any;
+  let pageHistoryRepo: any;
+  let trx: any;
+  let db: any;
+  let aiQueue: any;
+  let historyQueue: any;
+  let notificationQueue: any;
+  let collabHistory: any;
+  let transclusionService: any;
+  let ext: PersistenceExtension;
+
+  beforeEach(() => {
+    pageRepo = {
+      findById: jest.fn(),
+      updatePage: jest.fn().mockResolvedValue(undefined),
+    };
+    pageHistoryRepo = {
+      findPageLastHistory: jest.fn(),
+      saveHistory: jest.fn(),
+    };
+    trx = {};
+    db = { transaction: () => ({ execute: (fn: any) => fn(trx) }) };
+    aiQueue = { add: jest.fn().mockResolvedValue(undefined) };
+    historyQueue = { add: jest.fn().mockResolvedValue(undefined) };
+    notificationQueue = { add: jest.fn().mockResolvedValue(undefined) };
+    collabHistory = { addContributors: jest.fn().mockResolvedValue(undefined) };
+    transclusionService = {
+      syncPageTransclusions: jest.fn().mockResolvedValue(undefined),
+      syncPageReferences: jest.fn().mockResolvedValue(undefined),
+      syncPageTemplateReferences: jest.fn().mockResolvedValue(undefined),
+    };
+
+    ext = new PersistenceExtension(
+      pageRepo as any,
+      pageHistoryRepo as any,
+      db as any,
+      aiQueue as any,
+      historyQueue as any,
+      notificationQueue as any,
+      collabHistory as any,
+      transclusionService as any,
+    );
+  });
+
+  describe('seedTitleFragment', () => {
+    it('returns false for empty/whitespace/null titles', () => {
+      const doc = new Y.Doc();
+      expect((ext as any).seedTitleFragment(doc, '')).toBe(false);
+      expect((ext as any).seedTitleFragment(doc, '   ')).toBe(false);
+      expect((ext as any).seedTitleFragment(doc, null)).toBe(false);
+    });
+
+    it('does NOT re-seed an existing non-empty title fragment', () => {
+      const doc = new Y.Doc();
+      addTitleFragment(doc, 'Existing');
+
+      expect((ext as any).seedTitleFragment(doc, 'Other')).toBe(false);
+
+      const text = TiptapTransformer.fromYdoc(doc, 'title');
+      expect(JSON.stringify(text)).toContain('Existing');
+      expect(JSON.stringify(text)).not.toContain('Other');
+    });
+
+    it('seeds an empty fragment from a non-empty title and returns true', () => {
+      const doc = new Y.Doc();
+      expect((ext as any).seedTitleFragment(doc, 'Hello')).toBe(true);
+
+      const json: any = TiptapTransformer.fromYdoc(doc, 'title');
+      expect(JSON.stringify(json)).toContain('Hello');
+    });
+
+    it('returns false (defensive) when reading the fragment throws', () => {
+      const fakeDoc = {
+        get: () => {
+          throw new Error('boom');
+        },
+      };
+      expect((ext as any).seedTitleFragment(fakeDoc as any, 'X')).toBe(false);
+    });
+  });
+
+  describe('onStoreDocument', () => {
+    const basePage = (overrides: any) => ({
+      id: 'PAGE_ID',
+      slugId: 'slug',
+      spaceId: 'space',
+      parentPageId: null,
+      creatorId: 'creator',
+      contributorIds: ['creator'],
+      workspaceId: 'ws',
+      title: 'whatever',
+      content: null,
+      lastUpdatedSource: 'user',
+      createdAt: new Date().toISOString(),
+      ...overrides,
+    });
+
+    const context = { user: { id: 'u1', name: 'U', avatarUrl: null } };
+
+    it('no-op when neither body nor title changed', async () => {
+      const document = buildDoc();
+      const page = basePage({
+        content: cloneOut(document),
+        title: 'hello title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+      expect(document.broadcastStateless).not.toHaveBeenCalled();
+      expect(collabHistory.addContributors).not.toHaveBeenCalled();
+      expect(transclusionService.syncPageTransclusions).not.toHaveBeenCalled();
+      expect(aiQueue.add).not.toHaveBeenCalled();
+      expect(historyQueue.add).not.toHaveBeenCalled();
+    });
+
+    it('title-only change persists the title without body side-effects', async () => {
+      const document = buildDoc();
+      addTitleFragment(document, 'New Title');
+      const page = basePage({
+        content: cloneOut(document),
+        title: 'Old Title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(call[0].title).toBe('New Title');
+      expect(call[0].ydoc).toBeDefined();
+      expect(call[0].contributorIds).toBeDefined();
+      expect('content' in call[0]).toBe(false);
+      // Title-only must not touch the body-authorship provenance.
+      expect('lastUpdatedSource' in call[0]).toBe(false);
+      expect(call[1]).toBe('PAGE_ID');
+      expect(call[3].treeUpdate.title).toBe('New Title');
+
+      expect(collabHistory.addContributors).toHaveBeenCalledTimes(1);
+      expect(collabHistory.addContributors).toHaveBeenCalledWith(
+        'PAGE_ID',
+        expect.any(Array),
+      );
+      expect(document.broadcastStateless).toHaveBeenCalledTimes(1);
+      expect(transclusionService.syncPageTransclusions).not.toHaveBeenCalled();
+      expect(aiQueue.add).not.toHaveBeenCalled();
+      expect(historyQueue.add).not.toHaveBeenCalled();
+    });
+
+    it('an EMPTY title fragment does NOT overwrite a non-empty page.title (anti-corruption guard, Bug 2)', async () => {
+      // The client can momentarily seed the 'title' fragment as an EMPTY heading
+      // (hasTitleFragment true, extracted text '') before the real title syncs.
+      // Body is unchanged here, so the only candidate write is the title -> the
+      // guard must turn this into a full no-op (no updatePage, no broadcast).
+      const document = buildDoc();
+      addTitleFragment(document, ''); // empty heading: length > 0 but text ''
+      const page = basePage({
+        content: cloneOut(document),
+        title: 'Real Title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      // No write at all: the empty title is not authoritative and the body is
+      // unchanged, so onStoreDocument must take the no-op fast path.
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+      expect(document.broadcastStateless).not.toHaveBeenCalled();
+    });
+
+    it('an EMPTY title fragment alongside a body change persists the body but NOT an empty title (anti-corruption guard, Bug 2)', async () => {
+      const document = buildDoc();
+      addTitleFragment(document, ''); // empty title fragment
+      const page = basePage({
+        content: { type: 'doc', content: [] }, // different body -> bodyChanged
+        title: 'Real Title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      // Body is persisted, but the title is NOT included (empty == not
+      // authoritative) and no tree update is broadcast for the title.
+      expect(call[0].content).toBeTruthy();
+      expect('title' in call[0]).toBe(false);
+      expect(call[3]).toBeUndefined();
+    });
+
+    it('body + title change persists both with full body side-effects', async () => {
+      const document = buildDoc();
+      addTitleFragment(document, 'New Title');
+      const page = basePage({
+        content: { type: 'doc', content: [] },
+        title: 'Old Title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(call[0].content).toBeTruthy();
+      expect(call[0].title).toBe('New Title');
+      expect(call[0].ydoc).toBeDefined();
+      expect(call[0].lastUpdatedSource).toBe('user');
+      expect(call[3].treeUpdate).toBeDefined();
+
+      expect(transclusionService.syncPageTransclusions).toHaveBeenCalled();
+      expect(aiQueue.add).toHaveBeenCalled();
+      expect(historyQueue.add).toHaveBeenCalled();
+      expect(collabHistory.addContributors).toHaveBeenCalled();
+      expect(document.broadcastStateless).toHaveBeenCalled();
+    });
+
+    it('body-only change persists the body without a tree update', async () => {
+      const document = buildDoc();
+      const page = basePage({
+        content: { type: 'doc', content: [] },
+        title: 'whatever',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(call[0].content).toBeTruthy();
+      expect('title' in call[0]).toBe(false);
+      // No treeUpdate for a body-only save.
+      expect(call[3]).toBeUndefined();
+
+      expect(transclusionService.syncPageTransclusions).toHaveBeenCalled();
+      expect(aiQueue.add).toHaveBeenCalled();
+      expect(historyQueue.add).toHaveBeenCalled();
+      expect(document.broadcastStateless).toHaveBeenCalled();
+    });
+  });
+
+  describe('onLoadDocument', () => {
+    it('returns early (no DB read) when the document is not empty', async () => {
+      const document = { isEmpty: () => false };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      expect(result).toBeUndefined();
+      expect(pageRepo.findById).not.toHaveBeenCalled();
+    });
+
+    it('returns undefined and does not persist when the page is null', async () => {
+      const document = { isEmpty: () => true };
+      pageRepo.findById.mockResolvedValue(null);
+
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      expect(result).toBeUndefined();
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+    });
+
+    it('seeds + persists under a lock when the persisted ydoc lacks a title fragment', async () => {
+      const src = TiptapTransformer.toYdoc(bodyJson, 'default', tiptapExtensions);
+      const page = {
+        id: 'PAGE_ID',
+        title: 'Legacy Title',
+        ydoc: Buffer.from(Y.encodeStateAsUpdate(src)),
+        content: null,
+      };
+      // Both the cheap pre-check and the locked re-read return the same row.
+      pageRepo.findById.mockResolvedValue(page);
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      // The locked re-read must take the row lock inside the tx.
+      const lockedReadCall = pageRepo.findById.mock.calls.find(
+        (c: any[]) => c[1]?.withLock,
+      );
+      expect(lockedReadCall).toBeDefined();
+      expect(lockedReadCall[1].trx).toBe(trx);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(Buffer.isBuffer(call[0].ydoc)).toBe(true);
+      expect(call[1]).toBe('PAGE_ID');
+      // Persist must run inside the transaction.
+      expect(call[2]).toBe(trx);
+      expect(result).toBeTruthy();
+    });
+
+    it('does NOT lock or persist when the ydoc already has a title fragment', async () => {
+      const src = TiptapTransformer.toYdoc(bodyJson, 'default', tiptapExtensions);
+      Y.applyUpdate(src, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Has Title')));
+      const page = {
+        id: 'PAGE_ID',
+        title: 'Has Title',
+        ydoc: Buffer.from(Y.encodeStateAsUpdate(src)),
+        content: null,
+      };
+      pageRepo.findById.mockResolvedValue(page);
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      // Hot path: only the cheap lock-free read, no locked re-read, no write.
+      expect(pageRepo.findById).toHaveBeenCalledTimes(1);
+      expect(pageRepo.findById.mock.calls[0][1]?.withLock).toBeFalsy();
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+      expect(result).toBeTruthy();
+    });
+
+    it('converts legacy content -> ydoc inside a tx and persists a {ydoc} Buffer', async () => {
+      const page = {
+        id: 'PAGE_ID',
+        title: 'T',
+        ydoc: null,
+        content: bodyJson,
+      };
+      pageRepo.findById.mockResolvedValue(page);
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      const lockedReadCall = pageRepo.findById.mock.calls.find(
+        (c: any[]) => c[1]?.withLock,
+      );
+      expect(lockedReadCall).toBeDefined();
+      expect(lockedReadCall[1].trx).toBe(trx);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(Buffer.isBuffer(call[0].ydoc)).toBe(true);
+      expect(call[2]).toBe(trx);
+      // The rebuilt doc carries the body.
+      expect(JSON.stringify(cloneOut(result))).toContain('hello');
+    });
+
+    it('SKIPS rebuild when the locked re-read shows the ydoc was already healed', async () => {
+      // Simulate a concurrent process: the cheap pre-check sees ydoc=null (legacy
+      // rebuild path), but by the time we hold the lock another process has
+      // already persisted a healthy ydoc. We must adopt it, not rebuild/clobber.
+      const healed = TiptapTransformer.toYdoc(
+        { type: 'doc', content: [{ type: 'paragraph', content: [{ type: 'text', text: 'healed' }] }] },
+        'default',
+        tiptapExtensions,
+      );
+      Y.applyUpdate(healed, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Healed Title')));
+      const healedYdoc = Buffer.from(Y.encodeStateAsUpdate(healed));
+
+      const preCheck = { id: 'PAGE_ID', title: 'T', ydoc: null, content: bodyJson };
+      const lockedRow = {
+        id: 'PAGE_ID',
+        title: 'Healed Title',
+        ydoc: healedYdoc,
+        content: bodyJson,
+      };
+      pageRepo.findById
+        .mockResolvedValueOnce(preCheck) // cheap pre-check
+        .mockResolvedValueOnce(lockedRow); // locked re-read
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      // The healthy ydoc had a title fragment already, so nothing was rebuilt or
+      // seeded -> no clobbering write.
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+      // The returned doc is the healed body, NOT a fresh rebuild of bodyJson.
+      expect(JSON.stringify(cloneOut(result))).toContain('healed');
+    });
+
+    it('REJECTS the load when the rebuild persist fails (does not return an unpersisted doc)', async () => {
+      const page = { id: 'PAGE_ID', title: 'T', ydoc: null, content: bodyJson };
+      pageRepo.findById.mockResolvedValue(page);
+      pageRepo.updatePage.mockRejectedValue(new Error('db down'));
+      const errSpy = jest
+        .spyOn((ext as any).logger, 'error')
+        .mockImplementation(() => undefined);
+
+      const document = { isEmpty: () => true };
+      await expect(
+        ext.onLoadDocument({
+          documentName: 'page.PAGE_ID',
+          document,
+        } as any),
+      ).rejects.toThrow('db down');
+      expect(errSpy).toHaveBeenCalled();
+    });
+
+    it('seed-only persist FAILURE returns the doc from the existing ydoc (no throw)', async () => {
+      const src = TiptapTransformer.toYdoc(bodyJson, 'default', tiptapExtensions);
+      const page = {
+        id: 'PAGE_ID',
+        title: 'Legacy Title',
+        ydoc: Buffer.from(Y.encodeStateAsUpdate(src)),
+        content: null,
+      };
+      pageRepo.findById.mockResolvedValue(page);
+      pageRepo.updatePage.mockRejectedValue(new Error('db down'));
+      const errSpy = jest
+        .spyOn((ext as any).logger, 'error')
+        .mockImplementation(() => undefined);
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      // Non-fatal: we fall back to the doc loaded from the existing page.ydoc.
+      expect(result).toBeTruthy();
+      expect(JSON.stringify(cloneOut(result))).toContain('hello');
+      expect(errSpy).toHaveBeenCalled();
+    });
+  });
+});

