fix(client): add /l vanity route to SW denylist; name failed offline steps (F2, F3)

F2: navigateFallbackDenylist was missing the server's `l/:alias` vanity
short-link, so a top-nav to /l/<alias> after SW registration got the
index.html app shell (which has no /l route) and dead-ended on Error404
instead of the server's 302 redirect. Add /^\/l(\/|$)/ mirroring main.ts.

F3: the partial-failure branch of "make page available offline" showed a
bare generic toast; include result.failed step labels in the message per
AGENTS.md (errors must be specific), matching the catch-branch below it.

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
 
@@ -132,11 +145,12 @@ MCP_DOCMOST_PASSWORD=
 # NEVER set is_agent on a human or shared account — every action by that account
 # (including normal human edits) would then be mis-attributed as AI.
 
-# Agent-roles catalog source: an http(s):// base URL => the catalog is fetched
-# remotely (e.g. the raw GitHub base URL of the catalog repo); any other value
-# => a local filesystem directory. Empty (default) => the in-repo
-# ./agent-roles-catalog folder (dev). Used by the admin "import role from
-# catalog" feature only.
+# Agent-roles catalog source: an http(s):// base URL to the catalog's raw files
+# (the server appends /index.json and /bundles/<id>/<lang>.json). This value is
+# baked into the Docker image at build time per branch (see the Dockerfile ARG
+# AI_AGENT_ROLES_CATALOG_URL and the CI build-args). Set it here only to point a
+# local/non-Docker run at a catalog; if unset, the "import role from catalog"
+# admin feature is unavailable. Local-filesystem sources are no longer supported.
 # AI_AGENT_ROLES_CATALOG_URL=
 
 # Per-embedding-call timeout in milliseconds for the RAG indexer.

.github/workflows/develop.yml

@@ -52,6 +52,7 @@ jobs:
           platforms: linux/amd64
           build-args: |
             APP_VERSION=${{ steps.version.outputs.value }}
+            AI_AGENT_ROLES_CATALOG_URL=https://raw.githubusercontent.com/vvzvlad/gitmost/develop/agent-roles-catalog
           push: true
           tags: ${{ env.IMAGE }}:develop
           cache-from: type=gha,scope=develop-amd64

.github/workflows/release.yml

@@ -17,6 +17,7 @@ permissions:
 env:
   VERSION: ${{ inputs.version || github.ref_name }}
   IMAGE: ghcr.io/vvzvlad/gitmost
+  AI_AGENT_ROLES_CATALOG_URL: https://raw.githubusercontent.com/vvzvlad/gitmost/main/agent-roles-catalog
 
 jobs:
   # Run the reusable test suite first so a failing test blocks the image build.
@@ -57,6 +58,7 @@ jobs:
           platforms: ${{ matrix.platform }}
           build-args: |
             APP_VERSION=${{ env.VERSION }}
+            AI_AGENT_ROLES_CATALOG_URL=${{ env.AI_AGENT_ROLES_CATALOG_URL }}
           outputs: type=image,name=${{ env.IMAGE }},push-by-digest=true,name-canonical=true,push=true
           cache-from: type=gha,scope=${{ matrix.suffix }}
           cache-to: type=gha,scope=${{ matrix.suffix }},mode=max,ignore-error=true
@@ -85,6 +87,7 @@ jobs:
           platforms: ${{ matrix.platform }}
           build-args: |
             APP_VERSION=${{ env.VERSION }}
+            AI_AGENT_ROLES_CATALOG_URL=${{ env.AI_AGENT_ROLES_CATALOG_URL }}
           push: false
           tags: |
             ${{ env.IMAGE }}:latest

.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

AGENTS.md

@@ -254,7 +254,7 @@ The API server is a Fastify app with a global `/api` prefix (`main.ts` excludes
 - **Redis** backs caching, the BullMQ queues, the WebSocket Socket.IO adapter, and collaboration sync.
 
 ### The two AI subsystems (the main fork additions)
-1. **Embedded MCP server** (`integrations/mcp/` + `packages/mcp`). The standalone `@docmost/mcp` server (38 agent-native tools: per-block patch/insert/delete by id, scripted `(doc)=>doc` transforms with dry-run diff, table editing, version diff/restore, comments, images, shares) is bundled and served over HTTP at `/mcp`. It writes through Docmost's real-time-collaboration layer so concurrent human edits aren't clobbered. Each request authenticates **per-user** via the `Authorization` header — either HTTP Basic (`base64(email:password)`, the user's own Docmost login, validated through `AuthService`) or a Bearer access JWT (the user's `authToken`) — and the session acts under that user's permissions. `MCP_DOCMOST_EMAIL` / `MCP_DOCMOST_PASSWORD` are an **optional service-account fallback**, used only when a request carries neither Basic nor Bearer credentials (back-compat for CI/scripts). An admin enables MCP with a workspace toggle (Workspace settings → AI). Optionally protected by a shared `MCP_TOKEN`: when set, every `/mcp` request must carry a matching `X-MCP-Token` header (its own header, separate from `Authorization`, which now carries the per-user Basic/Bearer credentials). Note: this changed from the older `Authorization: Bearer <MCP_TOKEN>` scheme — see `.env.example` and the CHANGELOG Breaking Changes entry.
+1. **Embedded MCP server** (`integrations/mcp/` + `packages/mcp`). The standalone `@docmost/mcp` server (39 agent-native tools: per-block patch/insert/delete by id, scripted `(doc)=>doc` transforms with dry-run diff, table editing, version diff/restore, comments, images, shares) is bundled and served over HTTP at `/mcp`. It writes through Docmost's real-time-collaboration layer so concurrent human edits aren't clobbered. Each request authenticates **per-user** via the `Authorization` header — either HTTP Basic (`base64(email:password)`, the user's own Docmost login, validated through `AuthService`) or a Bearer access JWT (the user's `authToken`) — and the session acts under that user's permissions. `MCP_DOCMOST_EMAIL` / `MCP_DOCMOST_PASSWORD` are an **optional service-account fallback**, used only when a request carries neither Basic nor Bearer credentials (back-compat for CI/scripts). An admin enables MCP with a workspace toggle (Workspace settings → AI). Optionally protected by a shared `MCP_TOKEN`: when set, every `/mcp` request must carry a matching `X-MCP-Token` header (its own header, separate from `Authorization`, which now carries the per-user Basic/Bearer credentials). Note: this changed from the older `Authorization: Bearer <MCP_TOKEN>` scheme — see `.env.example` and the CHANGELOG Breaking Changes entry.
 2. **AI agent chat** (`core/ai-chat/` server + `apps/client/src/features/ai-chat/` client). A built-in agent over the wiki using the Vercel **AI SDK** (`ai`, `@ai-sdk/*`) against any OpenAI-compatible provider configured per workspace (`integrations/ai/` — credentials encrypted at rest via `integrations/crypto`, stored in `ai_provider_credentials`). Key pieces:
    - `core/ai-chat/tools/` — the agent's ~40 read+write tools. Every tool runs under the **calling user's** CASL permissions via a per-user loopback access token (`docmost-client.loader.ts`), so the agent can never exceed what the user could do. Only **reversible** operations are exposed (page history + trash; no permanent delete). Agent edits get an "AI agent" provenance badge in page history (`20260616T130000-agent-provenance` migration).
    - `core/ai-chat/embedding/` — RAG indexer + a BullMQ consumer on `AI_QUEUE` that embeds pages into `page_embeddings` (vector search), complementing Postgres full-text search. Pages are (re)indexed on edit; `AI_EMBEDDING_TIMEOUT_MS` bounds a hung embeddings endpoint.

CHANGELOG.md

@@ -37,13 +37,81 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   admin endpoints — `POST /ai-chat/roles/catalog` (browse bundles),
   `/catalog/bundle` (read one bundle's roles), `/import`, and
   `/update-from-catalog` — and a new `source` column linking a role to its
-  catalog slug/language/version. The catalog source is configurable via the new
-  `AI_AGENT_ROLES_CATALOG_URL` env var (an `http(s)://` base URL fetches it
-  remotely; otherwise a local directory; empty defaults to the in-repo
-  `agent-roles-catalog/` folder — see `.env.example`). (#222)
+  catalog slug/language/version. The catalog source is configured via the
+  `AI_AGENT_ROLES_CATALOG_URL` env var — an `http(s)://` base URL to the
+  catalog's raw files; the image ships a per-branch default baked in CI, and it
+  can be overridden at runtime via the env var (see `.env.example`). (#222)
+- **Author footnotes inline from an agent, and deterministic server-side footnote
+  canonicalization on every non-editor write path.** A new MCP `insert_footnote`
+  tool places a footnote at a body anchor by content only — the agent supplies
+  WHERE (anchor text) and WHAT (markdown); the number and the bottom
+  `footnotesList` are derived server-side, so an agent can never assign a number,
+  edit the list, or desync, and a same-content note reuses one definition. Under
+  the hood, the editor's footnote-integrity invariant (one trailing list,
+  numbering by first reference, no orphans/duplicates, no raw `[^id]`) is now
+  enforced as a pure `canonicalizeFootnotes(doc)` on the FULL-document write paths
+  that bypass the editor's plugins: server markdown/HTML import, `PageService`
+  create and full-document (`replace`) updates, the client markdown paste, and the
+  MCP markdown page-import / `update_page` (markdown) / `update_page_json` /
+  `docmost_transform` / `insert_footnote` / `copy_page_content` paths. It is
+  idempotent (a no-op once canonical) and is deliberately NOT applied to
+  append/prepend fragments, nor to COMMENT bodies — a comment may legitimately
+  contain a standalone footnote definition, which canonicalization would drop.
+  (#228)
+
+### Changed
+
+- **Enabling a public share no longer auto-shares the whole sub-tree.** Turning
+  a page "Shared to web" now defaults to the page alone; descendant pages become
+  public only when you explicitly turn on the dedicated "Include sub-pages"
+  toggle. Previously the create call defaulted to including sub-pages, silently
+  exposing every child of a freshly shared page. (#216)
+
+- **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`.
+
+### Changed
+
+- **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
 
+- **Internal links in exported Markdown no longer lose their visible text.** A
+  link whose target page name had no file extension (e.g. a bare title) was
+  collapsed to empty text during export, producing an unclickable, label-less
+  link; the page name is now preserved. (#204)
+- **Deep pages no longer render a blank breadcrumb while the sidebar tree loads.**
+  The breadcrumb now falls back to the page's own ancestor chain (fetched
+  independently of the lazily-built sidebar tree) so a deep page resolves its
+  trail immediately; navigating away no longer leaves the previously-viewed
+  page's breadcrumb showing until the new one resolves. (#206, #218)
+- **Pasted GitHub-style callouts (`> [!NOTE]` …) now convert to real callouts.**
+  GitHub admonition blocks pasted as Markdown are recognized and rendered as
+  callout blocks instead of plain block-quotes. (#192)
+- **The editor stays read-only until collaboration has synced.** While a page is
+  connecting, the body is shown as a non-editable static view with a
+  "Connecting… (read-only)" banner, so edits typed before the document finishes
+  syncing can no longer be silently dropped. (#218)
 - **A shared page now keeps EXACTLY ONE custom address (`/l/:alias`).** Editing a
   page's vanity slug previously inserted a second `share_aliases` row instead of
   renaming the existing one, leaving the old `/l/<old>` link live forever and
@@ -55,6 +123,27 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   page), so any previously-live duplicate `/l/<old>` link begins returning the
   generic 404 after upgrade — intended, but not undoable by `down()`. (#226,
   #227)
+- **Typing a custom address already used by another page no longer looks like a
+  dead end.** The share modal previously flagged such a name with a red "This
+  address is already in use" error, hiding the fact that saving offers to MOVE
+  the address to the current page. The field now shows an informational hint —
+  "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)
+
+### Security
+
+- **The anonymous public-share page payload is trimmed to an explicit allowlist.**
+  The `/shares/page-info` route (the only unauthenticated path serializing a
+  page + its share) now returns only the fields the public renderer needs;
+  internal metadata — creator/last-updater/contributor ids, space/workspace ids,
+  AI/source bookkeeping, lock/template flags, parent/position and raw timestamps
+  — is no longer exposed to anonymous viewers. (#218)
+- **A forged or mismatched share id can no longer render a page off its slug
+  alone.** When the public URL carries a share id/key, the page must be reachable
+  through that exact share (its own share or an ancestor `includeSubPages`
+  share); any other value now returns the generic "not found" instead of
+  serving the page. (#218)
 
 ## [0.94.0] - 2026-06-26
 
@@ -134,6 +223,13 @@ per-workspace rolling-day token budget.
   applies it through the existing `/pages/update` route — reflecting it in the
   title field and broadcasting to other clients. Gated by the `settings.ai.generative`
   flag and throttled per user. (#199)
+- **AI chat: header button auto-opens the chat bound to the current document.**
+  Clicking the AI-chat button in the header while viewing a page now reopens the
+  latest chat tied to that document instead of whatever chat was last active,
+  reusing the existing `ai_chats.page_id` provenance (no migration). The newest
+  chat you created on the page wins; with no bound chat — or off a page, or if
+  the lookup fails — it falls soft to a fresh chat and keeps the current
+  selection otherwise. (#191)
 
 ### Changed
 

Dockerfile

@@ -23,6 +23,11 @@ RUN apt-get update \
 
 WORKDIR /app
 
+# Agent-roles catalog base URL: per-branch default set at build time (CI);
+# overridable at runtime via the AI_AGENT_ROLES_CATALOG_URL env var.
+ARG AI_AGENT_ROLES_CATALOG_URL=""
+ENV AI_AGENT_ROLES_CATALOG_URL=$AI_AGENT_ROLES_CATALOG_URL
+
 # Copy apps
 COPY --from=builder /app/apps/server/dist /app/apps/server/dist
 COPY --from=builder /app/apps/client/dist /app/apps/client/dist

README.md

@@ -34,7 +34,7 @@ The goal of the fork is a **100% open, AGPL-only build with no Enterprise-Editio
 | --- | --- |
 | **EE code removed** | Stripped all client and server Enterprise-Edition code; ships as a clean community/AGPL build with no license checks. |
 | **Comment resolution** | Re-implemented from scratch as a community feature (resolve / re-open with Open/Resolved tabs). No EE code reused, available to anyone who can comment. |
-| **Embedded MCP server** | A community MCP server (`@docmost/mcp`, 38 tools) is served over HTTP at `/mcp` — no enterprise license required. Replaces the removed license-gated EE MCP. |
+| **Embedded MCP server** | A community MCP server (`@docmost/mcp`, 39 tools) is served over HTTP at `/mcp` — no enterprise license required. Replaces the removed license-gated EE MCP. |
 | **AI agent chat** | Built-in AI agent chat over your wiki, written from scratch as a community feature — no enterprise license. The agent reads and edits pages on your behalf (scoped to your permissions), with full-text + vector (RAG) search and optional web access via external MCP servers. |
 | **Rebranding** | App logo / name changed from *Docmost* to *Gitmost*. |
 | **Compact page tree** | Default page-tree indentation reduced from 16px to 8px per nesting level. |
@@ -44,7 +44,7 @@ The goal of the fork is a **100% open, AGPL-only build with no Enterprise-Editio
 ### Embedded MCP server
 
 Gitmost has **our own MCP server** — [docmost-mcp](https://github.com/vvzvlad/docmost-mcp),
-which we wrote — **built directly into the app** and served at `/mcp`. It exposes **38
+which we wrote — **built directly into the app** and served at `/mcp`. It exposes **39
 agent-native tools**: surgical per-block edits (patch / insert / delete by id),
 structure-preserving find/replace, scripted `(doc) => doc` transforms with a dry-run diff,
 structured table editing, version history with diff / restore, comments, images and share
@@ -60,7 +60,7 @@ every little fix. And it needs no enterprise license.
 | | **Gitmost `/mcp` (our docmost-mcp)** | Docmost's built-in MCP |
 | --- | :---: | :---: |
 | **Enterprise license** | Not required | Required |
-| **Tools** | 38, agent-native | Coarse (read Markdown, page CRUD, replace whole page) |
+| **Tools** | 39, agent-native | Coarse (read Markdown, page CRUD, replace whole page) |
 | **Per-block edits / find-replace / scripted transforms** | ✅ | — |
 | **Structured table editing, version diff / restore** | ✅ | — |
 | **Comments, images, share links** | ✅ | — |

README.ru.md

@@ -33,7 +33,7 @@
 | --- | --- |
 | **Удалён EE-код** | Вырезан весь код Enterprise-редакции на клиенте и сервере; это чистая community/AGPL-сборка без лицензионных проверок. |
 | **Резолв комментариев** | Переписан с нуля как community-функция (резолв / переоткрытие с вкладками «Открытые» / «Решённые»). EE-код не используется, доступно любому, кто может комментировать. |
-| **Встроенный MCP-сервер** | Community MCP-сервер (`@docmost/mcp`, 38 инструментов) отдаётся по HTTP на `/mcp` — без enterprise-лицензии. Заменяет удалённый лицензируемый EE MCP. |
+| **Встроенный MCP-сервер** | Community MCP-сервер (`@docmost/mcp`, 39 инструментов) отдаётся по HTTP на `/mcp` — без enterprise-лицензии. Заменяет удалённый лицензируемый EE MCP. |
 | **Чат с AI-агентом** | Встроенный чат с AI-агентом по содержимому вики, написанный с нуля как community-функция — без enterprise-лицензии. Агент читает и редактирует страницы от вашего имени (в рамках ваших прав), с полнотекстовым + векторным (RAG) поиском и опциональным доступом в интернет через внешние MCP-серверы. |
 | **Ребрендинг** | Логотип / название приложения изменены с *Docmost* на *Gitmost*. |
 | **Компактное дерево страниц** | Отступ дерева страниц по умолчанию уменьшен с 16px до 8px на уровень вложенности. |
@@ -44,7 +44,7 @@
 
 В Gitmost есть **наш собственный MCP-сервер** — [docmost-mcp](https://github.com/vvzvlad/docmost-mcp),
 который мы написали сами, — **встроенный прямо в приложение** и доступный на `/mcp`. Он даёт
-**38 agent-native инструментов**: точечное редактирование по блокам (patch / insert / delete
+**39 agent-native инструментов**: точечное редактирование по блокам (patch / insert / delete
 по id), find/replace с сохранением структуры, скриптовые трансформации `(doc) => doc` с
 предпросмотром диффа, структурное редактирование таблиц, история версий с диффом /
 восстановлением, комментарии, изображения и ссылки на шаринг — всё применяется через слой
@@ -60,7 +60,7 @@ real-time-коллаборации Docmost, поэтому запись нико
 | | **`/mcp` в Gitmost (наш docmost-mcp)** | Родной MCP у Docmost |
 | --- | :---: | :---: |
 | **Enterprise-лицензия** | Не нужна | Нужна |
-| **Инструменты** | 38, agent-native | Примитивные (Markdown, CRUD страниц, замена целиком) |
+| **Инструменты** | 39, agent-native | Примитивные (Markdown, CRUD страниц, замена целиком) |
 | **Правки по блокам / find-replace / скриптовые трансформации** | ✅ | — |
 | **Структурное редактирование таблиц, дифф / восстановление версий** | ✅ | — |
 | **Комментарии, изображения, ссылки на шаринг** | ✅ | — |