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

@@ -3,12 +3,14 @@ import {
   Extension,
   onChangePayload,
   onLoadDocumentPayload,
+  onStatelessPayload,
   onStoreDocumentPayload,
 } from '@hocuspocus/server';
 import * as Y from 'yjs';
 import { Injectable, Logger } from '@nestjs/common';
 import { TiptapTransformer } from '@hocuspocus/transformer';
 import {
+  buildTitleSeedYdoc,
   getPageId,
   isEmptyParagraphDoc,
   jsonToText,
@@ -41,6 +43,35 @@ import {
 } from '../constants';
 import { TransclusionService } from '../../core/page/transclusion/transclusion.service';
 
+/**
+ * #251 — wire format of the client→server stateless message that signals a
+ * deliberate page clear. The client (IntentionalClear editor extension) sends
+ * `{ type: INTENTIONAL_CLEAR_MESSAGE_TYPE }`; the document is taken from the
+ * connection, not the payload, so the signal cannot be aimed at another page.
+ */
+export const INTENTIONAL_CLEAR_MESSAGE_TYPE = 'intentional-clear';
+
+/**
+ * #251 — how long an intentional-clear signal stays "pending" before it is
+ * ignored. The signal is set on the clearing keystroke but consumed by the
+ * DEBOUNCED onStoreDocument, so the TTL must comfortably exceed the collab
+ * store debounce window (hocuspocus is configured with maxDebounce = 45s in
+ * collaboration.gateway.ts). 60s leaves a margin while keeping the window for a
+ * stale flag small; on top of the TTL, any non-empty store immediately drops a
+ * pending flag (see onStoreDocument), so a "cleared then retyped" sequence can
+ * never leave a usable flag behind.
+ *
+ * Known fail-safe limitation: the flag lives only in this node's process memory.
+ * If document ownership transfers to another node, or this node crashes/restarts,
+ * between the stateless signal (set on node A) and the debounced store, the
+ * in-memory flag is lost and the clear is silently NOT applied — the store-side
+ * empty-guard then reloads the document non-empty from the DB. This is
+ * deliberately fail-safe (a lost flag preserves content rather than destroying
+ * it), but it is a documented limitation, not a guarantee that every deliberate
+ * clear survives a node handoff.
+ */
+export const INTENTIONAL_CLEAR_TTL_MS = 60_000;
+
 /**
  * Resolve the provenance source for a coalesced snapshot.
  *
@@ -96,6 +127,13 @@ export class PersistenceExtension implements Extension {
   // coalescing window" per document and OR it across all edits in the window,
   // so the snapshot is marked 'agent' regardless of who wrote last.
   private agentTouched: Map<string, boolean> = new Map();
+  // #251 — per-document "intentional clear pending" flags. Keyed by
+  // documentName, value = expiry timestamp (ms). Set by onStateless when the
+  // client reports a deliberate clear; consumed once by the next
+  // onStoreDocument empty-guard branch. This is the per-EDIT channel the
+  // per-connection context cannot provide (a clear is an edit event, but the
+  // store is debounced and connection context is fixed at authentication).
+  private intentionalClear: Map<string, number> = new Map();
 
   constructor(
     private readonly pageRepo: PageRepo,
@@ -116,6 +154,10 @@ export class PersistenceExtension implements Extension {
       return;
     }
 
+    // Cheap, lock-free pre-check (hot path stays lock-free). It tells us whether
+    // any heal (legacy rebuild and/or title seed) is needed; the heal itself
+    // re-reads the row FOR UPDATE and re-validates inside a transaction so it
+    // runs exactly once (see healUnderLock).
     const page = await this.pageRepo.findById(pageId, {
       includeContent: true,
       includeYdoc: true,
@@ -127,33 +169,193 @@ export class PersistenceExtension implements Extension {
     }
 
     if (page.ydoc) {
-      this.logger.debug(`ydoc loaded from db: ${pageId}`);
-
       const doc = new Y.Doc();
-      const dbState = new Uint8Array(page.ydoc);
+      Y.applyUpdate(doc, new Uint8Array(page.ydoc));
 
-      Y.applyUpdate(doc, dbState);
-      return doc;
+      // Legacy pages persisted their title only in the `page.title` column; the
+      // ydoc has no 'title' fragment. Decide cheaply (no lock) whether a seed is
+      // needed by inspecting the loaded doc's 'title' fragment. A seed is needed
+      // only when that fragment is empty AND there is a non-empty column title.
+      let titleSeedNeeded = false;
+      try {
+        const titleFrag = doc.get('title', Y.XmlFragment);
+        titleSeedNeeded = titleFrag.length === 0 && !!page.title?.trim();
+      } catch (err) {
+        // A malformed title fragment must not break loading; skip the seed.
+        this.logger.warn(`failed to inspect title fragment: ${err?.['message']}`);
+        titleSeedNeeded = false;
+      }
+
+      if (!titleSeedNeeded) {
+        // Fully healthy: a ydoc with a title fragment (or nothing to seed).
+        this.logger.debug(`ydoc loaded from db: ${pageId}`);
+        return doc;
+      }
+
+      // SEED-ONLY heal: a valid page.ydoc already exists; we only need to add the
+      // title fragment. If the persist fails we must NOT hand out an unpersisted
+      // fresh-client-id seed (it could later duplicate the title), so we fall
+      // back to the healthy doc loaded from the EXISTING page.ydoc, without the
+      // seed. The title just won't render until a later successful heal —
+      // non-fatal, non-corrupting.
+      try {
+        return await this.healUnderLock(pageId);
+      } catch (err) {
+        this.logger.error(
+          `Failed to persist seeded ydoc for page ${pageId}; serving existing ydoc without title seed`,
+          err,
+        );
+        return doc;
+      }
     }
 
-    // if no ydoc state in db convert json in page.content to Ydoc.
+    // NOTE (offline-sync M1, Goal 2): this per-load self-heal converts +
+    // title-seeds + persists every legacy page (content set, ydoc null) on its
+    // first open, which neutralizes the duplication trap incrementally. A
+    // proactive one-shot BATCH migration over all such pages could be added
+    // later, but it requires the tiptap schema + TiptapTransformer (Node/Yjs),
+    // which a Kysely SQL migration cannot run; no runnable-task/CLI convention
+    // exists in this repo yet, so we deliberately avoid a fragile migration.
+    //
+    // If no ydoc state in db, REBUILD a Y.Doc from the JSON in page.content under
+    // a row lock (see healUnderLock).
     if (page.content) {
-      this.logger.debug(`converting json to ydoc: ${pageId}`);
-
-      const ydoc = TiptapTransformer.toYdoc(
-        page.content,
-        'default',
-        tiptapExtensions,
-      );
-
-      Y.encodeStateAsUpdate(ydoc);
-      return ydoc;
+      // REBUILD heal: surface failures. If the persist fails we REFUSE the load
+      // (re-throw) rather than hand out an unpersisted fresh-client-id rebuild —
+      // returning it would re-arm the duplication trap. A transient DB failure
+      // means the client reconnects and retries: correctness over availability.
+      try {
+        return await this.healUnderLock(pageId);
+      } catch (err) {
+        this.logger.error(
+          `Failed to persist rebuilt ydoc for page ${pageId}; refusing load`,
+          err,
+        );
+        throw err;
+      }
     }
 
     this.logger.debug(`creating fresh ydoc: ${pageId}`);
     return new Y.Doc();
   }
 
+  /**
+   * Serialize the legacy self-heal (rebuild from page.content and/or seed the
+   * title fragment, then persist) so it runs exactly ONCE per page, closing the
+   * Yjs duplication trap. Both TiptapTransformer.toYdoc and buildTitleSeedYdoc
+   * mint FRESH Yjs client-ids every call, so two concurrent rebuilds (the API
+   * process via openDirectConnection AND the standalone collab process both
+   * seeing `ydoc IS NULL`) could each persist a different-client-id state and let
+   * a long-offline client merge-and-duplicate. We prevent that by re-reading the
+   * row FOR UPDATE inside a transaction and re-validating state under the lock:
+   * whoever wins the lock heals; the loser observes the healthy `ydoc` and adopts
+   * it instead of rebuilding. The persist happens IN THE SAME TX, so a failed
+   * write rolls back and propagates out (the caller then decides refuse vs.
+   * fall-back).
+   */
+  private async healUnderLock(pageId: string): Promise<Y.Doc> {
+    return executeTx(this.db, async (trx) => {
+      const locked = await this.pageRepo.findById(pageId, {
+        withLock: true,
+        includeContent: true,
+        includeYdoc: true,
+        trx,
+      });
+
+      const doc = new Y.Doc();
+      let rebuilt = false;
+
+      if (locked?.ydoc) {
+        // Another process already healed (or the page always had a ydoc): adopt
+        // the healthy persisted state, do NOT rebuild.
+        Y.applyUpdate(doc, new Uint8Array(locked.ydoc));
+      } else if (locked?.content) {
+        this.logger.debug(`converting json to ydoc: ${pageId}`);
+        const built = TiptapTransformer.toYdoc(
+          locked.content,
+          'default',
+          tiptapExtensions,
+        );
+        Y.applyUpdate(doc, Y.encodeStateAsUpdate(built));
+        rebuilt = true;
+      }
+      // else: no ydoc and no content -> a fresh empty doc.
+
+      // Idempotent, emptiness-guarded title seed (safe to call always).
+      const seeded = this.seedTitleFragment(doc, locked?.title ?? null);
+
+      if (rebuilt || seeded) {
+        // Persist IN THE SAME TX. If this throws, the tx rolls back and the
+        // error propagates out of executeTx to the caller.
+        await this.pageRepo.updatePage(
+          { ydoc: Buffer.from(Y.encodeStateAsUpdate(doc)) },
+          pageId,
+          trx,
+        );
+        this.logger.debug(`persisted rebuilt/seeded ydoc: ${pageId}`);
+      }
+
+      return doc;
+    });
+  }
+
+  /**
+   * Seed the 'title' fragment of `doc` from the `page.title` column for legacy
+   * pages whose persisted ydoc has no title fragment yet.
+   *
+   * Guarded STRICTLY by emptiness: we only seed when the existing 'title'
+   * fragment is empty AND there is a non-empty column title. Seeding a non-empty
+   * fragment would re-introduce the Yjs duplication trap, so we never do it.
+   * Returns true when a seed was applied (so the caller can persist).
+   * Defensive: a malformed title must not break document loading.
+   */
+  private seedTitleFragment(doc: Y.Doc, title: string | null): boolean {
+    const trimmed = (title ?? '').trim();
+    if (!trimmed) return false;
+
+    try {
+      const titleFrag = doc.get('title', Y.XmlFragment);
+      if (titleFrag.length !== 0) return false;
+
+      const titleSeed = buildTitleSeedYdoc(title);
+      Y.applyUpdate(doc, Y.encodeStateAsUpdate(titleSeed));
+      this.logger.debug('seeded title fragment from page.title column');
+      return true;
+    } catch (err) {
+      this.logger.warn(`failed to seed title fragment: ${err?.['message']}`);
+      return false;
+    }
+  }
+
+  /**
+   * Persist an already-encoded Y.Doc state directly to `page.ydoc`, mirroring the
+   * `pageRepo.updatePage({ ydoc })` write that onStoreDocument uses.
+   *
+   * Used by the gateway's writePageTitle (F1, variant C). A REST/MCP/agent rename
+   * with no live editor writes the new title into the in-memory 'title' fragment,
+   * but onStoreDocument's no-op fast-path (page.title column already equals the
+   * new title) does NOT persist that in-memory fragment, so the stored `page.ydoc`
+   * keeps the OLD title — and a later body edit then reverts the rename (loads the
+   * OLD fragment, sees it differs from the column, overwrites the column back to
+   * OLD). Writing the ydoc here keeps the persisted fragment consistent with the
+   * column so the rename survives.
+   *
+   * Broadcast-safe / no double broadcast: this carries no `treeUpdate`, so the
+   * tree WS + redis listeners (which gate on `treeUpdate`) do NOT re-broadcast the
+   * rename — only PageService.update's own PAGE_UPDATED does. The only extra
+   * side-effect is an idempotent search reindex.
+   *
+   * Idempotent and lock-free, so it is safe whether or not a live editor is
+   * connected: Yjs state is cumulative, so a concurrent onStoreDocument simply
+   * persists a superset of this state later.
+   */
+  async persistTitleFragmentYdoc(
+    pageId: string,
+    ydocState: Buffer,
+  ): Promise<void> {
+    await this.pageRepo.updatePage({ ydoc: ydocState }, pageId);
+  }
+
   async onStoreDocument(data: onStoreDocumentPayload) {
     const { documentName, document, context } = data;
 
@@ -171,7 +373,34 @@ export class PersistenceExtension implements Extension {
       this.logger.warn('jsonToText' + err?.['message']);
     }
 
+    // Title lives in the SAME Y.Doc as the body, in a dedicated 'title' fragment
+    // (the collaborative title-editor contract with the client). Extract it
+    // defensively: a malformed title fragment must NOT crash the document store.
+    // `hasTitleFragment` distinguishes "the doc actually carries a title
+    // fragment" from "legacy doc with no title fragment" — only the former may
+    // write page.title, so a legacy doc never clobbers the column with ''.
+    let titleText = '';
+    let hasTitleFragment = false;
+    try {
+      const titleFrag = document.get('title', Y.XmlFragment);
+      hasTitleFragment = !!titleFrag && titleFrag.length > 0;
+      if (hasTitleFragment) {
+        const titleJson = TiptapTransformer.fromYdoc(document, 'title');
+        titleText = titleJson ? jsonToText(titleJson).trim() : '';
+      }
+    } catch (err) {
+      this.logger.warn('title extraction: ' + err?.['message']);
+      hasTitleFragment = false;
+    }
+
     let page: Page = null;
+    // Tracks whether the BODY ('default') changed in this store. The heavy
+    // body-only side-effects (transclusion sync, mentions, RAG, history) stay
+    // gated on this so a title-only change does not trigger them.
+    let bodyChanged = false;
+    // Tracks a successful title-only persist so the post-tx contributor folding
+    // (collabHistory.addContributors) runs for the title-only case too.
+    let titleOnlyPersisted = false;
     const editingUserIds = this.consumeContributors(documentName);
     // Sticky agent marker: 'agent' if any agent edit landed in this window, OR
     // if the current writer is the agent (covers a store with no prior onChange
@@ -180,6 +409,19 @@ export class PersistenceExtension implements Extension {
       this.consumeAgentTouched(documentName),
       context?.actor,
     );
+    // #251 — consume the intentional-clear flag ONCE, BEFORE the retry loop
+    // (like consumeContributors / consumeAgentTouched above). consumeIntentional-
+    // Clear ALWAYS deletes the in-memory Map entry, but a tx rollback cannot
+    // un-delete it. Calling it INSIDE the loop meant: a clear armed for attempt 1
+    // was consumed there, attempt 1's updatePage threw a transient error and
+    // rolled back, then attempt 2 re-read non-empty content and saw the flag
+    // already gone — silently downgrading the retry into a BLOCKED write, so the
+    // user's deliberate clear was dropped. Hoisting makes the decision stable
+    // across every attempt. This single call also preserves the "a non-empty
+    // store drops a pending flag" semantics (the cleared-then-retyped case):
+    // every store consumes the flag here regardless of incoming emptiness, so a
+    // subsequent non-empty store can never leave a usable flag behind.
+    const allowIntentionalClear = this.consumeIntentionalClear(documentName);
 
     // Persist with a small bounded retry. The in-memory Y.Doc is the ONLY copy
     // of the latest edit until this hook returns: hocuspocus destroys/unloads the
@@ -205,11 +447,120 @@ export class PersistenceExtension implements Extension {
             return;
           }
 
-          if (isDeepStrictEqual(tiptapJson, page.content)) {
+          bodyChanged = !isDeepStrictEqual(tiptapJson, page.content);
+          // Only a populated 'title' fragment may update page.title; compare
+          // against the current column value (treat null as '').
+          //
+          // ANTI-CORRUPTION GUARD (Bug 2): the client's collaborative title-editor
+          // can momentarily initialize the 'title' fragment as an EMPTY heading
+          // (so `hasTitleFragment` is true, but the extracted `titleText` is '')
+          // BEFORE the server's real-title seed has synced. Writing that '' would
+          // silently wipe a non-empty page.title to "untitled". A wiki page is
+          // never legitimately retitled to empty via this path, so we treat an
+          // empty extracted title as "not authoritative" and never persist it.
+          // The `titleText.length > 0` clause makes this guard apply to BOTH the
+          // title-only branch and the body+title branch below.
+          //
+          // DELIBERATE: this intentionally makes it impossible to retitle a page
+          // to EMPTY via the collab path — a wiki page is never legitimately
+          // empty-titled. If a non-empty-title rule ever needs relaxing or
+          // enforcing differently, the REST UpdatePageDto is the place to validate
+          // the title, not this collab guard.
+          const titleChanged =
+            hasTitleFragment &&
+            titleText.length > 0 &&
+            titleText !== (page.title ?? '');
+
+          // No-op fast path: neither body nor title changed.
+          if (!bodyChanged && !titleChanged) {
             page = null;
             return;
           }
 
+          // Title-only change: the body is unchanged, so skip the heavy body
+          // history/contributor logic and persist just the new title and the
+          // ydoc (the title fragment edit lives in the same ydoc). The early-skip
+          // used to drop this case entirely, losing the title change.
+          if (!bodyChanged) {
+            // Fold the window's editing users into contributors the same way the
+            // body branch does, so a user who edited ONLY the title is not dropped
+            // from page.contributorIds.
+            const contributorIds = Array.from(
+              new Set([
+                ...(page.contributorIds || []),
+                ...editingUserIds,
+                page.creatorId,
+              ]),
+            );
+            await this.pageRepo.updatePage(
+              {
+                title: titleText,
+                ydoc: ydocState,
+                lastUpdatedById: context.user.id,
+                contributorIds,
+                // A title-only change is not a body-authorship transition; leave
+                // lastUpdatedSource/aiChatId untouched so the user->agent history
+                // boundary in the body branch is not bypassed.
+              },
+              pageId,
+              trx,
+              // Mirror PageService.update's tree snapshot so a collaborative rename
+              // propagates to other users' sidebar/breadcrumbs like the REST rename.
+              {
+                treeUpdate: {
+                  id: pageId,
+                  slugId: page.slugId,
+                  spaceId: page.spaceId,
+                  parentPageId: page.parentPageId ?? null,
+                  title: titleText,
+                },
+              },
+            );
+            this.logger.debug(`Page title updated: ${pageId} - SlugId: ${page.slugId}`);
+            titleOnlyPersisted = true;
+            return;
+          }
+
+          // #206 persist-6 / #248 — store-side empty-guard. A momentarily-empty
+          // live Y.Doc (a client/agent glitch, a bad merge, a transclusion that
+          // emptied) must NOT overwrite non-empty persisted content. The LOAD
+          // path already guards emptiness (onLoadDocument only hydrates from db
+          // when the live doc isEmpty); the STORE path did not, so an empty
+          // serialization was written straight over the page, wiping it
+          // silently.
+          //
+          // #251 — the ONE legitimate empty-over-non-empty write is a user who
+          // deliberately clears the page. That intent arrives out-of-band as a
+          // stateless message, NOT from the doc content, which is why it cannot
+          // be spoofed for non-clear writes: the flag is only ever read on this
+          // empty-incoming branch, so the worst a forged signal can do is clear
+          // a page the connection may already edit. The flag was consumed ONCE
+          // before the retry loop (`allowIntentionalClear`) so the decision is
+          // stable across retries; a non-empty store still drops any pending
+          // flag via that same hoisted consume (a "cleared then retyped"
+          // sequence can't leave a usable one behind).
+          const incomingEmpty = isEmptyParagraphDoc(tiptapJson as any);
+          if (
+            incomingEmpty &&
+            page.content &&
+            !isEmptyParagraphDoc(page.content as any)
+          ) {
+            if (allowIntentionalClear) {
+              this.logger.debug(
+                `Intentional clear for ${pageId}: persisting empty doc over ` +
+                  `non-empty content (user-signalled)`,
+              );
+              // fall through — the empty write is allowed exactly once.
+            } else {
+              this.logger.warn(
+                `Skipping store for ${pageId}: empty live doc would overwrite ` +
+                  `non-empty persisted content`,
+              );
+              page = null;
+              return;
+            }
+          }
+
           let contributorIds = undefined;
           try {
             const existingContributors = page.contributorIds || [];
@@ -227,29 +578,22 @@ export class PersistenceExtension implements Extension {
           // Approach A — boundary snapshot before the agent's first edit.
           // When this store is the agent's and the page's currently persisted
           // state was authored by a human, pin that human state as its own
-          // history version BEFORE the agent overwrites it. `page` still holds
-          // the OLD content/provenance here, so saveHistory(page) captures the
-          // pre-agent state tagged 'user'. The agent's new content is
-          // snapshotted later by the debounced PAGE_HISTORY job ('agent'). Skip
-          // if the prior state is already agent-authored (boundary already
-          // pinned on the user->agent transition), if the page is effectively
-          // empty, or if the latest existing snapshot already equals this human
-          // state (avoid duplicates).
-          if (
-            lastUpdatedSource === 'agent' &&
-            page.lastUpdatedSource !== 'agent'
-          ) {
+          // history version BEFORE the agent overwrites it. `page` still holds the
+          // OLD content/provenance here, so saveHistory(page) captures the
+          // pre-agent state tagged 'user'. The agent's new content is snapshotted
+          // later by the debounced PAGE_HISTORY job ('agent'). Skip if the prior
+          // state is already agent-authored (boundary already pinned on the
+          // user->agent transition), if the page is effectively empty, or if the
+          // latest existing snapshot already equals this human state (avoid
+          // duplicates).
+          if (lastUpdatedSource === 'agent' && page.lastUpdatedSource !== 'agent') {
             const lastHistory = await this.pageHistoryRepo.findPageLastHistory(
               pageId,
               { includeContent: true, trx },
             );
             const humanBaselineMissing =
-              !lastHistory ||
-              !isDeepStrictEqual(lastHistory.content, page.content);
-            if (
-              !isEmptyParagraphDoc(page.content as any) &&
-              humanBaselineMissing
-            ) {
+              !lastHistory || !isDeepStrictEqual(lastHistory.content, page.content);
+            if (!isEmptyParagraphDoc(page.content as any) && humanBaselineMissing) {
               await this.pageHistoryRepo.saveHistory(page, {
                 contributorIds: page.contributorIds ?? undefined,
                 trx,
@@ -267,9 +611,27 @@ export class PersistenceExtension implements Extension {
               lastUpdatedSource,
               lastUpdatedAiChatId: context?.aiChatId ?? null,
               contributorIds: contributorIds,
+              // Persist the title in the SAME transaction when the title fragment
+              // changed alongside the body.
+              ...(titleChanged ? { title: titleText } : {}),
             },
             pageId,
             trx,
+            // Mirror PageService.update's tree snapshot so a collaborative rename
+            // propagates to other users' sidebar/breadcrumbs like the REST rename.
+            // Only attach when the title actually changed; a body-only save must
+            // not trigger a tree broadcast.
+            titleChanged
+              ? {
+                  treeUpdate: {
+                    id: pageId,
+                    slugId: page.slugId,
+                    spaceId: page.spaceId,
+                    parentPageId: page.parentPageId ?? null,
+                    title: titleText,
+                  },
+                }
+              : undefined,
           );
 
           this.logger.debug(`Page updated: ${pageId} - SlugId: ${page.slugId}`);
@@ -290,6 +652,8 @@ export class PersistenceExtension implements Extension {
       }
     }
 
+    // `page` is truthy whenever anything was persisted (body OR title-only), so
+    // the page.updated broadcast fires for a title-only change too.
     if (page) {
       document.broadcastStateless(
         JSON.stringify({
@@ -307,11 +671,20 @@ export class PersistenceExtension implements Extension {
             : undefined,
         }),
       );
+    }
 
+    // Record the window's editing users in collab history for a title-only
+    // change too (the body branch does this below, gated on bodyChanged).
+    if (page && titleOnlyPersisted) {
+      await this.collabHistory.addContributors(pageId, editingUserIds);
+    }
+
+    // Body-only side-effects: skip them for a title-only change (body unchanged).
+    if (page && bodyChanged) {
       await this.syncTransclusion(pageId, page.workspaceId, tiptapJson);
     }
 
-    if (page) {
+    if (page && bodyChanged) {
       await this.collabHistory.addContributors(pageId, editingUserIds);
 
       const mentions = extractMentions(tiptapJson);
@@ -345,6 +718,37 @@ export class PersistenceExtension implements Extension {
     }
   }
 