agent-roles-catalog/README.md

@@ -16,6 +16,7 @@ agent-roles-catalog/
       <lang>.json             # one file per declared language (e.g. ru.json, en.json)
   scripts/
     check.mjs                 # validates the catalog (no dependencies)
+    content-hashes.json       # check artifact: per-role content-hash lock (NOT served)
   package.json                # defines the `check` script
   README.md
 ```
@@ -23,27 +24,27 @@ agent-roles-catalog/
 Currently shipped bundles:
 
 - `editorial` — the editorial suite (structural-editor, line-editor,
-  copy-editor, fact-checker, proofreader, narrator), languages `ru`, `en`.
+  fact-checker, proofreader, narrator), languages `ru`, `en`.
 - `research` — a single `researcher` role, languages `ru`, `en`.
 
 ## How it's served
 
 The server does not bundle this data; it reads it at request time from a single
 configured location, the `AI_AGENT_ROLES_CATALOG_URL` env var
-(`EnvironmentService.getAiAgentRolesCatalogSource()`). The value selects one of
-three sources:
+(`EnvironmentService.getAiAgentRolesCatalogSource()`), an `http(s)://` base URL
+to the catalog's raw files. The server fetches `<base>/index.json` for the
+manifest and `<base>/bundles/<bundle-id>/<lang>.json` for each opened bundle
+file (REMOTE only).
 
-- **`http(s)://…`** — a REMOTE base URL. The server fetches `<base>/index.json`
-  for the manifest and `<base>/bundles/<bundle-id>/<lang>.json` for each opened
-  bundle file (e.g. the raw GitHub base of the catalog repo in production).
-- **any other non-empty value** — a LOCAL filesystem directory; the same
-  `index.json` / `bundles/<id>/<lang>.json` paths are read from disk.
-- **empty / unset** (the default) — the in-repo `agent-roles-catalog/` folder
-  (this directory), i.e. local dev reads these files directly.
+That base URL is provided as a per-branch default in the Docker image (set in
+CI: a `develop` build points at the `develop` raw URL, a release build at the
+`main` raw URL) and can be overridden at runtime via the
+`AI_AGENT_ROLES_CATALOG_URL` env var. Local-filesystem sources are no longer
+supported; if the value is unset the catalog is unavailable.
 
-In every case the layout below is what the server expects, and the fetched JSON
-is re-validated server-side (the catalog is treated as untrusted input). See
-`.env.example` for the variable and the CHANGELOG for the rollout.
+The fetched JSON is re-validated server-side (the catalog is treated as
+untrusted input). See `.env.example` for the variable and the CHANGELOG for the
+rollout.
 
 ## `index.json` schema
 
@@ -133,7 +134,10 @@ bundle. A slug appears once per language file of its bundle (same slug in
 ### Change a role's content
 
 Edit the role in the relevant `<lang>.json` file(s) and **bump that role's
-`version`** in `index.json`.
+`version`** in `index.json`. Then run `node scripts/check.mjs --update-hashes`
+to refresh the content-hash lock (`scripts/content-hashes.json`). `check.mjs`
+now **fails if a role's content changed but its `version` was not bumped**, so
+this step is mandatory — the lock can only be refreshed after the bump.
 
 ## Validating
 
@@ -147,3 +151,43 @@ It fails (exit code 1) if any slug is duplicated across the catalog, if a
 bundle's index `roles[]` don't match the slugs present in each language file, if
 a declared language file is missing, or if any role is missing a required field
 (`slug`, `name`, `instructions`). It prints `OK` on success.
+
+### Content-hash guard
+
+`check.mjs` also guards against changing a role's content without bumping its
+`version`. It keeps a lockfile, `scripts/content-hashes.json`, mapping each role
+`slug` to `{ version, hash }`, where `hash` is a SHA-256 over the role's
+content fields (`emoji`, `autoStart`, `name`, `description`, `instructions`,
+`launchMessage`) across all of its language files, in a deterministic canonical
+form. This lockfile is a **check artifact only** — the server fetches only
+`index.json` and the bundle `<lang>.json` files, never this file, so it has no
+effect on the served catalog or its schema.
+
+On a normal run, for every role the check recomputes the hash and compares it
+against the lock:
+
+- content unchanged and versions agree → OK;
+- content changed but `version` not bumped above the lock → **error** asking you
+  to bump and refresh;
+- content changed and `version` bumped → **error** asking you to record it by
+  refreshing the lock;
+- role missing from the lock, or a lock entry for a role that no longer exists →
+  **error** asking you to refresh.
+
+Refresh the lock with:
+
+```sh
+node scripts/check.mjs --update-hashes   # alias: --fix
+```
+
+This recomputes the lock from the current catalog, prunes entries for removed
+roles, and prints what changed — but it **refuses to write** (exit 1) if any
+role's content changed while its `index.json` version was not bumped, so the
+version bump is always enforced first. The check also requires every
+`index.json` role to carry a finite numeric `version` (the server requires the
+same).
+
+Known, accepted limitation: a deliberate prune-then-readd of a slug (remove the
+role and run `--update-hashes`, then re-add it with changed content at the same
+version) is **not** caught, because a brand-new slug has no lock baseline to
+enforce a bump against.

agent-roles-catalog/index.json

@@ -5,16 +5,15 @@
       "id": "editorial",
       "name": { "ru": "Редакторский набор", "en": "Editorial suite" },
       "description": {
-        "ru": "Полный цикл редактуры статьи: структура, стиль, грамматика, факты, корректура и нарратив.",
-        "en": "The full article-editing cycle: structure, style, grammar, facts, proofreading, and narrative."
+        "ru": "Полный цикл редактуры статьи: структура, стиль, корректура, факты и нарратив.",
+        "en": "The full article-editing cycle: structure, style, copyediting, facts, and narrative."
       },
       "languages": ["ru", "en"],
       "roles": [
-        { "slug": "structural-editor", "version": 1 },
-        { "slug": "line-editor", "version": 1 },
-        { "slug": "copy-editor", "version": 1 },
-        { "slug": "fact-checker", "version": 1 },
-        { "slug": "proofreader", "version": 1 },
+        { "slug": "structural-editor", "version": 2 },
+        { "slug": "line-editor", "version": 2 },
+        { "slug": "fact-checker", "version": 3 },
+        { "slug": "proofreader", "version": 3 },
         { "slug": "narrator", "version": 1 }
       ]
     },

agent-roles-catalog/scripts/check.mjs

@@ -4,13 +4,23 @@
 // between a bundle's index roles[] and the slugs present in each language
 // file, a missing declared language file, or a role missing required fields.
 
-import { readFileSync, existsSync } from "node:fs";
+import { readFileSync, writeFileSync, existsSync } from "node:fs";
+import { createHash } from "node:crypto";
 import { fileURLToPath } from "node:url";
 import { dirname, join } from "node:path";
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const catalogDir = join(__dirname, "..");
 
+// `--update-hashes` (alias `--fix`) recomputes the content-hash lockfile from
+// the current catalog instead of just validating against it.
+const updateHashes =
+  process.argv.includes("--update-hashes") || process.argv.includes("--fix");
+
+// The content-hash lockfile lives under scripts/ and is a CHECK ARTIFACT only:
+// the server never fetches it, so it has zero impact on the served schema.
+const lockPath = join(__dirname, "content-hashes.json");
+
 const errors = [];
 
 function readJson(path) {
@@ -56,6 +66,17 @@ for (const bundle of bundles) {
     errors.push(`Bundle "${bundleId}" index.json roles[] contains duplicate slugs`);
   }
 
+  // Each index role must carry a finite numeric "version". The server requires
+  // this (see ai-agent-roles-catalog.provider.ts), and the content-hash guard
+  // below relies on it for the bump comparison, so enforce it here too.
+  for (const r of bundle.roles || []) {
+    if (typeof r.version !== "number" || !Number.isFinite(r.version)) {
+      errors.push(
+        `Bundle "${bundleId}" index.json role "${r.slug}" is missing a numeric "version"`
+      );
+    }
+  }
+
   const languages = Array.isArray(bundle.languages) ? bundle.languages : [];
   if (languages.length === 0) {
     errors.push(`Bundle "${bundleId}" declares no languages`);
@@ -121,6 +142,208 @@ for (const bundle of bundles) {
   }
 }
 
+// ---------------------------------------------------------------------------
+// Content-hash guard: detect "content changed without a version bump".
+//
+// check.mjs cannot use git history, so we maintain a lockfile
+// (scripts/content-hashes.json) mapping each role slug to its recorded
+// { version, hash }. On every run we recompute each role's content hash and
+// compare it against the lock; a content change is only allowed once the role's
+// version in index.json has been bumped and the lock refreshed.
+//
+// Known, accepted limitation: a deliberate prune-then-readd of a slug (remove
+// the role and run --update-hashes, then re-add it with changed content at the
+// same version) is NOT caught, because a brand-new slug has no lock baseline to
+// enforce a bump against. We document this rather than building tombstones.
+// ---------------------------------------------------------------------------
+
+// Content fields hashed for each role, in a fixed canonical order. `slug` is
+// identity (not content) and `version` lives in index.json, so neither is here.
+// `modelConfig` (an OPTIONAL role field the server also serves) is intentionally
+// EXCLUDED: no shipped role uses it today, and being an object it would need a
+// deterministic deep canonicalization (recursive key sort) before hashing —
+// otherwise JSON.stringify key-order would make the hash non-deterministic. If a
+// role ever gains a `modelConfig`, add it here WITH such canonicalization so a
+// change to it is still caught by the bump guard.
+const CONTENT_FIELDS = [
+  "emoji",