+  /**
+   * #251 — receive the client's deliberate-clear signal. Records a short-lived,
+   * single-use pending flag for the originating document so the next
+   * onStoreDocument may let one empty-over-non-empty write through the guard.
+   *
+   * Hardening: read-only connections cannot arm the flag, and the document is
+   * taken from the connection (`data.documentName`), never the payload, so a
+   * client cannot target a page it isn't editing. The flag only ever RELAXES
+   * the guard for an empty write (a clear); it can never force or alter a
+   * non-empty write, so it is not a guard bypass for normal content.
+   */
+  async onStateless(data: onStatelessPayload) {
+    const { connection, documentName, payload } = data;
+
+    if (connection?.readOnly) return;
+
+    let message: { type?: string } | undefined;
+    try {
+      message = JSON.parse(payload);
+    } catch {
+      return; // unrelated / malformed stateless message
+    }
+
+    if (message?.type !== INTENTIONAL_CLEAR_MESSAGE_TYPE) return;
+
+    this.intentionalClear.set(
+      documentName,
+      Date.now() + INTENTIONAL_CLEAR_TTL_MS,
+    );
+  }
+
   async onChange(data: onChangePayload) {
     const documentName = data.documentName;
     const userId = data.context?.user?.id;
@@ -368,6 +772,7 @@ export class PersistenceExtension implements Extension {
     const documentName = data.documentName;
     this.contributors.delete(documentName);
     this.agentTouched.delete(documentName);
+    this.intentionalClear.delete(documentName);
   }
 
   private consumeContributors(documentName: string): string[] {
@@ -385,6 +790,18 @@ export class PersistenceExtension implements Extension {
     return touched;
   }
 
+  /**
+   * #251 — read and clear the intentional-clear flag for this document. Returns
+   * true only if a flag was pending AND still within its TTL. Always deletes the
+   * entry so the signal is strictly single-use (one clear → one allowed empty
+   * write); an expired flag is treated as absent (guard still blocks).
+   */
+  private consumeIntentionalClear(documentName: string): boolean {
+    const expiry = this.intentionalClear.get(documentName);
+    this.intentionalClear.delete(documentName);
+    return expiry !== undefined && Date.now() < expiry;
+  }
+
   private async enqueuePageHistory(
     page: Page,
     lastUpdatedSource: string,

apps/server/src/collaboration/listeners/page-tree-bridge.publisher.spec.ts

@@ -0,0 +1,81 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { RedisService } from '@nestjs-labs/nestjs-ioredis';
+import { PageTreeBridgePublisher } from './page-tree-bridge.publisher';
+import { COLLAB_TREE_UPDATE_CHANNEL } from '../constants';
+import {
+  PageEvent,
+  TreeUpdateSnapshot,
+} from '../../database/listeners/page.listener';
+
+const treeUpdate: TreeUpdateSnapshot = {
+  id: 'page-1',
+  slugId: 'slug-1',
+  spaceId: 'space-1',
+  parentPageId: null,
+  title: 'Renamed',
+  icon: '🚀',
+};
+
+describe('PageTreeBridgePublisher', () => {
+  let publisher: PageTreeBridgePublisher;
+  let redis: { publish: jest.Mock };
+
+  beforeEach(async () => {
+    redis = { publish: jest.fn().mockResolvedValue(1) };
+    const redisService = { getOrThrow: () => redis } as unknown as RedisService;
+
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        PageTreeBridgePublisher,
+        { provide: RedisService, useValue: redisService },
+      ],
+    }).compile();
+
+    publisher = module.get<PageTreeBridgePublisher>(PageTreeBridgePublisher);
+  });
+
+  it('WITH a `treeUpdate`: publishes the JSON snapshot on the channel', async () => {
+    const event: PageEvent = {
+      pageIds: ['page-1'],
+      workspaceId: 'ws-1',
+      treeUpdate,
+    };
+
+    await publisher.onPageUpdated(event);
+
+    expect(redis.publish).toHaveBeenCalledTimes(1);
+    expect(redis.publish).toHaveBeenCalledWith(
+      COLLAB_TREE_UPDATE_CHANNEL,
+      JSON.stringify(treeUpdate),
+    );
+  });
+
+  it('content-only save (NO `treeUpdate`): does NOT publish', async () => {
+    const event: PageEvent = {
+      pageIds: ['page-1'],
+      workspaceId: 'ws-1',
+    };
+
+    await publisher.onPageUpdated(event);
+
+    expect(redis.publish).not.toHaveBeenCalled();
+  });
+
+  it('a publish rejection is caught (no throw)', async () => {
+    redis.publish.mockRejectedValueOnce(new Error('redis down'));
+    const errorSpy = jest
+      .spyOn(publisher['logger'], 'error')
+      .mockImplementation(() => undefined);
+
+    const event: PageEvent = {
+      pageIds: ['page-1'],
+      workspaceId: 'ws-1',
+      treeUpdate,
+    };
+
+    await expect(publisher.onPageUpdated(event)).resolves.toBeUndefined();
+    expect(errorSpy).toHaveBeenCalledTimes(1);
+
+    errorSpy.mockRestore();
+  });
+});

apps/server/src/collaboration/listeners/page-tree-bridge.publisher.ts

@@ -0,0 +1,55 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { RedisService } from '@nestjs-labs/nestjs-ioredis';
+import type { Redis } from 'ioredis';
+import { EventName } from '../../common/events/event.contants';
+import { PageEvent } from '../../database/listeners/page.listener';
+import { COLLAB_TREE_UPDATE_CHANNEL } from '../constants';
+
+/**
+ * Collab-process half of the cross-process tree-update bridge.
+ *
+ * The standalone collab process bootstraps `CollabAppModule`, which does NOT
+ * import `WsModule`/`PageWsListener`. So when a collaborative title/icon rename
+ * persists and emits `EventName.PAGE_UPDATED` with a `treeUpdate` snapshot, there
+ * is no listener in this process to broadcast it — the live tree update would be
+ * lost for 2-process (COLLAB_URL set) deployments.
+ *
+ * This publisher fills that gap: it forwards the `treeUpdate` snapshot over a
+ * Redis pub/sub channel to the API process, which re-broadcasts it via
+ * `WsTreeService` (the single broadcast authority).
+ *
+ * It is registered ONLY in `CollabAppModule.providers`, so it never runs in the
+ * API process (where `PageWsListener` already broadcasts the same event locally).
+ * That module placement is what prevents a double broadcast. In single-process
+ * mode `CollabAppModule` is not loaded at all, so this publisher never runs.
+ */
+@Injectable()
+export class PageTreeBridgePublisher {
+  private readonly logger = new Logger(PageTreeBridgePublisher.name);
+  private readonly redis: Redis;
+
+  constructor(private readonly redisService: RedisService) {
+    this.redis = this.redisService.getOrThrow();
+  }
+
+  @OnEvent(EventName.PAGE_UPDATED)
+  async onPageUpdated(event: PageEvent): Promise<void> {
+    // Mirror PageWsListener's gating: only title/icon changes carry a snapshot.
+    // Content-only saves leave `treeUpdate` undefined and are ignored.
+    if (!event.treeUpdate) return;
+
+    try {
+      await this.redis.publish(
+        COLLAB_TREE_UPDATE_CHANNEL,
+        JSON.stringify(event.treeUpdate),
+      );
+    } catch (err) {
+      // A Redis publish failure must not break the store path.
+      this.logger.error(
+        `Failed to publish tree update to ${COLLAB_TREE_UPDATE_CHANNEL}`,
+        err instanceof Error ? err.stack : String(err),
+      );
+    }
+  }
+}

apps/server/src/collaboration/server/collab-app.module.ts

@@ -20,6 +20,7 @@ import { CaslModule } from '../../core/casl/casl.module';
 import { ThrottleModule } from '../../integrations/throttle/throttle.module';
 import { CacheModule } from '@nestjs/cache-manager';
 import KeyvRedis from '@keyv/redis';
+import { PageTreeBridgePublisher } from '../listeners/page-tree-bridge.publisher';
 
 @Module({
   imports: [
@@ -54,6 +55,6 @@ import KeyvRedis from '@keyv/redis';
       ? [CollaborationController]
       : []),
   ],
-  providers: [AppService],
+  providers: [AppService, PageTreeBridgePublisher],
 })
 export class CollabAppModule {}

apps/server/src/collaboration/title-rename-durability.spec.ts

@@ -0,0 +1,187 @@
+import * as Y from 'yjs';
+import { TiptapTransformer } from '@hocuspocus/transformer';
+import { CollaborationGateway } from './collaboration.gateway';
+import { PersistenceExtension } from './extensions/persistence.extension';
+import {
+  buildTitleSeedYdoc,
+  jsonToText,
+  tiptapExtensions,
+} from './collaboration.util';
+
+/**
+ * F1 (variant C) — rename durability for a page with an already-persisted Yjs
+ * 'title' fragment and NO live editor (the REST/MCP/agent rename path).
+ *
+ * The bug: PageService.update writes the NEW title to the `page.title` COLUMN,
+ * then calls gateway.writePageTitle, which loads the page's ydoc (fragment =
+ * OLD) and overwrites it to NEW in memory. On disconnect, onStoreDocument sees
+ * titleText(NEW) === column(NEW) → no-op fast-path → it does NOT persist the
+ * in-memory fragment. So `page.ydoc` keeps the OLD title, and a LATER body edit
+ * loads the OLD fragment, sees it differs from the column, and silently reverts
+ * the column back to OLD.
+ *
+ * The fix: writePageTitle persists the 'title' fragment to `page.ydoc` DIRECTLY
+ * (via PersistenceExtension.persistTitleFragmentYdoc) after the transact, so the
+ * persisted fragment and the column stay consistent.
+ *
+ * This test drives the REAL writePageTitle + the REAL onStoreDocument against an
+ * in-memory page row, so it FAILS on the pre-fix no-op behaviour and PASSES after.
+ */
+
+const PAGE_ID = '550e8400-e29b-41d4-a716-446655440000';
+const USER_ID = 'user-1';
+const OLD_TITLE = 'Old Title';
+const NEW_TITLE = 'Renamed Title';
+
+const bodyJson = (text: string) => ({
+  type: 'doc',
+  content: [{ type: 'paragraph', content: [{ type: 'text', text }] }],
+});
+
+// Build the initial persisted ydoc carrying BOTH a 'title' fragment and a body.
+const makeInitialYdoc = (title: string, body: any): Buffer => {
+  const doc = new Y.Doc();
+  Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc(title)));
+  Y.applyUpdate(
+    doc,
+    Y.encodeStateAsUpdate(TiptapTransformer.toYdoc(body, 'default', tiptapExtensions)),
+  );
+  return Buffer.from(Y.encodeStateAsUpdate(doc));
+};
+
+// Load a doc from a persisted buffer (mirrors openDirectConnection loading from
+// persistence when no editor is connected). hocuspocus augments the live doc
+// with broadcastStateless(); a bare Y.Doc lacks it, so stub it.
+const loadDoc = (buf: Buffer): Y.Doc => {
+  const doc = new Y.Doc();
+  if (buf) Y.applyUpdate(doc, new Uint8Array(buf));
+  (doc as any).broadcastStateless = jest.fn();
+  return doc;
+};
+
+// Read the 'title' fragment text from a persisted buffer.
+const readTitle = (buf: Buffer): string => {
+  const doc = loadDoc(buf);
+  const titleJson = TiptapTransformer.fromYdoc(doc, 'title');
+  return titleJson ? jsonToText(titleJson).trim() : '';
+};
+
+describe('rename durability (F1 variant C): persisted title fragment survives a body edit', () => {
+  it('persists the renamed title into page.ydoc so a later body edit does not revert it', async () => {
+    // In-memory page row = the DB.
+    const row: any = {
+      id: PAGE_ID,
+      slugId: 'slug-1',
+      spaceId: 'space-1',
+      workspaceId: 'ws-1',
+      creatorId: 'creator-1',
+      contributorIds: ['creator-1'],
+      createdAt: new Date('2020-01-01T00:00:00Z'),
+      lastUpdatedSource: 'user',
+      title: OLD_TITLE,
+      // content column mirrors the normalized body in the ydoc.
+      content: TiptapTransformer.fromYdoc(
+        loadDoc(makeInitialYdoc(OLD_TITLE, bodyJson('BODY V1'))),
+        'default',
+      ),
+      ydoc: makeInitialYdoc(OLD_TITLE, bodyJson('BODY V1')),
+    };
+
+    const pageRepo = {
+      findById: jest.fn(async () => ({ ...row })),
+      updatePage: jest.fn(async (data: any, _pageId?: string) => {
+        Object.assign(row, data, { updatedAt: new Date() });
+      }),
+    };
+    const pageHistoryRepo = {
+      saveHistory: jest.fn().mockResolvedValue(undefined),
+      findPageLastHistory: jest.fn().mockResolvedValue(null),
+    };
+    const noopQueue = { add: jest.fn().mockResolvedValue(undefined) };
+    const collabHistory = { addContributors: jest.fn().mockResolvedValue(undefined) };
+    const transclusionService = {
+      syncPageTransclusions: jest.fn().mockResolvedValue(undefined),
+      syncPageReferences: jest.fn().mockResolvedValue(undefined),
+      syncPageTemplateReferences: jest.fn().mockResolvedValue(undefined),
+    };
+    // db whose transaction().execute(fn) runs fn with a trx stub (drives the
+    // real executeTx helper without a database).
+    const db = {
+      transaction: () => ({
+        execute: (fn: (trx: any) => Promise<any>) => fn({ __trx: true }),
+      }),
+    };
+
+    const ext = new PersistenceExtension(
+      pageRepo as any,
+      pageHistoryRepo as any,
+      db as any,
+      noopQueue as any,
+      noopQueue as any,
+      noopQueue as any,
+      collabHistory as any,
+      transclusionService as any,
+    );
+    jest.spyOn(ext['logger'], 'debug').mockImplementation(() => undefined);
+    jest.spyOn(ext['logger'], 'warn').mockImplementation(() => undefined);
+    jest.spyOn(ext['logger'], 'error').mockImplementation(() => undefined);
+
+    const documentName = `page.${PAGE_ID}`;
+    // Fake hocuspocus: openDirectConnection loads a doc from the CURRENT persisted
+    // ydoc (no live editor) and, on disconnect, runs the real onStoreDocument —
+    // exactly the no-live-editor unload path.
+    const fakeHocuspocus = {
+      openDirectConnection: jest.fn(async (name: string, context: any) => {
+        const liveDoc = loadDoc(row.ydoc);
+        return {
+          transact: async (fn: (doc: Y.Doc) => void) => fn(liveDoc),
+          disconnect: async () => {
+            await ext.onStoreDocument({
+              documentName: name,
+              document: liveDoc,
+              context,
+            } as any);
+          },
+        };
+      }),
+    };
+
+    const gateway: CollaborationGateway = Object.create(
+      CollaborationGateway.prototype,
+    );
+    (gateway as any).hocuspocus = fakeHocuspocus;
+    (gateway as any).persistenceExtension = ext;
+
+    // --- REST/service rename (no live editor) ---
+    // 1) PageService.update writes the NEW title to the column.
+    await pageRepo.updatePage({ title: NEW_TITLE }, PAGE_ID);
+    // 2) PageService.update syncs the Yjs 'title' fragment.
+    await gateway.writePageTitle(PAGE_ID, NEW_TITLE, {
+      user: { id: USER_ID } as any,
+    });
+
+    // Reload the persisted ydoc: the 'title' fragment must now be NEW.
+    // (Pre-fix this is still OLD — writePageTitle did not persist the fragment.)
+    expect(readTitle(row.ydoc)).toBe(NEW_TITLE);
+
+    // --- a later body edit must NOT revert the title ---
+    const editDoc = loadDoc(row.ydoc);
+    const frag = editDoc.getXmlFragment('default');
+    const p = new Y.XmlElement('paragraph');
+    const t = new Y.XmlText();
+    t.insert(0, 'appended');
+    p.insert(0, [t]);
+    frag.insert(frag.length, [p]);
+
+    await ext.onStoreDocument({
+      documentName,
+      document: editDoc,
+      context: { user: { id: USER_ID } },
+    } as any);
+
+    // The body edit was persisted, and the title stayed NEW in BOTH the column
+    // and the persisted ydoc fragment (pre-fix the column reverts to OLD).
+    expect(row.title).toBe(NEW_TITLE);
+    expect(readTitle(row.ydoc)).toBe(NEW_TITLE);
+  });
+});