+  "autoStart",
+  "name",
+  "description",
+  "instructions",
+  "launchMessage",
+];
+
+// Build a map of slug -> { version, langRoles: { lang: roleObject } } from the
+// current catalog so we can compute hashes and read index versions.
+function collectCatalogRoles() {
+  const out = new Map(); // slug -> { version, langRoles: Map<lang, role> }
+  for (const bundle of bundles) {
+    const bundleId = bundle.id;
+    if (!bundleId) continue;
+    const languages = Array.isArray(bundle.languages) ? bundle.languages : [];
+    for (const r of bundle.roles || []) {
+      if (!r || !r.slug) continue;
+      if (!out.has(r.slug)) {
+        out.set(r.slug, { version: r.version, langRoles: new Map() });
+      } else {
+        // Same slug declared twice in index.json roles[]; already flagged above.
+        out.get(r.slug).version = r.version;
+      }
+    }
+    for (const lang of languages) {
+      const langPath = join(catalogDir, "bundles", bundleId, `${lang}.json`);
+      if (!existsSync(langPath)) continue;
+      const langFile = readJson(langPath);
+      if (!langFile) continue;
+      const roles = Array.isArray(langFile.roles) ? langFile.roles : [];
+      for (const role of roles) {
+        if (!role || !role.slug) continue;
+        const entry = out.get(role.slug);
+        if (!entry) continue; // role not declared in index.json; flagged above.
+        entry.langRoles.set(lang, role);
+      }
+    }
+  }
+  return out;
+}
+
+// Deterministic content hash for a role: languages sorted ascending, each
+// language's content fields taken in CONTENT_FIELDS order (null when absent).
+function contentHash(langRoles) {
+  const langs = [...langRoles.keys()].sort();
+  const canonical = langs.map((lang) => {
+    const role = langRoles.get(lang);
+    const fields = {};
+    for (const field of CONTENT_FIELDS) {
+      fields[field] = role && role[field] != null ? role[field] : null;
+    }
+    return [lang, fields];
+  });
+  return createHash("sha256").update(JSON.stringify(canonical)).digest("hex");
+}
+
+// Compute current { version, hash } for every catalog role.
+const catalogRoles = collectCatalogRoles();
+const current = new Map(); // slug -> { version, hash }
+for (const [slug, entry] of catalogRoles) {
+  current.set(slug, {
+    version: entry.version,
+    hash: contentHash(entry.langRoles),
+  });
+}
+
+// Load the existing lock (may be absent on first run).
+let lock = {};
+if (existsSync(lockPath)) {
+  const parsed = readJson(lockPath);
+  if (parsed && typeof parsed === "object") lock = parsed;
+}
+
+if (updateHashes) {
+  // Refresh the lock from the current catalog, but refuse to write if any role's
+  // content changed without its version being bumped above the existing lock.
+  const blockers = [];
+  for (const [slug, cur] of current) {
+    const prev = lock[slug];
+    if (!prev) continue; // new role; nothing to enforce a bump against.
+    if (cur.hash === prev.hash) continue; // content unchanged.
+    // Defense-in-depth: a non-numeric version must never pass the bump check via
+    // `undefined <= N` (which is false). The standard checks already flag a
+    // missing numeric version, but guard here too before comparing.
+    if (typeof cur.version !== "number" || !Number.isFinite(cur.version)) {
+      blockers.push(
+        `role "${slug}" content changed but its index.json "version" is missing or not numeric; set a numeric "version" before refreshing the lock`
+      );
+    } else if (cur.version <= prev.version) {
+      blockers.push(
+        `role "${slug}" content changed but its version was not bumped (still ${prev.version}); bump "version" in index.json before refreshing the lock`
+      );
+    }
+  }
+  // Still honor the standard checks before allowing a write.
+  if (errors.length > 0) {
+    console.error("Catalog check FAILED:");
+    for (const e of errors) console.error(`  - ${e}`);
+    process.exit(1);
+  }
+  if (blockers.length > 0) {
+    console.error("Refusing to update content-hash lock:");
+    for (const b of blockers) console.error(`  - ${b}`);
+    process.exit(1);
+  }
+
+  // Compute the change summary relative to the old lock, pruning removed slugs.
+  const newLock = {};
+  const added = [];
+  const changed = [];
+  const removed = [];
+  for (const [slug, cur] of [...current].sort((a, b) => a[0].localeCompare(b[0]))) {
+    newLock[slug] = { version: cur.version, hash: cur.hash };
+    const prev = lock[slug];
+    if (!prev) added.push(slug);
+    else if (prev.hash !== cur.hash || prev.version !== cur.version) changed.push(slug);
+  }
+  for (const slug of Object.keys(lock)) {
+    if (!current.has(slug)) removed.push(slug);
+  }
+  writeFileSync(lockPath, JSON.stringify(newLock, null, 2) + "\n");
+  console.log(`Wrote ${lockPath}`);
+  if (added.length) console.log(`  added:   ${added.join(", ")}`);
+  if (changed.length) console.log(`  updated: ${changed.join(", ")}`);
+  if (removed.length) console.log(`  pruned:  ${removed.join(", ")}`);
+  if (!added.length && !changed.length && !removed.length) {
+    console.log("  (no changes; lock already up to date)");
+  }
+  console.log("OK");
+  process.exit(0);
+}
+
+// Normal run: validate current content against the lock.
+for (const [slug, cur] of current) {
+  const prev = lock[slug];
+  if (!prev) {
+    errors.push(
+      `role "${slug}" is not recorded in the content-hash lock; run: node scripts/check.mjs --update-hashes`
+    );
+    continue;
+  }
+  if (cur.hash === prev.hash) {
+    // Content unchanged; the lock version must still agree with index.json.
+    if (cur.version !== prev.version) {
+      errors.push(
+        `role "${slug}" content is unchanged but its index.json version (${cur.version}) differs from the lock (${prev.version}); run: node scripts/check.mjs --update-hashes`
+      );
+    }
+    continue;
+  }
+  // Content changed.
+  // Defense-in-depth: treat a non-numeric version as an error before the `<=`
+  // comparison, so a missing version can never silently pass the bump check
+  // (and we avoid a misleading "version bumped to undefined" message).
+  if (typeof cur.version !== "number" || !Number.isFinite(cur.version)) {
+    errors.push(
+      `role "${slug}" content changed but its index.json "version" is missing or not numeric; set a numeric "version", then run: node scripts/check.mjs --update-hashes`
+    );
+  } else if (cur.version <= prev.version) {
+    errors.push(
+      `role "${slug}" content changed but its version was not bumped (still ${prev.version}); bump "version" in index.json, then run: node scripts/check.mjs --update-hashes`
+    );
+  } else {
+    errors.push(
+      `role "${slug}" content changed and version bumped to ${cur.version}; record it by running: node scripts/check.mjs --update-hashes`
+    );
+  }
+}
+// Lock entries for slugs that no longer exist in the catalog.
+for (const slug of Object.keys(lock)) {
+  if (!current.has(slug)) {
+    errors.push(
+      `content-hash lock has entry for unknown role "${slug}" (no longer in the catalog); run: node scripts/check.mjs --update-hashes`
+    );
+  }
+}
+
 if (errors.length > 0) {
   console.error("Catalog check FAILED:");
   for (const e of errors) console.error(`  - ${e}`);

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

@@ -0,0 +1,26 @@
+{
+  "fact-checker": {
+    "version": 3,
+    "hash": "a94931fbd20272570a588c72159ac9e48a89c99bd8f718449cda5e7ca4280fdf"
+  },
+  "line-editor": {
+    "version": 2,
+    "hash": "cca324110dc6f96d2a8a239a2fb95b0ba09fad5806c9b6090a3c210ea7883ceb"
+  },
+  "narrator": {
+    "version": 1,
+    "hash": "36b38785fea6ae1c70bf6fb6b29ae5278bb86e389e61f7b9736675a589fa434c"
+  },
+  "proofreader": {
+    "version": 3,
+    "hash": "a36047c5cab837b2a727f63d4ddafc269b1fc44b90b365e770ecdb8f77e13952"
+  },
+  "researcher": {
+    "version": 1,
+    "hash": "853658fda43ddbe0a4d08f2c6e50b5116d29a2e9ccd7f46e173e65920d8f6ace"
+  },
+  "structural-editor": {
+    "version": 2,
+    "hash": "83093baa7262aef8193871a1afcf2b43b11a56fe2d00cade41355cf66d972b74"
+  }
+}

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

@@ -464,6 +464,18 @@
   "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",
@@ -1333,6 +1345,7 @@
   "A short, memorable link you can point at any shared page.": "A short, memorable link you can point at any shared page.",
   "Use 2-60 lowercase letters, digits and hyphens": "Use 2-60 lowercase letters, digits and hyphens",
   "This address is already in use": "This address is already in use",
+  "This address is in use. Saving will move it to this page.": "This address is in use. Saving will move it to this page.",
   "Move custom address?": "Move custom address?",
   "Move here": "Move here",
   "The address \"{{alias}}\" currently points to \"{{title}}\". Move it to this page?": "The address \"{{alias}}\" currently points to \"{{title}}\". Move it to this page?",
@@ -1363,5 +1376,6 @@
   "Already up to date": "Already up to date",
   "Updated to the latest version": "Updated to the latest version",
   "This role is no longer in the catalog": "This role is no longer in the catalog",
-  "This language is no longer available in the catalog": "This language is no longer available in the catalog"
+  "This language is no longer available in the catalog": "This language is no longer available in the catalog",
+  "Connecting… (read-only)": "Connecting… (read-only)"
 }

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

@@ -474,6 +474,18 @@
   "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",
@@ -1190,6 +1202,7 @@
   "A short, memorable link you can point at any shared page.": "Короткая запоминающаяся ссылка, которую можно направить на любую опубликованную страницу.",
   "Use 2-60 lowercase letters, digits and hyphens": "Используйте 2–60 строчных букв, цифр и дефисов",
   "This address is already in use": "Этот адрес уже занят",
+  "This address is in use. Saving will move it to this page.": "Этот адрес уже используется. При сохранении он будет перемещён на эту страницу.",
   "Move custom address?": "Переместить пользовательский адрес?",
   "Move here": "Переместить сюда",
   "The address \"{{alias}}\" currently points to \"{{title}}\". Move it to this page?": "Адрес «{{alias}}» сейчас указывает на «{{title}}». Переместить его на эту страницу?",
@@ -1221,5 +1234,6 @@
   "Already up to date": "Уже актуальна",
   "Updated to the latest version": "Обновлено до последней версии",
   "This role is no longer in the catalog": "Эта роль больше не представлена в каталоге",
-  "This language is no longer available in the catalog": "Этот язык больше не доступен в каталоге"
+  "This language is no longer available in the catalog": "Этот язык больше не доступен в каталоге",
+  "Connecting… (read-only)": "Подключение… (только чтение)"
 }

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/components/layouts/global/app-header.tsx

@@ -10,12 +10,12 @@ import classes from "./app-header.module.css";
 import { BrandLogo } from "@/components/ui/brand-logo";
 import TopMenu from "@/components/layouts/global/top-menu.tsx";
 import { Link } from "react-router-dom";
-import { useAtom, useSetAtom } from "jotai";
+import { useAtom } from "jotai";
 import {
   desktopSidebarAtom,
   mobileSidebarAtom,
 } from "@/components/layouts/global/hooks/atoms/sidebar-atom.ts";
-import { aiChatWindowOpenAtom } from "@/features/ai-chat/atoms/ai-chat-atom.ts";
+import { useOpenAiChatForCurrentPage } from "@/features/ai-chat/hooks/use-open-ai-chat.ts";
 import { workspaceAtom } from "@/features/user/atoms/current-user-atom.ts";
 import { useToggleSidebar } from "@/components/layouts/global/hooks/hooks/use-toggle-sidebar.ts";
 import SidebarToggle from "@/components/ui/sidebar-toggle-button.tsx";
@@ -38,7 +38,9 @@ export function AppHeader() {
   const toggleDesktop = useToggleSidebar(desktopSidebarAtom);
 
   const [workspace] = useAtom(workspaceAtom);
-  const setAiChatWindowOpen = useSetAtom(aiChatWindowOpenAtom);
+  // Opening from the header auto-opens the document's bound chat (last chat
+  // created on the current page); off a page it keeps the current selection.
+  const openAiChat = useOpenAiChatForCurrentPage();
   // AI chat entry point: only shown when the workspace enables it (A7 gate).
   const aiChatEnabled = workspace?.settings?.ai?.chat === true;
 
@@ -105,7 +107,7 @@ export function AppHeader() {
                 color="dark"
                 size="sm"
                 aria-label={t("AI chat")}
-                onClick={() => setAiChatWindowOpen((v) => !v)}
+                onClick={openAiChat}
               >
                 <IconMessage size={20} />
               </ActionIcon>

apps/client/src/features/ai-chat/hooks/use-open-ai-chat.test.tsx

@@ -0,0 +1,135 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { renderHook, act } from "@testing-library/react";
+import { Provider, createStore } from "jotai";
+import type { ReactNode } from "react";
+import { useOpenAiChatForCurrentPage } from "./use-open-ai-chat";
+import {
+  activeAiChatIdAtom,
+  aiChatWindowOpenAtom,
+  aiChatDraftAtom,
+  selectedAiRoleIdAtom,
+} from "@/features/ai-chat/atoms/ai-chat-atom.ts";
+
+// useMatch is the only react-router-dom export the hook uses; drive its return
+// per test to simulate "on a page" vs "off a page".
+const useMatchMock = vi.fn();
+vi.mock("react-router-dom", () => ({
+  useMatch: () => useMatchMock(),
+}));
+
+// The bound-chat resolver is the network boundary; stub it per test.
+const getBoundChatMock = vi.fn();
+vi.mock("@/features/ai-chat/services/ai-chat-service.ts", () => ({
+  getBoundChat: (pageId: string) => getBoundChatMock(pageId),
+}));
+
+// Put the hook on a page route by default ("doc-p1" -> page id "p1"); individual
+// tests override useMatch to go off-page.
+function onPage(pageSlug = "doc-p1") {
+  useMatchMock.mockReturnValue({ params: { pageSlug } });
+}
+function offPage() {
+  useMatchMock.mockReturnValue(null);
+}
+
+// Render the hook inside an explicit jotai store so atom side effects are
+// assertable; the store is returned for setup + assertions.
+function setup(seed?: (store: ReturnType<typeof createStore>) => void) {
+  const store = createStore();
+  seed?.(store);
+  const wrapper = ({ children }: { children: ReactNode }) => (
+    <Provider store={store}>{children}</Provider>
+  );
+  const { result } = renderHook(() => useOpenAiChatForCurrentPage(), { wrapper });
+  return { store, open: () => act(() => result.current()) };
+}
+
+describe("useOpenAiChatForCurrentPage", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    onPage();
+  });
+
+  it("on a page: resolves the bound chat, selects it, and opens the window", async () => {
+    getBoundChatMock.mockResolvedValue("bound-chat-1");
+    const { store, open } = setup((s) => s.set(aiChatDraftAtom, "stale draft"));
+
+    await open();
+
+    expect(getBoundChatMock).toHaveBeenCalledWith("p1");
+    expect(store.get(activeAiChatIdAtom)).toBe("bound-chat-1");
+    expect(store.get(aiChatWindowOpenAtom)).toBe(true);
+    expect(store.get(aiChatDraftAtom)).toBe(""); // cleared on a real switch
+  });
+
+  it("on a page with no bound chat: opens a fresh chat (null)", async () => {
+    getBoundChatMock.mockResolvedValue(null);
+    const { store, open } = setup((s) => s.set(activeAiChatIdAtom, "previous"));
+
+    await open();
+
+    expect(store.get(activeAiChatIdAtom)).toBeNull();
+    expect(store.get(aiChatWindowOpenAtom)).toBe(true);
+  });
+
+  it("off a page: keeps the current selection and does NOT resolve", async () => {
+    offPage();
+    const { store, open } = setup((s) => {
+      s.set(activeAiChatIdAtom, "keep-me");
+      s.set(aiChatDraftAtom, "untouched");
+    });
+
+    await open();
+
+    expect(getBoundChatMock).not.toHaveBeenCalled();
+    expect(store.get(activeAiChatIdAtom)).toBe("keep-me");
+    expect(store.get(aiChatDraftAtom)).toBe("untouched"); // no switch -> kept
+    expect(store.get(aiChatWindowOpenAtom)).toBe(true);
+  });
+
+  it("window already open: re-click does NOT re-resolve or switch chats", async () => {
+    getBoundChatMock.mockResolvedValue("would-switch");
+    const { store, open } = setup((s) => {
+      s.set(aiChatWindowOpenAtom, true);
+      s.set(activeAiChatIdAtom, "current");
+    });
+
+    await open();
+
+    expect(getBoundChatMock).not.toHaveBeenCalled();
+    expect(store.get(activeAiChatIdAtom)).toBe("current");
+    expect(store.get(aiChatWindowOpenAtom)).toBe(true);
+  });
+
+  it("does NOT clear the draft when the resolved chat equals the current one", async () => {
+    getBoundChatMock.mockResolvedValue("same");
+    const { store, open } = setup((s) => {
+      s.set(activeAiChatIdAtom, "same");
+      s.set(aiChatDraftAtom, "in-progress");
+    });
+
+    await open();
+
+    expect(store.get(aiChatDraftAtom)).toBe("in-progress"); // no switch
+    expect(store.get(aiChatWindowOpenAtom)).toBe(true);
+  });
+
+  it("fail-soft: a resolve error opens a fresh chat (null)", async () => {
+    getBoundChatMock.mockRejectedValue(new Error("network"));
+    const { store, open } = setup((s) => s.set(activeAiChatIdAtom, "previous"));
+
+    await open();
+
+    expect(store.get(activeAiChatIdAtom)).toBeNull();
+    expect(store.get(aiChatWindowOpenAtom)).toBe(true);
+  });
+
+  it("clears the picked role on a real switch", async () => {
+    getBoundChatMock.mockResolvedValue("bound");
+    const { store, open } = setup((s) => s.set(selectedAiRoleIdAtom, "role-1"));
+
+    await open();
+
+    expect(store.get(selectedAiRoleIdAtom)).toBeNull();
+  });
+});

apps/client/src/features/ai-chat/hooks/use-open-ai-chat.ts

@@ -0,0 +1,67 @@
+import { useCallback } from "react";
+import { useAtom, useSetAtom } from "jotai";
+import { useMatch } from "react-router-dom";
+import {
+  aiChatWindowOpenAtom,
+  activeAiChatIdAtom,
+  aiChatDraftAtom,
+  selectedAiRoleIdAtom,
+} from "@/features/ai-chat/atoms/ai-chat-atom.ts";
+import { getBoundChat } from "@/features/ai-chat/services/ai-chat-service.ts";
+import { extractPageSlugId } from "@/lib";
+
+/**
+ * The generic "open the AI chat" action, WITH document binding: when invoked
+ * while viewing a page, it resolves that page's bound chat and selects it before
+ * opening — so the last chat for this document re-opens by itself. With no bound
+ * chat (or off a page) it keeps the current selection / opens a fresh chat. Used
+ * by the app-header entry point; NOT by the provenance badge (which deep-links).
+ */
+export function useOpenAiChatForCurrentPage() {
+  const [windowOpen, setWindowOpen] = useAtom(aiChatWindowOpenAtom);
+  const [activeChatId, setActiveChatId] = useAtom(activeAiChatIdAtom);
+  const setDraft = useSetAtom(aiChatDraftAtom);
+  const setSelectedRoleId = useSetAtom(selectedAiRoleIdAtom);
+
+  // Same route-match trick the window uses: read :pageSlug from the pathname.
+  // AiChatWindow lives in a pathless parent layout route, so useParams() can't
+  // see :pageSlug — match the full path against the authenticated page route.
+  const match = useMatch("/s/:spaceSlug/p/:pageSlug");
+  const pageId = extractPageSlugId(match?.params?.pageSlug);
+
+  return useCallback(async () => {
+    // Re-clicks while the window is already open (incl. minimized) must NOT
+    // re-resolve and yank the user to another chat: resolve only on a genuine
+    // closed -> open transition. (`windowOpen` is already true here, so there
+    // is nothing to set — just bail.)
+    if (windowOpen) return;
+    // Open the window FIRST so the control feels instant: the bound-chat
+    // round-trip below must never gate the window appearing, or on a slow
+    // connection the first click reads as a hung control until the POST returns.
+    setWindowOpen(true);
+    let resolved: string | null = activeChatId; // off-a-page: keep current
+    if (pageId) {
+      try {
+        resolved = await getBoundChat(pageId); // null => fresh chat
+      } catch {
+        resolved = null; // fail-soft: a fresh chat is always a safe fallback