apps/server/src/collaboration/yjs.util.spec.ts

@@ -0,0 +1,278 @@
+import * as Y from 'yjs';
+import { getSchema } from '@tiptap/core';
+import {
+  initProseMirrorDoc,
+  absolutePositionToRelativePosition,
+  prosemirrorJSONToYDoc,
+} from '@tiptap/y-tiptap';
+import { tiptapExtensions } from './collaboration.util';
+import {
+  setYjsMark,
+  removeYjsMarkByAttribute,
+  updateYjsMarkAttribute,
+  type YjsSelection,
+} from './yjs.util';
+
+/**
+ * Unit tests for the server-side Yjs mark helpers used by the collaboration
+ * handler to set/resolve/delete comment marks directly on the shared Y.Doc
+ * (collaboration.handler.ts: setCommentMark / resolveCommentMark).
+ *
+ * The fragment shape mirrors production exactly: a `default` XmlFragment whose
+ * children are block XmlElements (paragraph) holding XmlText runs. For setYjsMark
+ * the selection is a pair of Yjs RelativePosition JSONs (what the client sends);
+ * we synthesize them from known ProseMirror absolute positions via
+ * absolutePositionToRelativePosition so the marked range is deterministic.
+ */
+
+const schema = getSchema(tiptapExtensions);
+
+// Build a real Y.Doc from ProseMirror JSON (same path the collab handler uses
+// via TiptapTransformer) and return the doc + its `default` fragment.
+function buildFromPm(pmJson: unknown) {
+  const ydoc = prosemirrorJSONToYDoc(
+    schema,
+    pmJson as never,
+    'default',
+  ) as unknown as Y.Doc;
+  const fragment = ydoc.getXmlFragment('default');
+  return { ydoc, fragment };
+}
+
+// Make a YjsSelection (anchor/head RelativePosition JSON) for two ProseMirror
+// absolute positions in `fragment`.
+function selectionFor(
+  fragment: Y.XmlFragment,
+  anchorPos: number,
+  headPos: number,
+): YjsSelection {
+  const { mapping } = initProseMirrorDoc(fragment, schema);
+  const anchor = absolutePositionToRelativePosition(
+    anchorPos,
+    fragment as never,
+    mapping,
+  );
+  const head = absolutePositionToRelativePosition(
+    headPos,
+    fragment as never,
+    mapping,
+  );
+  return {
+    anchor: Y.relativePositionToJSON(anchor),
+    head: Y.relativePositionToJSON(head),
+  };
+}
+
+// The XmlText run of the i-th top-level paragraph.
+function paragraphText(fragment: Y.XmlFragment, index = 0): Y.XmlText {
+  const para = fragment.get(index) as Y.XmlElement;
+  return para.get(0) as Y.XmlText;
+}
+
+// --- raw fragment builder for the remove/update tests (no schema needed) ---
+//
+// removeYjsMarkByAttribute / updateYjsMarkAttribute only read item.toDelta() and
+// call item.format(); they never touch the ProseMirror schema. Build the runs
+// directly so we control which segment carries which comment attrs.
+function buildWithComments(
+  segments: Array<{
+    text: string;
+    comment?: { commentId: string; resolved: boolean };
+  }>,
+): { fragment: Y.XmlFragment; text: Y.XmlText } {
+  const ydoc = new Y.Doc();
+  const fragment = ydoc.getXmlFragment('default');
+  const para = new Y.XmlElement('paragraph');
+  fragment.insert(0, [para]);
+  const text = new Y.XmlText();
+  para.insert(0, [text]);
+  let offset = 0;
+  for (const seg of segments) {
+    text.insert(offset, seg.text);
+    if (seg.comment) {
+      text.format(offset, seg.text.length, { comment: seg.comment });
+    }
+    offset += seg.text.length;
+  }
+  return { fragment, text };
+}
+
+describe('setYjsMark', () => {
+  it('applies the mark over exactly the selected sub-range (PM pos 1..6 = "Hello")', () => {
+    const { ydoc, fragment } = buildFromPm({
+      type: 'doc',
+      content: [
+        { type: 'paragraph', content: [{ type: 'text', text: 'Hello world' }] },
+      ],
+    });
+    // PM pos 1 = start of the paragraph text; pos 6 = just after "Hello".
+    const sel = selectionFor(fragment, 1, 6);
+
+    setYjsMark(ydoc as never, fragment, sel, 'comment', {
+      commentId: 'c1',
+      resolved: false,
+    });
+
+    // The run splits: "Hello" carries the comment mark, " world" stays clean.
+    expect(paragraphText(fragment).toDelta()).toEqual([
+      {
+        insert: 'Hello',
+        attributes: { comment: { commentId: 'c1', resolved: false } },
+      },
+      { insert: ' world' },
+    ]);
+  });
+
+  it('normalizes a reversed selection (head before anchor) to the same range', () => {
+    const { ydoc, fragment } = buildFromPm({
+      type: 'doc',
+      content: [
+        { type: 'paragraph', content: [{ type: 'text', text: 'Hello world' }] },
+      ],
+    });
+    // anchor=6, head=1 — reversed; setYjsMark takes min/max so it marks "Hello".
+    const sel = selectionFor(fragment, 6, 1);
+
+    setYjsMark(ydoc as never, fragment, sel, 'comment', {
+      commentId: 'c2',
+      resolved: false,
+    });
+
+    expect(paragraphText(fragment).toDelta()).toEqual([
+      {
+        insert: 'Hello',
+        attributes: { comment: { commentId: 'c2', resolved: false } },
+      },
+      { insert: ' world' },
+    ]);
+  });
+
+  it('marks across two paragraphs (range spans an element boundary)', () => {
+    const { ydoc, fragment } = buildFromPm({
+      type: 'doc',
+      content: [
+        { type: 'paragraph', content: [{ type: 'text', text: 'aaa' }] },
+        { type: 'paragraph', content: [{ type: 'text', text: 'bbb' }] },
+      ],
+    });
+    // PM positions: "aaa" = 1..4; the </p><p> boundary consumes pos 4 and 5, so
+    // "bbb" starts at pos 6 (chars at 6,7,8). Select pos 2 (inside "aaa") to pos
+    // 8 (after the second "b").
+    const sel = selectionFor(fragment, 2, 8);
+
+    setYjsMark(ydoc as never, fragment, sel, 'comment', {
+      commentId: 'c3',
+      resolved: false,
+    });
+
+    // First paragraph: "a" clean, "aa" marked.
+    expect(paragraphText(fragment, 0).toDelta()).toEqual([
+      { insert: 'a' },
+      {
+        insert: 'aa',
+        attributes: { comment: { commentId: 'c3', resolved: false } },
+      },
+    ]);
+    // Second paragraph: "bb" marked, "b" clean.
+    expect(paragraphText(fragment, 1).toDelta()).toEqual([
+      {
+        insert: 'bb',
+        attributes: { comment: { commentId: 'c3', resolved: false } },
+      },
+      { insert: 'b' },
+    ]);
+  });
+});
+
+describe('removeYjsMarkByAttribute', () => {
+  it('removes only the run whose attribute value matches, leaving others', () => {
+    const { fragment, text } = buildWithComments([
+      { text: 'AAA', comment: { commentId: 'c1', resolved: false } },
+      { text: 'BBB', comment: { commentId: 'c2', resolved: false } },
+    ]);
+
+    removeYjsMarkByAttribute(fragment, 'comment', 'commentId', 'c1');
+
+    // c1's run loses the mark; c2's run is untouched.
+    expect(text.toDelta()).toEqual([
+      { insert: 'AAA' },
+      {
+        insert: 'BBB',
+        attributes: { comment: { commentId: 'c2', resolved: false } },
+      },
+    ]);
+  });
+
+  it('does nothing when no run carries the requested value (no-match branch)', () => {
+    const { fragment, text } = buildWithComments([
+      { text: 'AAA', comment: { commentId: 'c1', resolved: false } },
+    ]);
+    const before = text.toDelta();
+
+    removeYjsMarkByAttribute(fragment, 'comment', 'commentId', 'does-not-exist');
+
+    expect(text.toDelta()).toEqual(before);
+  });
+
+  it('leaves a different mark type alone', () => {
+    // A run carrying only `bold` must survive a comment removal pass.
+    const ydoc = new Y.Doc();
+    const fragment = ydoc.getXmlFragment('default');
+    const para = new Y.XmlElement('paragraph');
+    fragment.insert(0, [para]);
+    const text = new Y.XmlText();
+    para.insert(0, [text]);
+    text.insert(0, 'XYZ');
+    text.format(0, 3, { bold: true });
+
+    removeYjsMarkByAttribute(fragment, 'comment', 'commentId', 'c1');
+
+    expect(text.toDelta()).toEqual([
+      { insert: 'XYZ', attributes: { bold: true } },
+    ]);
+  });
+});
+
+describe('updateYjsMarkAttribute', () => {
+  it('merges new attributes into the matching run, preserving the rest', () => {
+    const { fragment, text } = buildWithComments([
+      { text: 'AAA', comment: { commentId: 'c1', resolved: false } },
+      { text: 'BBB', comment: { commentId: 'c2', resolved: false } },
+    ]);
+
+    updateYjsMarkAttribute(
+      fragment,
+      'comment',
+      { name: 'commentId', value: 'c1' },
+      { resolved: true },
+    );
+
+    // c1's run flips resolved=true (commentId preserved via merge); c2 untouched.
+    expect(text.toDelta()).toEqual([
+      {
+        insert: 'AAA',
+        attributes: { comment: { commentId: 'c1', resolved: true } },
+      },
+      {
+        insert: 'BBB',
+        attributes: { comment: { commentId: 'c2', resolved: false } },
+      },
+    ]);
+  });
+
+  it('does nothing when no run matches (no-match branch)', () => {
+    const { fragment, text } = buildWithComments([
+      { text: 'AAA', comment: { commentId: 'c1', resolved: false } },
+    ]);
+    const before = text.toDelta();
+
+    updateYjsMarkAttribute(
+      fragment,
+      'comment',
+      { name: 'commentId', value: 'nope' },
+      { resolved: true },
+    );
+
+    expect(text.toDelta()).toEqual(before);
+  });
+});

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

@@ -3,6 +3,8 @@ import { PageRepo } from '@docmost/db/repos/page/page.repo';
 import { PageEmbeddingRepo } from '@docmost/db/repos/ai-chat/page-embedding.repo';
 import { KyselyDB } from '@docmost/db/types/kysely.types';
 import { AiService } from '../../../integrations/ai/ai.service';
+import { EmbeddingReindexProgressService } from '../../../integrations/ai/embedding-reindex-progress.service';
+import { AiEmbeddingNotConfiguredException } from '../../../integrations/ai/ai-embedding-not-configured.exception';
 