+      }
+    }
+    // Clear the composer draft / picked role ONLY on an actual switch, so
+    // reopening the same chat does not wipe an in-progress draft. Applied after
+    // the resolve so the window is already visible while the switch settles.
+    if (resolved !== activeChatId) {
+      setActiveChatId(resolved);
+      setDraft("");
+      setSelectedRoleId(null);
+    }
+  }, [
+    windowOpen,
+    activeChatId,
+    pageId,
+    setWindowOpen,
+    setActiveChatId,
+    setDraft,
+    setSelectedRoleId,
+  ]);
+}

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

@@ -42,6 +42,17 @@ export async function getAiChatMessages(
   return req.data;
 }
 
+/**
+ * Resolve the chat bound to a document (the current user's most-recent chat
+ * created on that page), or null when there is none. Drives auto-open-on-page.
+ */
+export async function getBoundChat(pageId: string): Promise<string | null> {
+  const req = await api.post<{ chatId: string | null }>("/ai-chat/bound-chat", {
+    pageId,
+  });
+  return req.data.chatId;
+}
+
 /** Rename a chat. */
 export async function renameAiChat(data: {
   chatId: string;

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/emoji-menu/utils.test.ts

@@ -0,0 +1,100 @@
+import { describe, it, expect, beforeEach } from "vitest";
+import {
+  sortFrequentlyUsedEmoji,
+  getFrequentlyUsedEmoji,
+  LOCAL_STORAGE_FREQUENT_KEY,
+} from "./utils";
+
+describe("sortFrequentlyUsedEmoji", () => {
+  it("orders known emoji by descending usage count", async () => {
+    const result = await sortFrequentlyUsedEmoji({
+      rocket: 1,
+      joy: 9,
+      heart_eyes: 5,
+    });
+    expect(result.map((e) => e.id)).toEqual(["joy", "heart_eyes", "rocket"]);
+  });
+
+  it("caps the result at the top 5 most frequent", async () => {
+    const result = await sortFrequentlyUsedEmoji({
+      rocket: 1,
+      joy: 2,
+      heart_eyes: 3,
+      grinning: 4,
+      laughing: 5,
+      scream: 6,
+      sweat_smile: 7,
+    });
+    expect(result).toHaveLength(5);
+    // Highest counts retained, lowest (rocket:1, joy:2) dropped.
+    expect(result.map((e) => e.id)).toEqual([
+      "sweat_smile",
+      "scream",
+      "laughing",
+      "grinning",
+      "heart_eyes",
+    ]);
+  });
+
+  it("drops ids that have no matching emoji in the index", async () => {
+    const result = await sortFrequentlyUsedEmoji({
+      __definitely_not_a_real_emoji_id__: 100,
+      rocket: 1,
+    });
+    expect(result.map((e) => e.id)).toEqual(["rocket"]);
+  });
+
+  it("maps each entry to its native glyph and a command", async () => {
+    const [entry] = await sortFrequentlyUsedEmoji({ rocket: 5 });
+    expect(entry.id).toBe("rocket");
+    expect(typeof entry.emoji).toBe("string");
+    expect(entry.emoji.length).toBeGreaterThan(0);
+    expect(typeof entry.command).toBe("function");
+  });
+
+  it("returns an empty list for empty input", async () => {
+    expect(await sortFrequentlyUsedEmoji({})).toEqual([]);
+  });
+});
+
+describe("getFrequentlyUsedEmoji", () => {
+  beforeEach(() => {
+    localStorage.clear();
+  });
+
+  it("falls back to the default map when nothing is stored", () => {
+    const result = getFrequentlyUsedEmoji();
+    expect(result["+1"]).toBe(10);
+    expect(result["rocket"]).toBe(1);
+  });
+
+  it("parses a valid stored JSON map", () => {
+    localStorage.setItem(
+      LOCAL_STORAGE_FREQUENT_KEY,
+      JSON.stringify({ rocket: 42 }),
+    );
+    expect(getFrequentlyUsedEmoji()).toEqual({ rocket: 42 });
+  });
+
+  // BUG (issue #204, Phase 2): getFrequentlyUsedEmoji() does an unprotected
+  // JSON.parse() of the raw localStorage value. A corrupt value (e.g. truncated
+  // by a crash, or written by another tab/extension) makes the emoji menu throw
+  // on open instead of degrading gracefully to the default set.
+  //
+  // Documented with it.fails: this asserts the DESIRED behavior (return a sane
+  // default, never throw). It currently FAILS because the function throws —
+  // flip to `it()` once utils.ts guards the JSON.parse.
+  it.fails(
+    "should degrade to a sane default on corrupt localStorage (currently throws)",
+    () => {
+      localStorage.setItem(LOCAL_STORAGE_FREQUENT_KEY, "{not valid json");
+      let result: Record<string, number> | undefined;
+      expect(() => {
+        result = getFrequentlyUsedEmoji();
+      }).not.toThrow();
+      // Should hand back a usable, non-empty map rather than nothing.
+      expect(result).toBeTruthy();
+      expect(Object.keys(result ?? {}).length).toBeGreaterThan(0);
+    },
+  );
+});

apps/client/src/features/editor/components/table/handle/lib/sort-cells.test.ts

@@ -0,0 +1,163 @@
+import { describe, it, expect } from "vitest";
+import type { Node as ProseMirrorNode } from "@tiptap/pm/model";
+import {
+  isHeaderCell,
+  sortItems,
+  weaveItems,
+  type SortableItem,
+} from "./sort-cells";
+
+// isHeaderCell only reads node.type.name and node.attrs?.header, so a minimal
+// duck-typed node is sufficient (no real ProseMirror schema needed).
+function fakeNode(typeName: string, attrs: Record<string, unknown> = {}) {
+  return { type: { name: typeName }, attrs } as unknown as ProseMirrorNode;
+}
+
+function item<T>(
+  payload: T,
+  text: string,
+  originalOrder: number,
+  opts: { isHeader?: boolean; isEmpty?: boolean } = {},
+): SortableItem<T> {
+  return {
+    payload,
+    text,
+    originalOrder,
+    isHeader: opts.isHeader ?? false,
+    isEmpty: opts.isEmpty ?? text.trim() === "",
+  };
+}
+
+describe("isHeaderCell", () => {
+  it("recognizes the tableHeader node type", () => {
+    expect(isHeaderCell(fakeNode("tableHeader"))).toBe(true);
+  });
+
+  it("recognizes the snake_case table_header node type", () => {
+    expect(isHeaderCell(fakeNode("table_header"))).toBe(true);
+  });
+
+  it("treats a plain cell with header:true attr as a header", () => {
+    expect(isHeaderCell(fakeNode("tableCell", { header: true }))).toBe(true);
+  });
+
+  it("returns false for a regular body cell", () => {
+    expect(isHeaderCell(fakeNode("tableCell", { header: false }))).toBe(false);
+    expect(isHeaderCell(fakeNode("tableCell"))).toBe(false);
+  });
+});
+
+describe("sortItems", () => {
+  it("sorts non-empty rows ascending using a base/numeric collator", () => {
+    const data = [
+      item("c", "cherry", 0),
+      item("a", "Apple", 1),
+      item("b", "banana", 2),
+    ];
+    expect(sortItems(data, "asc").map((i) => i.payload)).toEqual([
+      "a",
+      "b",
+      "c",
+    ]);
+  });
+
+  it("sorts descending when direction is desc", () => {
+    const data = [
+      item("a", "apple", 0),
+      item("b", "banana", 1),
+      item("c", "cherry", 2),
+    ];
+    expect(sortItems(data, "desc").map((i) => i.payload)).toEqual([
+      "c",
+      "b",
+      "a",
+    ]);
+  });
+
+  it("orders numerically, not lexically (numeric collator)", () => {
+    const data = [
+      item("ten", "10", 0),
+      item("two", "2", 1),
+      item("one", "1", 2),
+    ];
+    expect(sortItems(data, "asc").map((i) => i.payload)).toEqual([
+      "one",
+      "two",
+      "ten",
+    ]);
+  });
+
+  it("always pushes empty cells to the bottom regardless of direction", () => {
+    const data = [
+      item("empty", "", 0, { isEmpty: true }),
+      item("b", "banana", 1),
+      item("a", "apple", 2),
+    ];
+    const asc = sortItems(data, "asc");
+    expect(asc.map((i) => i.payload)).toEqual(["a", "b", "empty"]);
+    const desc = sortItems(data, "desc");
+    // Empty stays last even when the rest is reversed.
+    expect(desc[desc.length - 1].payload).toBe("empty");
+  });
+
+  it("keeps empty cells in their original relative order (stable)", () => {
+    const data = [
+      item("e1", "", 5, { isEmpty: true }),
+      item("e2", "", 2, { isEmpty: true }),
+      item("a", "apple", 9),
+    ];
+    const sorted = sortItems(data, "asc");
+    // e2 (originalOrder 2) before e1 (originalOrder 5).
+    expect(sorted.map((i) => i.payload)).toEqual(["a", "e2", "e1"]);
+  });
+
+  it("does not mutate the input array", () => {
+    const data = [item("b", "banana", 0), item("a", "apple", 1)];
+    const snapshot = data.map((i) => i.payload);
+    sortItems(data, "asc");
+    expect(data.map((i) => i.payload)).toEqual(snapshot);
+  });
+});
+
+describe("weaveItems", () => {
+  it("keeps header rows pinned in place and fills body slots from sorted data", () => {
+    const header = item("H", "Name", 0, { isHeader: true });
+    const all = [
+      header,
+      item("orig-b", "b", 1),
+      item("orig-a", "a", 2),
+    ];
+    const sortedBody = [item("orig-a", "a", 2), item("orig-b", "b", 1)];
+
+    const woven = weaveItems(all, sortedBody);
+    // Header never moves out of row 0...
+    expect(woven[0]).toBe(header);
+    // ...and the body positions are filled in sorted order.
+    expect(woven.slice(1).map((i) => i.payload)).toEqual(["orig-a", "orig-b"]);
+  });
+
+  it("does not consume body data for header positions (header stays at top)", () => {
+    const header = item("H", "head", 0, { isHeader: true });
+    const all = [header, item("x", "x", 1), item("y", "y", 2)];
+    const sortedBody = [item("y", "y", 2), item("x", "x", 1)];
+    const woven = weaveItems(all, sortedBody);
+    expect(woven[0].isHeader).toBe(true);
+    expect(woven.filter((i) => !i.isHeader).map((i) => i.payload)).toEqual([
+      "y",
+      "x",
+    ]);
+  });
+
+  it("interleaves correctly when a header sits between body rows", () => {
+    const header = item("H", "head", 1, { isHeader: true });
+    const all = [
+      item("b1", "b1", 0),
+      header,
+      item("b2", "b2", 2),
+    ];
+    const sortedBody = [item("b2", "b2", 2), item("b1", "b1", 0)];
+    const woven = weaveItems(all, sortedBody);
+    expect(woven.map((i) => i.payload)).toEqual(["b2", "H", "b1"]);
+    expect(woven[1]).toBe(header);
+  });
+});

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/editor-sync-state.test.ts

@@ -0,0 +1,32 @@
+import { describe, it, expect } from "vitest";
+import { WebSocketStatus } from "@hocuspocus/provider";
+import { isCollabSynced, isBodyEditable } from "./editor-sync-state";
+
+describe("isCollabSynced", () => {
+  it("is true only when Connected and synced", () => {
+    expect(isCollabSynced(WebSocketStatus.Connected, true)).toBe(true);
+  });
+
+  it("is false while connecting or not yet synced", () => {
+    expect(isCollabSynced(WebSocketStatus.Connecting, true)).toBe(false);
+    expect(isCollabSynced(WebSocketStatus.Connected, false)).toBe(false);
+    expect(isCollabSynced(WebSocketStatus.Disconnected, true)).toBe(false);
+  });
+});
+
+describe("isBodyEditable (pre-sync data-loss gate, #218)", () => {
+  const base = { editable: true, inEditMode: true, showStatic: false };
+
+  it("allows editing only after the static (pre-sync) phase ends", () => {
+    expect(isBodyEditable(base)).toBe(true);
+  });
+
+  it("never editable while the static read-only editor is shown", () => {
+    expect(isBodyEditable({ ...base, showStatic: true })).toBe(false);
+  });
+
+  it("honors read-only and view mode", () => {
+    expect(isBodyEditable({ ...base, editable: false })).toBe(false);
+    expect(isBodyEditable({ ...base, inEditMode: false })).toBe(false);
+  });
+});

apps/client/src/features/editor/editor-sync-state.ts

@@ -0,0 +1,32 @@
+import { WebSocketStatus } from "@hocuspocus/provider";
+
+/**
+ * The collab document is usable only once the provider is Connected AND has
+ * synced (both the local IndexedDB replica and the remote room). Until then the
+ * in-browser Y.Doc is empty/stale, so edits would either be dropped or clobber
+ * the server's authoritative doc when it finally arrives.
+ */
+export function isCollabSynced(
+  status: WebSocketStatus | string,
+  isSynced: boolean,
+): boolean {
+  return status === WebSocketStatus.Connected && isSynced;
+}
+
+/**
+ * Whether the page BODY editor may accept edits.
+ *
+ * `showStatic` is true during the pre-sync window (a read-only static editor is
+ * shown). Gating editability on `!showStatic` guarantees the body never becomes
+ * editable before the collab doc is synced, so early keystrokes on a freshly
+ * created page can't land only in local ProseMirror and then be lost when the
+ * server's initial empty doc syncs in (#218). Read-only and view modes are
+ * still honored via `editable`/`inEditMode`.
+ */
+export function isBodyEditable(opts: {
+  editable: boolean;
+  inEditMode: boolean;
+  showStatic: boolean;
+}): boolean {
+  return opts.editable && opts.inEditMode && !opts.showStatic;
+}

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

@@ -0,0 +1,168 @@
+import { describe, it, expect } from "vitest";
+import { Editor } from "@tiptap/core";
+import { Document } from "@tiptap/extension-document";
+import { Paragraph } from "@tiptap/extension-paragraph";
+import { Text } from "@tiptap/extension-text";
+import { Node as PMNode, Fragment, Slice } from "@tiptap/pm/model";
+import {
+  FootnoteReference,
+  FootnotesList,
+  FootnoteDefinition,
+  FOOTNOTE_REFERENCE_NAME,
+  FOOTNOTE_DEFINITION_NAME,
+  FOOTNOTES_LIST_NAME,
+} from "@docmost/editor-ext";
+import { canonicalizePastedFootnotes } from "./markdown-clipboard";
+
+/**
+ * A markdown paste builds its ProseMirror fragment via DOM -> parseSlice and is
+ * applied with a manual transaction (handlePaste returns true), so it bypasses
+ * the editor's footnoteSyncPlugin — which never reorders an existing list. These
+ * tests pin canonicalizePastedFootnotes, the focused hook that makes a pasted
+ * out-of-order markdown footnote block come out canonical (issue #228).
+ */
+
+const extensions = [
+  Document,
+  Paragraph,
+  Text,
+  FootnoteReference,
+  FootnotesList,
+  FootnoteDefinition,
+];
+
+function makeSchema() {
+  const editor = new Editor({ extensions, content: { type: "doc", content: [] } });
+  const { schema } = editor;
+  return { editor, schema };
+}
+
+/** List footnote def ids of the (single) footnotesList in a slice, in order. */
+function listIds(slice: Slice): string[] {
+  const out: string[] = [];
+  slice.content.forEach((node: PMNode) => {
+    if (node.type.name === FOOTNOTES_LIST_NAME) {
+      node.content.forEach((def: PMNode) => {
+        if (def.type.name === FOOTNOTE_DEFINITION_NAME) out.push(def.attrs.id);
+      });
+    }
+  });
+  return out;
+}
+
+function hasList(slice: Slice): boolean {
+  let found = false;
+  slice.content.forEach((n: PMNode) => {
+    if (n.type.name === FOOTNOTES_LIST_NAME) found = true;
+  });
+  return found;
+}
+
+describe("canonicalizePastedFootnotes", () => {
+  it("reorders a pasted block to reference order, dedups reuse, drops orphans", () => {
+    const { editor, schema } = makeSchema();
+    // Body references c, a, b (and again a => reuse); definitions a, b, c, z
+    // (z is an orphan) — the exact shape a markdown paste produces.
+    const slice = new Slice(
+      Fragment.fromArray([
+        schema.nodes.paragraph.create(null, [
+          schema.text("body "),
+          schema.nodes[FOOTNOTE_REFERENCE_NAME].create({ id: "c" }),
+          schema.nodes[FOOTNOTE_REFERENCE_NAME].create({ id: "a" }),
+          schema.nodes[FOOTNOTE_REFERENCE_NAME].create({ id: "b" }),
+          schema.nodes[FOOTNOTE_REFERENCE_NAME].create({ id: "a" }),
+        ]),
+        schema.nodes[FOOTNOTES_LIST_NAME].create(null, [
+          schema.nodes[FOOTNOTE_DEFINITION_NAME].create({ id: "a" }, [
+            schema.nodes.paragraph.create(null, [schema.text("note A")]),
+          ]),
+          schema.nodes[FOOTNOTE_DEFINITION_NAME].create({ id: "b" }, [
+            schema.nodes.paragraph.create(null, [schema.text("note B")]),
+          ]),
+          schema.nodes[FOOTNOTE_DEFINITION_NAME].create({ id: "c" }, [
+            schema.nodes.paragraph.create(null, [schema.text("note C")]),
+          ]),
+          schema.nodes[FOOTNOTE_DEFINITION_NAME].create({ id: "z" }, [
+            schema.nodes.paragraph.create(null, [schema.text("orphan")]),
+          ]),
+        ]),
+      ]),
+      0,
+      0,
+    );
+
+    const out = canonicalizePastedFootnotes(slice, schema);
+    // Reference order, orphan z dropped, reused a appears once.
+    expect(listIds(out)).toEqual(["c", "a", "b"]);
+    editor.destroy();
+  });
+
+  it("leaves a reference-ONLY paste untouched (no synthesized definitions)", () => {
+    // A paste that reuses an id defined in the TARGET doc must NOT gain a
+    // synthesized empty definition here — it carries no footnotesList of its own.
+    const { editor, schema } = makeSchema();
+    const slice = new Slice(
+      Fragment.from(
+        schema.nodes.paragraph.create(null, [
+          schema.text("see "),
+          schema.nodes[FOOTNOTE_REFERENCE_NAME].create({ id: "a" }),
+        ]),
+      ),
+      0,
+      0,
+    );
+    const out = canonicalizePastedFootnotes(slice, schema);
+    expect(hasList(out)).toBe(false);
+    expect(out).toBe(slice); // returned unchanged (same reference)
+    editor.destroy();
+  });
+
+  it("leaves a definitions-ONLY paste untouched (no references -> no empty paste)", () => {
+    // A whole-block paste of ONLY definitions (a footnotesList with no matching
+    // footnoteReference anywhere in the selection). Canonicalizing it would strip
+    // the reference-less list -> an EMPTY paste, losing the pasted text. The hook
+    // must leave such a block untouched.
+    const { editor, schema } = makeSchema();
+    const slice = new Slice(
+      Fragment.fromArray([
+        schema.nodes[FOOTNOTES_LIST_NAME].create(null, [
+          schema.nodes[FOOTNOTE_DEFINITION_NAME].create({ id: "a" }, [
+            schema.nodes.paragraph.create(null, [schema.text("note A")]),
+          ]),
+          schema.nodes[FOOTNOTE_DEFINITION_NAME].create({ id: "b" }, [
+            schema.nodes.paragraph.create(null, [schema.text("note B")]),
+          ]),
+        ]),
+      ]),
+      0,
+      0,
+    );
+    const out = canonicalizePastedFootnotes(slice, schema);
+    expect(out).toBe(slice); // returned unchanged (same reference, content kept)
+    expect(listIds(out)).toEqual(["a", "b"]);
+    editor.destroy();
+  });
+
+  it("leaves an open (partial) slice untouched even if it carries a list", () => {
+    // An open slice (openStart/openEnd > 0) is a partial selection, not a
+    // standalone block, so it is returned as-is BEFORE any footnote handling.
+    const { editor, schema } = makeSchema();
+    const slice = new Slice(
+      Fragment.fromArray([
+        schema.nodes.paragraph.create(null, [
+          schema.nodes[FOOTNOTE_REFERENCE_NAME].create({ id: "a" }),
+        ]),
+        schema.nodes[FOOTNOTES_LIST_NAME].create(null, [
+          schema.nodes[FOOTNOTE_DEFINITION_NAME].create({ id: "a" }, [
+            schema.nodes.paragraph.create(null, [schema.text("A")]),
+          ]),
+        ]),
+      ]),
+      1,
+      1,
+    );
+    const out = canonicalizePastedFootnotes(slice, schema);
+    expect(out).toBe(slice);
+    editor.destroy();
+  });
+});

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

@@ -0,0 +1,126 @@
+import { describe, it, expect } from "vitest";
+import { normalizeTableColumnWidths } from "./markdown-clipboard";
+
+// normalizeTableColumnWidths mutates a DOM subtree (jsdom provides document).
+function root(html: string): HTMLElement {
+  const div = document.createElement("div");
+  div.innerHTML = html;
+  return div;
+}
+
+function firstRowColWidths(container: HTMLElement): (string | null)[] {
+  const row = container.querySelector("tr");
+  return Array.from(row?.children ?? []).map((c) =>
+    c.getAttribute("colwidth"),
+  );
+}
+
+describe("normalizeTableColumnWidths", () => {
+  // The core "squash столбцов вставленной таблицы" concern: markdown has no
+  // widths, so every pasted table would otherwise render at table-layout:fixed
+  // / 100% and squash columns. This stamps an explicit per-column px width.