 /**
  * Unit tests for EmbeddingIndexerService.reindexWorkspace's batch control flow.
@@ -12,7 +14,8 @@ import { AiService } from '../../../integrations/ai/ai.service';
  * reindexWorkspace actually touches:
  *   - aiService.getEmbeddingModel -> a model string so the up-front configured
  *     check passes,
- *   - pageRepo.getIdsByWorkspace -> three page ids,
+ *   - pageRepo.getEmbeddablePageIds -> three page ids (the embeddable set the
+ *     reindex iterates),
  *   - service.reindexPage -> spied per test to drive the per-page outcome.
  *
  * The point under test is the catch block: a FATAL provider error (auth/billing)
@@ -24,21 +27,30 @@ describe('EmbeddingIndexerService.reindexWorkspace fail-fast', () => {
 
   function makeService() {
     const pageRepo = {
-      getIdsByWorkspace: jest.fn().mockResolvedValue(['p1', 'p2', 'p3']),
+      getEmbeddablePageIds: jest.fn().mockResolvedValue(['p1', 'p2', 'p3']),
     };
     const pageEmbeddingRepo = {};
     const aiService = {
       getEmbeddingModel: jest.fn().mockResolvedValue('some-model'),
     };
+    // Progress is a best-effort cosmetic store; mock its async methods so the
+    // batch control flow can be tested without Redis.
+    const reindexProgress = {
+      start: jest.fn().mockResolvedValue(undefined),
+      increment: jest.fn().mockResolvedValue(undefined),
+      clear: jest.fn().mockResolvedValue(undefined),
+      get: jest.fn().mockResolvedValue(null),
+    };
     const db = {};
 
     const service = new EmbeddingIndexerService(
       pageRepo as unknown as PageRepo,
       pageEmbeddingRepo as unknown as PageEmbeddingRepo,
       aiService as unknown as AiService,
+      reindexProgress as unknown as EmbeddingReindexProgressService,
       db as unknown as KyselyDB,
     );
-    return { service, pageRepo, aiService };
+    return { service, pageRepo, aiService, reindexProgress };
   }
 
   it('aborts after the first page on a FATAL (401) provider error', async () => {
@@ -78,3 +90,100 @@ describe('EmbeddingIndexerService.reindexWorkspace fail-fast', () => {
     expect(reindexPage).toHaveBeenCalledTimes(3);
   });
 });
+
+/**
+ * Live reindex-progress reporting: reindexWorkspace must publish a per-workspace
+ * progress record (total at start, done incremented per processed page) and ALWAYS
+ * clear it in a finally — including on a fatal abort and an unconfigured early
+ * return — so the settings status can show the counter climb without ever getting
+ * stuck in a "reindexing" state.
+ */
+describe('EmbeddingIndexerService.reindexWorkspace progress', () => {
+  const WORKSPACE_ID = 'ws-1';
+
+  function makeService(pageIds: string[] = ['p1', 'p2', 'p3']) {
+    const pageRepo = {
+      getEmbeddablePageIds: jest.fn().mockResolvedValue(pageIds),
+    };
+    const pageEmbeddingRepo = {};
+    const aiService = {
+      getEmbeddingModel: jest.fn().mockResolvedValue('some-model'),
+    };
+    const reindexProgress = {
+      start: jest.fn().mockResolvedValue(undefined),
+      increment: jest.fn().mockResolvedValue(undefined),
+      clear: jest.fn().mockResolvedValue(undefined),
+      get: jest.fn().mockResolvedValue(null),
+    };
+    const db = {};
+    const service = new EmbeddingIndexerService(
+      pageRepo as unknown as PageRepo,
+      pageEmbeddingRepo as unknown as PageEmbeddingRepo,
+      aiService as unknown as AiService,
+      reindexProgress as unknown as EmbeddingReindexProgressService,
+      db as unknown as KyselyDB,
+    );
+    return { service, pageRepo, aiService, reindexProgress };
+  }
+
+  it('sets total at start, increments done per page, and clears in finally', async () => {
+    const { service, reindexProgress } = makeService(['p1', 'p2', 'p3']);
+    jest.spyOn(service, 'reindexPage').mockResolvedValue(undefined);
+
+    await service.reindexWorkspace(WORKSPACE_ID);
+
+    expect(reindexProgress.start).toHaveBeenCalledWith(WORKSPACE_ID, 3);
+    // One increment per processed page.
+    expect(reindexProgress.increment).toHaveBeenCalledTimes(3);
+    expect(reindexProgress.increment).toHaveBeenCalledWith(WORKSPACE_ID);
+    // Cleared exactly once on completion.
+    expect(reindexProgress.clear).toHaveBeenCalledTimes(1);
+    expect(reindexProgress.clear).toHaveBeenCalledWith(WORKSPACE_ID);
+  });
+
+  it('counts a handled (non-fatal) per-page failure as processed', async () => {
+    const { service, reindexProgress } = makeService(['p1', 'p2', 'p3']);
+    // No statusCode -> non-fatal -> isolate and continue; each counts as done.
+    jest.spyOn(service, 'reindexPage').mockRejectedValue(new Error('boom'));
+
+    await service.reindexWorkspace(WORKSPACE_ID);
+
+    expect(reindexProgress.increment).toHaveBeenCalledTimes(3);
+    expect(reindexProgress.clear).toHaveBeenCalledTimes(1);
+  });
+
+  it('clears progress in finally even when a FATAL provider error aborts the batch', async () => {
+    const { service, reindexProgress } = makeService(['p1', 'p2', 'p3']);
+    // A 401 aborts on the first page (re-thrown) — the finally must still clear.
+    jest
+      .spyOn(service, 'reindexPage')
+      .mockRejectedValue({ statusCode: 401, message: 'User not found' });
+
+    await expect(service.reindexWorkspace(WORKSPACE_ID)).rejects.toMatchObject({
+      statusCode: 401,
+    });
+
+    expect(reindexProgress.start).toHaveBeenCalledWith(WORKSPACE_ID, 3);
+    // Aborted page is NOT counted as processed.
+    expect(reindexProgress.increment).not.toHaveBeenCalled();
+    // But progress is still cleared so the run never gets stuck.
+    expect(reindexProgress.clear).toHaveBeenCalledTimes(1);
+  });
+
+  it('clears the enqueue-seeded progress on an unconfigured early return', async () => {
+    const { service, aiService, reindexProgress } = makeService();
+    // Embeddings not configured: reindexWorkspace returns early WITHOUT starting
+    // a fresh record, but the finally must still clear the enqueue-time seed.
+    aiService.getEmbeddingModel = jest
+      .fn()
+      .mockRejectedValue(new AiEmbeddingNotConfiguredException());
+
+    await expect(
+      service.reindexWorkspace(WORKSPACE_ID),
+    ).resolves.toBeUndefined();
+
+    expect(reindexProgress.start).not.toHaveBeenCalled();
+    expect(reindexProgress.clear).toHaveBeenCalledTimes(1);
+    expect(reindexProgress.clear).toHaveBeenCalledWith(WORKSPACE_ID);
+  });
+});

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

@@ -9,6 +9,7 @@ import { KyselyDB } from '@docmost/db/types/kysely.types';
 import { InjectKysely } from 'nestjs-kysely';
 import { executeTx } from '@docmost/db/utils';
 import { AiService } from '../../../integrations/ai/ai.service';
+import { EmbeddingReindexProgressService } from '../../../integrations/ai/embedding-reindex-progress.service';
 import { AiEmbeddingNotConfiguredException } from '../../../integrations/ai/ai-embedding-not-configured.exception';
 import {
   describeProviderError,
@@ -48,6 +49,7 @@ export class EmbeddingIndexerService {
     private readonly pageRepo: PageRepo,
     private readonly pageEmbeddingRepo: PageEmbeddingRepo,
     private readonly aiService: AiService,
+    private readonly reindexProgress: EmbeddingReindexProgressService,
     @InjectKysely() private readonly db: KyselyDB,
   ) {}
 
@@ -183,7 +185,19 @@ export class EmbeddingIndexerService {
   }
 
   /**
-   * (Re)build embeddings for EVERY non-deleted page in a workspace. Used by the
+   * (Re)build embeddings for the EMBEDDABLE page set of a workspace — the same
+   * set countEmbeddablePages counts (via getEmbeddablePageIds): non-deleted pages
+   * that qualify under any of the three clauses of `embeddablePredicate` —
+   * non-empty textContent, OR an empty/null textContent whose ProseMirror
+   * `content` JSON has at least one text node (`"type":"text"`) that `jsonToText`
+   * can extract, OR an already-stored (non-deleted) embedding row — NOT every
+   * non-deleted page. Iterating this set keeps the live `total` equal to the
+   * steady-state denominator, so the progress counter climbs 0 -> total and
+   * matches the before/after DB coverage exactly. A page with truly no
+   * extractable text (empty textContent AND content with only non-text/atom
+   * nodes such as math) is correctly skipped (reindexPage no-ops on it); a page
+   * that lost its text but still has stale embeddings stays in the set (the
+   * EXISTS clause) so it is visited and its stale rows are cleared. Used by the
    * bulk reindex (WORKSPACE_CREATE_EMBEDDINGS, fired when AI Search is enabled
    * and by the manual "Reindex now" action).
    *
@@ -194,69 +208,99 @@ export class EmbeddingIndexerService {
    * the batch.
    */
   async reindexWorkspace(workspaceId: string): Promise<void> {
+    // The whole run is wrapped so the per-workspace progress record is ALWAYS
+    // cleared in the finally — on success, on a fatal-provider abort, on an
+    // unconfigured early-return, or on any unexpected throw — so a failed run
+    // never leaves a stuck "reindexing" state (the status then falls back to the
+    // steady-state DB coverage count). A placeholder record may already exist
+    // (seeded at enqueue time); the finally cleans that too.
     try {
-      await this.aiService.getEmbeddingModel(workspaceId);
-    } catch (err) {
-      if (err instanceof AiEmbeddingNotConfiguredException) {
-        this.logger.log(
-          `reindexWorkspace: embeddings not configured for workspace ${workspaceId}, skipping`,
-        );
-        return;
-      }
-      throw err;
-    }
-
-    const pageIds = await this.pageRepo.getIdsByWorkspace(workspaceId);
-    const total = pageIds.length;
-    const startedAt = Date.now();
-    this.logger.log(
-      `reindexWorkspace: starting reindex of ${total} page(s) for workspace ${workspaceId}`,
-    );
-
-    let failed = 0;
-    for (let i = 0; i < total; i++) {
-      const pageId = pageIds[i];
-      const position = i + 1;
-      // Log BEFORE the await: if the embedding call hangs, this is the last line
-      // in the log and it names the exact page that is stuck.
-      this.logger.log(
-        `reindexWorkspace: [${position}/${total}] indexing page ${pageId} (workspace ${workspaceId})`,
-      );
-      const pageStartedAt = Date.now();
       try {
-        await this.reindexPage(pageId);
-        const elapsed = Date.now() - pageStartedAt;
-        if (elapsed >= SLOW_PAGE_MS) {
-          this.logger.warn(
-            `reindexWorkspace: [${position}/${total}] page ${pageId} took ${elapsed}ms`,
-          );
-        }
+        await this.aiService.getEmbeddingModel(workspaceId);
       } catch (err) {
-        // A fatal provider error (invalid/missing key, no credits) recurs
-        // identically on EVERY remaining page. Abort the whole batch instead of
-        // issuing hundreds of doomed requests against the provider.
-        if (isFatalProviderError(err)) {
-          this.logger.error(
-            `reindexWorkspace: aborting at [${position}/${total}] for workspace ` +
-              `${workspaceId} — fatal provider error, remaining pages would fail ` +
-              `identically: ${describeProviderError(err)}`,
+        if (err instanceof AiEmbeddingNotConfiguredException) {
+          this.logger.log(
+            `reindexWorkspace: embeddings not configured for workspace ${workspaceId}, skipping`,
           );
-          throw err;
+          return;
         }
-        // Per-page isolation: one non-fatal failure (incl. an embedding timeout)
-        // must not abort the whole batch.
-        failed++;
-        this.logger.error(
-          `reindexWorkspace: [${position}/${total}] failed to reindex page ${pageId} ` +
-            `after ${Date.now() - pageStartedAt}ms: ${describeProviderError(err)}`,
-        );
+        throw err;
       }
-    }
 
-    this.logger.log(
-      `reindexWorkspace: done for workspace ${workspaceId}: ` +
-        `${total - failed}/${total} indexed, ${failed} failed in ${Date.now() - startedAt}ms`,
-    );
+      // Iterate the EMBEDDABLE set (same three-clause predicate as
+      // countEmbeddablePages), NOT every non-deleted page: this makes `total`
+      // here equal the steady-state denominator, so the live counter climbs
+      // 0 -> total and matches the before/after DB count exactly (no
+      // 478 -> 500 -> 478 denominator jump). Pages whose text lives in the
+      // ProseMirror `content` JSON (a text node) even with empty text_content ARE
+      // in this set (the content-JSON clause) and get embedded; a page with no
+      // extractable text at all is correctly skipped — reindexPage no-ops on it —
+      // and a page that lost its text but still has stale embeddings IS in this
+      // set (the EXISTS clause) so it is still visited and its stale rows cleared.
+      const pageIds = await this.pageRepo.getEmbeddablePageIds(workspaceId);
+      const total = pageIds.length;
+      const startedAt = Date.now();
+      // Publish the live run progress over this same set (done reset to 0). The
+      // counter increments once per iterated page and reaches exactly `total`,
+      // which equals countEmbeddablePages — the steady-state denominator.
+      await this.reindexProgress.start(workspaceId, total);
+      this.logger.log(
+        `reindexWorkspace: starting reindex of ${total} page(s) for workspace ${workspaceId}`,
+      );
+
+      let failed = 0;
+      for (let i = 0; i < total; i++) {
+        const pageId = pageIds[i];
+        const position = i + 1;
+        // Log BEFORE the await: if the embedding call hangs, this is the last line
+        // in the log and it names the exact page that is stuck.
+        this.logger.log(
+          `reindexWorkspace: [${position}/${total}] indexing page ${pageId} (workspace ${workspaceId})`,
+        );
+        const pageStartedAt = Date.now();
+        try {
+          await this.reindexPage(pageId);
+          // Count this page as processed (matches the [position/total] log).
+          await this.reindexProgress.increment(workspaceId);
+          const elapsed = Date.now() - pageStartedAt;
+          if (elapsed >= SLOW_PAGE_MS) {
+            this.logger.warn(
+              `reindexWorkspace: [${position}/${total}] page ${pageId} took ${elapsed}ms`,
+            );
+          }
+        } catch (err) {
+          // A fatal provider error (invalid/missing key, no credits) recurs
+          // identically on EVERY remaining page. Abort the whole batch instead of
+          // issuing hundreds of doomed requests against the provider. Do NOT count
+          // it as processed — the run aborts here (the finally clears progress).
+          if (isFatalProviderError(err)) {
+            this.logger.error(
+              `reindexWorkspace: aborting at [${position}/${total}] for workspace ` +
+                `${workspaceId} — fatal provider error, remaining pages would fail ` +
+                `identically: ${describeProviderError(err)}`,
+            );
+            throw err;
+          }
+          // Per-page isolation: one non-fatal failure (incl. an embedding timeout)
+          // must not abort the whole batch. A handled failure still advances the
+          // counter (matches the [position/total] log, so done reaches total).
+          failed++;
+          await this.reindexProgress.increment(workspaceId);
+          this.logger.error(
+            `reindexWorkspace: [${position}/${total}] failed to reindex page ${pageId} ` +
+              `after ${Date.now() - pageStartedAt}ms: ${describeProviderError(err)}`,
+          );
+        }
+      }
+
+      this.logger.log(
+        `reindexWorkspace: done for workspace ${workspaceId}: ` +
+          `${total - failed}/${total} indexed, ${failed} failed in ${Date.now() - startedAt}ms`,
+      );
+    } finally {
+      // Always remove the progress record so the status reverts to the DB count.
+      await this.reindexProgress.clear(workspaceId);
+    }
   }
 
   /** Purge ALL embeddings for a workspace (WORKSPACE_DELETE_EMBEDDINGS). */

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

@@ -0,0 +1,166 @@
+import { McpClientsService } from './mcp-clients.service';
+
+/**
+ * Unit tests for the two security-critical surfaces of McpClientsService that the
+ * sibling specs (ssrf-guard / validate-resolved-addresses / lease) do NOT cover:
+ *
+ *  1. `decryptHeaders` (private) — FAIL-OPEN behavior. A decrypt/parse failure
+ *     (e.g. APP_SECRET rotated, tampered blob) must NEVER throw and must NEVER
+ *     log the blob: it returns `undefined` so the connect proceeds WITHOUT the
+ *     now-unreadable auth headers (which then 401s and the server is skipped),
+ *     rather than crashing the whole turn.
+ *
+ *  2. `this.guardedFetch` (private, bound to the SSRF-pinned dispatcher) — the
+ *     per-request DNS-rebinding guard. A blocked host (private/loopback/metadata
+ *     IP literal, or an unparseable URL) must REJECT before any socket is opened;
+ *     a public host is allowed through to the real `fetch` with the pinned
+ *     dispatcher attached.
+ *
+ * No network and no DB: the repo + secretBox deps are stubbed, and global `fetch`
+ * is mocked for the single allow-path assertion.
+ */
+
+// Build the service with a SecretBoxService stub whose decryptSecret is supplied
+// per-test. The repo dep is unused by the methods under test.
+function buildService(decryptSecret: (blob: string) => string) {
+  const secretBox = { decryptSecret: jest.fn(decryptSecret) };
+  const service = new McpClientsService({} as never, secretBox as never);
+  return { service, secretBox };
+}
+
+describe('McpClientsService.decryptHeaders', () => {
+  // Reach the private method via the as-any pattern common in these NestJS specs.
+  const callDecrypt = (
+    service: McpClientsService,
+    blob: string | null,
+  ): Record<string, string> | undefined =>
+    (
+      service as unknown as {
+        decryptHeaders: (b: string | null) => Record<string, string> | undefined;
+      }
+    ).decryptHeaders(blob);
+
+  it('returns undefined for a null blob without decrypting', () => {
+    const { service, secretBox } = buildService(() => '{}');
+    expect(callDecrypt(service, null)).toBeUndefined();
+    expect(secretBox.decryptSecret).not.toHaveBeenCalled();
+  });
+
+  it('decrypts a valid blob and keeps only string-valued headers', () => {
+    const { service } = buildService(() =>
+      JSON.stringify({
+        Authorization: 'Bearer abc',
+        'X-Api-Key': 'k',
+        // Non-string values must be dropped, not coerced.
+        count: 5,
+        flag: true,
+        nested: { a: 1 },
+      }),
+    );
+    expect(callDecrypt(service, 'cipher')).toEqual({
+      Authorization: 'Bearer abc',
+      'X-Api-Key': 'k',
+    });
+  });
+
+  it('returns undefined when the decrypted object has no string headers', () => {
+    const { service } = buildService(() => JSON.stringify({ count: 5 }));
+    // No usable headers -> undefined (connect with no auth header), not {}.
+    expect(callDecrypt(service, 'cipher')).toBeUndefined();
+  });
+
+  it('FAILS OPEN: a decrypt error returns undefined instead of throwing', () => {
+    const { service } = buildService(() => {
+      throw new Error('Failed to decrypt secret — APP_SECRET may have changed');
+    });
+    const warnSpy = jest
+      .spyOn(
+        (service as unknown as { logger: { warn: (...a: unknown[]) => void } })
+          .logger,
+        'warn',
+      )
+      .mockImplementation(() => undefined);
+
+    let result: unknown;
+    expect(() => {
+      result = callDecrypt(service, 'tampered-blob');
+    }).not.toThrow();
+    expect(result).toBeUndefined();
+    // It warns (so ops sees degradation) but never logs the blob itself.
+    expect(warnSpy).toHaveBeenCalledTimes(1);
+    expect(String(warnSpy.mock.calls[0]?.[0])).not.toContain('tampered-blob');
+  });
+
+  it('FAILS OPEN: malformed JSON (decrypts to non-JSON) returns undefined', () => {
+    const { service } = buildService(() => 'not-json{');
+    jest
+      .spyOn(
+        (service as unknown as { logger: { warn: (...a: unknown[]) => void } })
+          .logger,
+        'warn',
+      )
+      .mockImplementation(() => undefined);
+    expect(callDecrypt(service, 'cipher')).toBeUndefined();
+  });
+});
+
+describe('McpClientsService.guardedFetch (SSRF per-request guard)', () => {
+  // The bound guardedFetch closure lives on the instance as a private field.
+  const guardedFetchOf = (service: McpClientsService) =>
+    (service as unknown as { guardedFetch: typeof fetch }).guardedFetch;
+
+  let fetchSpy: jest.SpiedFunction<typeof fetch>;
+
+  beforeEach(() => {
+    // Any reachable real fetch would be a network call; assert per-test that the
+    // blocked paths never reach it, and stub a Response for the allow path.
+    fetchSpy = jest
+      .spyOn(global, 'fetch')
+      .mockResolvedValue(new Response('ok', { status: 200 }));
+  });
+
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  const blocked: Array<[string, string]> = [
+    ['loopback IPv4', 'http://127.0.0.1/mcp'],
+    ['private 10/8', 'http://10.0.0.5/mcp'],
+    ['private 192.168/16', 'http://192.168.1.1/mcp'],
+    ['cloud metadata link-local', 'http://169.254.169.254/latest/meta-data/'],
+    ['loopback IPv6 (bracketed)', 'http://[::1]:8080/mcp'],
+  ];
+
+  it.each(blocked)(
+    'rejects a request to %s without opening a socket',
+    async (_label, url) => {
+      const { service } = buildService(() => '{}');
+      await expect(guardedFetchOf(service)(url)).rejects.toThrow(
+        /blocked request/,
+      );
+      expect(fetchSpy).not.toHaveBeenCalled();
+    },
+  );
+
+  it('rejects an unparseable URL as a blocked request', async () => {
+    const { service } = buildService(() => '{}');
+    await expect(
+      guardedFetchOf(service)('::: not a url :::'),
+    ).rejects.toThrow('blocked request: invalid URL');
+    expect(fetchSpy).not.toHaveBeenCalled();
+  });
+
+  it('allows a public IP literal and forwards through the pinned dispatcher', async () => {
+    const { service } = buildService(() => '{}');
+    const res = await guardedFetchOf(service)('http://8.8.8.8/mcp');
+
+    expect(res.status).toBe(200);
+    expect(fetchSpy).toHaveBeenCalledTimes(1);
+    // The init MUST carry the SSRF-pinned undici dispatcher (the rebinding pin);
+    // dropping it would let undici do a second, unchecked DNS resolution.
+    const init = fetchSpy.mock.calls[0][1] as RequestInit & {
+      dispatcher?: unknown;
+    };
+    expect(init.dispatcher).toBeDefined();
+  });
+});

apps/server/src/core/ai-chat/tools/docmost-client.loader.ts

@@ -5,6 +5,34 @@ import { pathToFileURL } from 'node:url';
  * ESM-only `@docmost/mcp` package. We only need the constructor + the read/write
  * methods used by the per-user tool adapter; the full client surface lives in
  * `packages/mcp/src/client.ts`. Signatures here mirror that file exactly.
+ *
+ * DRIFT GUARD: the method NAMES below are runtime-checked against the real
+ * `DocmostClient` by `packages/mcp/test/unit/client-host-contract.test.mjs`
+ * (which can import the ESM class directly). If you rename/remove a method here
+ * or in client.ts, that test fails — so a stale mirror cannot silently ship a
+ * runtime "x is not a function" into an agent tool call. Keep the two in sync.
+ *
+ * STAGED PLAN — full derivation `DocmostClientLike = <real DocmostClient type>`
+ * (issue #193, layer 3) is intentionally NOT done; it stays a hand-mirror for
+ * now because of two verified blockers across the ESM(mcp)/CJS(server) boundary:
+ *   1. `@docmost/mcp` emits NO declaration files (its tsconfig has no
+ *      `declaration`, package.json has no `types`/types-export) and the server
+ *      tsconfig has no path mapping for it — the server only loads it via the
+ *      runtime `import()` trick below, so there is no type to import today.
+ *   2. The real client methods have inferred, CONCRETE return types; the in-app
+ *      tool adapter reads results through loose `Record<string,unknown>` returns
+ *      + `as` casts (e.g. `(result?.data ?? {}) as { title?: string }`).
+ *      Deriving the exact type would make those casts non-overlapping ("may be a
+ *      mistake") and break the build, and `Partial<DocmostClientLike>` test stubs
+ *      would have to satisfy the full concrete surface.
+ * To do it safely later (incrementally): (a) turn on `declaration: true` in
+ * packages/mcp/tsconfig.json + add a `types` export condition and commit the
+ * emitted `.d.ts`; (b) `import type { DocmostClient } from '@docmost/mcp'` here
+ * and replace this interface with a `Pick<DocmostClient, ...>` of the consumed
+ * methods; (c) audit every `as` cast in ai-chat-tools.service.ts against the now
+ * concrete return types (double-cast through `unknown` only where genuinely
+ * needed); (d) keep the runtime guard test as a belt-and-braces check. Until
+ * then the guard test above is the cheap, behaviour-neutral protection.
  */
 export interface DocmostClientLike {
   // --- read ---

apps/server/src/core/ai-chat/tools/shared-tool-specs.contract.spec.ts

@@ -0,0 +1,124 @@
+import { z } from 'zod';
+import { AiChatToolsService } from './ai-chat-tools.service';
+import * as loader from './docmost-client.loader';
+import type { DocmostClientLike } from './docmost-client.loader';
+// The real zod-agnostic registry, imported from source so the contract is checked
+// against exactly what the @docmost/mcp package ships (no hand-stub).
+import { SHARED_TOOL_SPECS } from '../../../../../../packages/mcp/src/tool-specs';
+
+/**
+ * CONTRACT: SHARED_TOOL_SPECS <-> in-app tool wiring parity.
+ *
+ * `packages/mcp/src/tool-specs.ts` is the single source of truth for the tools
+ * that are intentionally IDENTICAL across the standalone MCP server (zod v3) and
+ * the in-app AI-SDK service (zod v4). The in-app service builds each one via
+ * `sharedTool(sharedToolSpecs.<key>, execute)`, keyed by the spec's `inAppKey`.
+ *
+ * This test fails the build if a spec is added to the registry but never wired
+ * in-app, if an `inAppKey` is renamed without updating the service, if the
+ * description drifts between the registry and the exposed tool, if the
+ * snake_case `mcpName` <-> camelCase `inAppKey` convention is broken, or if the
+ * exposed tool's input-schema keys diverge from the spec's `buildShape`.
+ *
+ * It does NOT need @docmost/mcp built: the registry is imported from TS source,
+ * and the ESM loader is mocked so `forUser()` never dynamically imports the
+ * package.
+ */
+describe('SHARED_TOOL_SPECS contract parity', () => {
+  // Empty fake client: no tool is executed here — every assertion is on tool
+  // presence / metadata / schema, so the client methods are never called.
+  const fakeClient: Partial<DocmostClientLike> = {};
+  const tokenServiceStub = {
+    generateAccessToken: jest.fn().mockResolvedValue('access-token'),
+    generateCollabToken: jest.fn().mockResolvedValue('collab-token'),
+  };
+
+  let tools: Record<string, unknown>;
+
+  beforeAll(async () => {
+    jest.spyOn(loader, 'loadDocmostMcp').mockResolvedValue({
+      DocmostClient: function () {
+        return fakeClient as DocmostClientLike;
+      } as unknown as loader.DocmostClientCtor,
+      // Feed the service the SAME registry this test asserts against.
+      sharedToolSpecs: SHARED_TOOL_SPECS as unknown as Record<
+        string,
+        loader.SharedToolSpec
+      >,
+    });
+    const service = new AiChatToolsService(
+      tokenServiceStub as never,
+      {} as never,
+      {} as never,
+      {} as never,
+      {} as never,
+      { asSink: () => ({ put: jest.fn(), has: jest.fn(), evict: jest.fn() }) } as never,
+    );
+    tools = (await service.forUser(
+      { id: 'user-1', email: 'u@example.com', workspaceId: 'ws-1' } as never,
+      'session-1',
+      'ws-1',
+      'chat-1',
+    )) as unknown as Record<string, unknown>;
+  });
+
+  afterAll(() => jest.restoreAllMocks());
+
+  // camelCase -> snake_case, matching the registry's mcpName convention.
+  const toSnake = (s: string) =>
+    s.replace(/[A-Z]/g, (c) => `_${c.toLowerCase()}`);
+
+  // Type as the (optional-buildShape) SharedToolSpec; the `satisfies` literal
+  // above otherwise narrows to a union where some members lack buildShape.
+  const specEntries = Object.entries(SHARED_TOOL_SPECS) as Array<
+    [string, loader.SharedToolSpec]
+  >;
+
+  // Sanity: the registry is non-empty, so the per-spec table below is not vacuous.
+  it('registry is non-empty', () => {
+    expect(specEntries.length).toBeGreaterThan(0);
+  });
+
+  describe.each(specEntries)('spec "%s"', (registryKey, spec) => {
+    it('registry key equals its inAppKey', () => {
+      // The service indexes the registry by property name; a key != inAppKey
+      // would wire the wrong (or no) tool.
+      expect(spec.inAppKey).toBe(registryKey);
+    });
+
+    it('mcpName is the snake_case form of inAppKey', () => {
+      expect(spec.mcpName).toBe(toSnake(spec.inAppKey));
+    });
+
+    it('is exposed in-app under its inAppKey', () => {
+      // Fails if a spec is added to the registry but never wired in forUser().
+      expect(tools[spec.inAppKey]).toBeDefined();
+    });
+
+    it("exposed tool's description matches the registry description", () => {
+      const tool = tools[spec.inAppKey] as { description: string };
+      expect(tool.description).toBe(spec.description);
+    });
+
+    it("exposed tool's input-schema keys match buildShape (incl. required)", () => {
+      const tool = tools[spec.inAppKey] as {
+        inputSchema: { jsonSchema: { properties?: Record<string, unknown>; required?: string[] } };
+      };
+      const json = tool.inputSchema.jsonSchema;
+      const actualKeys = Object.keys(json.properties ?? {}).sort();
+
+      // Derive the spec's declared shape with THIS layer's zod (v4) — the same
+      // call the service makes — then compare key sets and required-ness.
+      const shape = spec.buildShape ? spec.buildShape(z) : {};
+      const expectedKeys = Object.keys(shape).sort();
+      expect(actualKeys).toEqual(expectedKeys);
+
+      // A non-.optional() field must surface as required in the advertised schema.
+      const expectedRequired = Object.entries(shape)
+        .filter(([, field]) => !(field as z.ZodTypeAny).isOptional?.())
+        .map(([k]) => k)
+        .sort();
+      expect((json.required ?? []).slice().sort()).toEqual(expectedRequired);
+    });
+  });
+});

apps/server/src/core/auth/auth.controller.spec.ts

@@ -19,4 +19,87 @@ describe('AuthController', () => {
   it('should be defined', () => {
     expect(controller).toBeDefined();
   });
+
+  // The EE MFA module is absent in this repo, so require() throws and is caught;
+  // login falls through to authService.login -> setAuthCookie -> returnToken.
+  describe('login returnToken branch', () => {
+    const workspace = { id: 'ws1', enforceSso: false };
+
+    const makeController = () => {
+      const authService = {
+        login: jest.fn().mockResolvedValue('jwt-token-123'),
+      };
+      const environmentService = {
+        getCookieExpiresIn: jest.fn().mockReturnValue(new Date()),
+        isHttps: jest.fn().mockReturnValue(false),
+      };
+      const ctrl = new AuthController(
+        authService as any,
+        {} as any,
+        environmentService as any,
+        {} as any,
+        {} as any,
+      );
+      const res = { setCookie: jest.fn() };
+      return { ctrl, authService, res };
+    };
+
+    it('returns the body token and sets the cookie when returnToken is true', async () => {
+      const { ctrl, authService, res } = makeController();
+      const loginInput = {
+        email: 'a@b.com',
+        password: 'pw',
+        returnToken: true,
+      };
+
+      const result = await ctrl.login(
+        workspace as any,
+        res as any,
+        loginInput as any,
+      );
+
+      expect(result).toEqual({ authToken: 'jwt-token-123' });
+      expect(res.setCookie).toHaveBeenCalledTimes(1);
+      expect(res.setCookie).toHaveBeenCalledWith(
+        'authToken',
+        'jwt-token-123',
+        expect.objectContaining({ httpOnly: true }),
+      );
+      expect(authService.login).toHaveBeenCalled();
+    });
+
+    it('returns no body token but still sets the cookie when returnToken is omitted', async () => {
+      const { ctrl, res } = makeController();
+      const loginInput = { email: 'a@b.com', password: 'pw' };
+
+      const result = await ctrl.login(
+        workspace as any,
+        res as any,
+        loginInput as any,
+      );
+
+      expect(result).toBeUndefined();
+      expect(res.setCookie).toHaveBeenCalledTimes(1);
+    });
+
+    // Guards against an `!== undefined`-style bug: an explicit `false` must
+    // behave exactly like the omitted case (cookie set, no token in the body).
+    it('returns no body token but still sets the cookie when returnToken is false', async () => {
+      const { ctrl, res } = makeController();
+      const loginInput = {
+        email: 'a@b.com',
+        password: 'pw',
+        returnToken: false,
+      };
+
+      const result = await ctrl.login(
+        workspace as any,
+        res as any,
+        loginInput as any,
+      );
+
+      expect(result).toBeUndefined();
+      expect(res.setCookie).toHaveBeenCalledTimes(1);
+    });
+  });
 });

apps/server/src/core/auth/auth.controller.ts

@@ -97,6 +97,12 @@ export class AuthController {
         } else if (mfaResult.authToken) {
           // User doesn't have MFA and workspace doesn't require it
           this.setAuthCookie(res, mfaResult.authToken);
+          // Opt-in body token for native clients (Bearer auth). The response is
+          // wrapped by TransformHttpResponseInterceptor, so clients read it at
+          // `data.authToken`. Web clients omit returnToken and keep the cookie.
+          if (loginInput.returnToken) {
+            return { authToken: mfaResult.authToken };
+          }
           return;
         }
       }
@@ -104,6 +110,12 @@ export class AuthController {
 
     const authToken = await this.authService.login(loginInput, workspace.id);
     this.setAuthCookie(res, authToken);
+    // Opt-in body token for native clients (Bearer auth). The response is wrapped
+    // by TransformHttpResponseInterceptor, so clients read it at `data.authToken`.
+    // Web clients omit returnToken and keep using the httpOnly cookie only.
+    if (loginInput.returnToken) {
+      return { authToken };
+    }
   }
 
   @UseGuards(SetupGuard)

apps/server/src/core/auth/dto/login.dto.ts

@@ -1,4 +1,10 @@
-import { IsEmail, IsNotEmpty, IsString } from 'class-validator';
+import {
+  IsBoolean,
+  IsEmail,
+  IsNotEmpty,
+  IsOptional,
+  IsString,
+} from 'class-validator';
 
 export class LoginDto {
   @IsNotEmpty()
@@ -8,4 +14,13 @@ export class LoginDto {
   @IsNotEmpty()
   @IsString()
   password: string;
+
+  // When true, the access token is returned in the response body (in addition
+  // to the httpOnly cookie) so native/mobile clients can store it in
+  // Keychain/Keystore and send it as 'Authorization: Bearer'. Web clients omit
+  // this flag and keep using the cookie. Opt-in only: the token is never put in
+  // the body otherwise.
+  @IsOptional()
+  @IsBoolean()
+  returnToken?: boolean;
 }

apps/server/src/core/page/services/page.service.spec.ts

@@ -31,6 +31,102 @@ describe('PageService', () => {
     expect(service).toBeDefined();
   });
 
+  describe('update — title sync into collab doc (Bug 1)', () => {
+    const makeUpdateService = () => {
+      const pageRepo = {
+        updatePage: jest.fn().mockResolvedValue(undefined),
+        findById: jest.fn().mockResolvedValue({ id: 'page-1' }),
+      };
+      const generalQueue = { add: jest.fn().mockResolvedValue(undefined) };
+      const collaborationGateway = {
+        writePageTitle: jest.fn().mockResolvedValue(undefined),
+      };
+
+      const svc = new PageService(
+        pageRepo as any, // pageRepo
+        {} as any, // pagePermissionRepo
+        {} as any, // attachmentRepo
+        {} as any, // db
+        {} as any, // storageService
+        {} as any, // attachmentQueue
+        {} as any, // aiQueue
+        generalQueue as any, // generalQueue
+        {} as any, // eventEmitter
+        collaborationGateway as any, // collaborationGateway
+        {} as any, // watcherService
+        {} as any, // transclusionService
+      );
+
+      return { svc, pageRepo, collaborationGateway };
+    };
+
+    const basePage = (): Page =>
+      ({
+        id: 'page-1',
+        slugId: 'slug-1',
+        spaceId: 'space-1',
+        workspaceId: 'ws-1',
+        parentPageId: null,
+        title: 'Old Title',
+        icon: null,
+        contributorIds: [],
+      }) as any;
+
+    const user = { id: 'u1' } as any;
+
+    it('writes the new title into the collab doc when the title actually changed', async () => {
+      const { svc, collaborationGateway } = makeUpdateService();
+
+      await svc.update(basePage(), { title: 'New Title' } as any, user);
+
+      // Must use the Redis-independent writePageTitle (direct
+      // openDirectConnection), NOT handleYjsEvent which no-ops without Redis.
+      expect(collaborationGateway.writePageTitle).toHaveBeenCalledTimes(1);
+      expect(collaborationGateway.writePageTitle).toHaveBeenCalledWith(
+        'page-1',
+        'New Title',
+        expect.objectContaining({ user }),
+      );
+    });
+
+    it('threads agent provenance into the collab title write', async () => {
+      const { svc, collaborationGateway } = makeUpdateService();
+
+      await svc.update(basePage(), { title: 'New Title' } as any, user, {
+        actor: 'agent',
+        aiChatId: 'chat-1',
+      } as any);
+
+      expect(collaborationGateway.writePageTitle).toHaveBeenCalledWith(
+        'page-1',
+        'New Title',
+        expect.objectContaining({ actor: 'agent', aiChatId: 'chat-1' }),
+      );
+    });
+
+    it('does NOT write into the collab doc when the title is unchanged', async () => {
+      const { svc, collaborationGateway } = makeUpdateService();
+
+      // Same title -> titleChanged is false; an icon-only change must not fire
+      // the title sync.
+      await svc.update(
+        basePage(),
+        { title: 'Old Title', icon: '📄' } as any,
+        user,
+      );
+
+      expect(collaborationGateway.writePageTitle).not.toHaveBeenCalled();
+    });
+
+    it('does NOT write into the collab doc when the DTO omits the title', async () => {
+      const { svc, collaborationGateway } = makeUpdateService();
+
+      await svc.update(basePage(), { icon: '📄' } as any, user);
+
+      expect(collaborationGateway.writePageTitle).not.toHaveBeenCalled();
+    });
+  });
+
   describe('movePage cycle guard (#67)', () => {
     // A valid fractional-indexing key — movePage validates `position` by feeding
     // it to generateJitteredKeyBetween(position, null) before anything else.