+  it("stamps the default px width on every column when no widths are present", () => {
+    const container = root(
+      "<table><tbody><tr><td>a</td><td>b</td><td>c</td></tr></tbody></table>",
+    );
+    normalizeTableColumnWidths(container);
+    expect(firstRowColWidths(container)).toEqual(["150", "150", "150"]);
+  });
+
+  it("derives column widths from a colgroup", () => {
+    const container = root(
+      "<table>" +
+        '<colgroup><col style="width:200px"><col style="width:80px"></colgroup>' +
+        "<tbody><tr><td>a</td><td>b</td></tr></tbody>" +
+        "</table>",
+    );
+    normalizeTableColumnWidths(container);
+    expect(firstRowColWidths(container)).toEqual(["200", "80"]);
+  });
+
+  it("derives column widths from per-cell width attributes", () => {
+    const container = root(
+      '<table><tbody><tr><td width="120">a</td><td width="90">b</td></tr></tbody></table>',
+    );
+    normalizeTableColumnWidths(container);
+    expect(firstRowColWidths(container)).toEqual(["120", "90"]);
+  });
+
+  it("derives column widths from a cell style:width:px", () => {
+    const container = root(
+      '<table><tbody><tr><td style="width:140px">a</td><td>b</td></tr></tbody></table>',
+    );
+    normalizeTableColumnWidths(container);
+    // First cell width parsed; a fully-unmeasured column is left untouched
+    // (the 100 fallback only fills in NULL gaps inside an otherwise-measured
+    // multi-column slice, e.g. a colspan).
+    expect(firstRowColWidths(container)).toEqual(["140", null]);
+  });
+
+  it("fills a null gap inside a measured colspanned slice with 100", () => {
+    // colgroup gives [200, null]; the single colspan=2 cell spans both, so its
+    // slice is [200, null] -> the null is backfilled to 100 => "200,100".
+    const container = root(
+      "<table>" +
+        '<colgroup><col style="width:200px"><col></colgroup>' +
+        '<tbody><tr><td colspan="2">merged</td></tr></tbody>' +
+        "</table>",
+    );
+    normalizeTableColumnWidths(container);
+    expect(firstRowColWidths(container)).toEqual(["200,100"]);
+  });
+
+  it("splits a measured width across a colspanned cell", () => {
+    const container = root(
+      '<table><tbody><tr><td colspan="2" width="300">merged</td><td width="100">x</td></tr></tbody></table>',
+    );
+    normalizeTableColumnWidths(container);
+    // 300 / colspan(2) = 150 per underlying column => "150,150" on the merged cell.
+    expect(firstRowColWidths(container)).toEqual(["150,150", "100"]);
+  });
+
+  it("falls back to the default width per spanned column when nothing is measurable", () => {
+    const container = root(
+      '<table><tbody><tr><td colspan="2">merged</td><td>x</td></tr></tbody></table>',
+    );
+    normalizeTableColumnWidths(container);
+    expect(firstRowColWidths(container)).toEqual(["150,150", "150"]);
+  });
+
+  it("leaves cells that already have a colwidth untouched", () => {
+    const container = root(
+      '<table><tbody><tr><td colwidth="42">a</td><td>b</td></tr></tbody></table>',
+    );
+    normalizeTableColumnWidths(container);
+    expect(firstRowColWidths(container)).toEqual(["42", "150"]);
+  });
+
+  it("normalizes every table in the subtree", () => {
+    const container = root(
+      "<table><tbody><tr><td>a</td></tr></tbody></table>" +
+        "<table><tbody><tr><td>b</td><td>c</td></tr></tbody></table>",
+    );
+    normalizeTableColumnWidths(container);
+    const tables = container.querySelectorAll("table");
+    const widths = Array.from(tables).map((t) =>
+      Array.from(t.querySelector("tr")!.children).map((c) =>
+        c.getAttribute("colwidth"),
+      ),
+    );
+    expect(widths).toEqual([["150"], ["150", "150"]]);
+  });
+
+  it("only annotates the first row (column widths are defined once)", () => {
+    const container = root(
+      "<table><tbody>" +
+        "<tr><td>a</td><td>b</td></tr>" +
+        "<tr><td>c</td><td>d</td></tr>" +
+        "</tbody></table>",
+    );
+    normalizeTableColumnWidths(container);
+    const rows = container.querySelectorAll("tr");
+    expect(
+      Array.from(rows[1].children).map((c) => c.getAttribute("colwidth")),
+    ).toEqual([null, null]);
+  });
+});

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

@@ -3,7 +3,14 @@ import { Extension } from "@tiptap/core";
 import { Plugin, PluginKey, TextSelection } from "@tiptap/pm/state";
 import { DOMParser, DOMSerializer, Fragment, Slice } from "@tiptap/pm/model";
 import { find } from "linkifyjs";
-import { markdownToHtml, htmlToMarkdown } from "@docmost/editor-ext";
+import {
+  markdownToHtml,
+  htmlToMarkdown,
+  canonicalizeFootnotes,
+  FOOTNOTES_LIST_NAME,
+  FOOTNOTE_REFERENCE_NAME,
+} from "@docmost/editor-ext";
+import type { Schema } from "@tiptap/pm/model";
 
 export const MarkdownClipboard = Extension.create({
   name: "markdownClipboard",
@@ -83,12 +90,25 @@ export const MarkdownClipboard = Extension.create({
             const body = elementFromString(parsed);
             normalizeTableColumnWidths(body);
 
-            const contentNodes = DOMParser.fromSchema(
+            const parsedSlice = DOMParser.fromSchema(
               this.editor.schema,
             ).parseSlice(body, {
               preserveWhitespace: true,
             });
 
+            // A markdown paste builds its ProseMirror fragment directly (DOM ->
+            // parseSlice), bypassing the editor's footnoteSyncPlugin, which never
+            // reorders an existing list. So a pasted markdown block whose footnote
+            // definitions are out of order (or contains orphan defs) would be
+            // stored out of order. Canonicalize the self-contained pasted block so
+            // its footnotes come out reference-ordered, deduped and orphan-free
+            // (issue #228). See canonicalizePastedFootnotes for why this is scoped
+            // to whole-block pastes that carry their own footnotesList.
+            const contentNodes = canonicalizePastedFootnotes(
+              parsedSlice,
+              this.editor.schema,
+            );
+
             tr.replaceRange(from, to, contentNodes);
             const insertEnd = tr.mapping.map(from, 1);
             tr.setSelection(TextSelection.near(tr.doc.resolve(Math.max(from, insertEnd - 2)), -1));
@@ -133,6 +153,54 @@ export const MarkdownClipboard = Extension.create({
   },
 });
 
+/**
+ * Reorder/dedup the footnotes of a SELF-CONTAINED pasted markdown block to the
+ * canonical invariant (the live footnoteSyncPlugin never reorders an existing
+ * list, so an out-of-order pasted block would otherwise persist out of order).
+ *
+ * Scoped deliberately to whole-block pastes (openStart/openEnd === 0) that carry
+ * their OWN footnotesList: canonicalizeFootnotes would synthesize empty
+ * definitions for any reference lacking a definition, which is correct for a
+ * standalone block but would be wrong for a reference-only paste that REUSES a
+ * footnote already defined in the target document — so those are left untouched
+ * for the paste/sync plugins to merge. Residual: when the pasted block is merged
+ * into a doc that already has footnotes, ordering RELATIVE to the pre-existing
+ * footnotes is still governed by the sync plugin (which does not reorder).
+ *
+ * Also requires at least one footnoteReference in the selection: a definitions-ONLY
+ * paste (`[^a]: …` with no `[^a]` reference in the same block) has no references,
+ * so canonicalizeFootnotes would drop the whole list and the paste would come out
+ * EMPTY — losing the pasted text. Such a block is left as-is for the sync plugin.
+ */
+export function canonicalizePastedFootnotes(slice: Slice, schema: Schema): Slice {
+  if (slice.openStart !== 0 || slice.openEnd !== 0) return slice;
+
+  let hasFootnotesList = false;
+  let hasReference = false;
+  slice.content.forEach((node) => {
+    if (node.type.name === FOOTNOTES_LIST_NAME) hasFootnotesList = true;
+    // footnoteReference is an inline atom, never a top-level slice child here
+    // (this function early-returns for open slices, so children are whole
+    // blocks), so it is only reachable by descending.
+    node.descendants((child) => {
+      if (child.type.name === FOOTNOTE_REFERENCE_NAME) hasReference = true;
+    });
+  });
+  if (!hasFootnotesList) return slice;
+  // No reference anywhere -> a definitions-only paste; canonicalizing would strip
+  // the reference-less list (empty paste). Leave it untouched.
+  if (!hasReference) return slice;
+
+  const content = slice.content.toJSON();
+  if (!Array.isArray(content)) return slice;
+
+  const canonical = canonicalizeFootnotes({ type: "doc", content }) as {
+    content?: unknown[];
+  };
+  const fragment = Fragment.fromJSON(schema, canonical.content ?? []);
+  return new Slice(fragment, 0, 0);
+}
+
 function elementFromString(value) {
   // add a wrapper to preserve leading and trailing whitespace
   const wrappedValue = `<body>${value}</body>`;

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";
@@ -84,6 +73,10 @@ import { PageEmbedLookupProvider } from "@/features/editor/components/page-embed
 import { PageEmbedAncestryProvider } from "@/features/editor/components/page-embed/page-embed-ancestry-context";
 import PageEmbedPicker from "@/features/editor/components/page-embed/page-embed-picker";
 import { useTranslation } from "react-i18next";
+import {
+  isBodyEditable,
+  isCollabSynced,
+} from "@/features/editor/editor-sync-state";
 
 interface PageEditorProps {
   pageId: string;
@@ -99,7 +92,6 @@ export default function PageEditor({
   canComment,
 }: PageEditorProps) {
   const { t } = useTranslation();
-  const collaborationURL = useCollaborationUrl();
   const isComponentMounted = useRef(false);
   const editorRef = useRef<Editor | null>(null);
 
@@ -113,22 +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);
@@ -137,141 +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(
     {
@@ -440,6 +306,9 @@ export default function PageEditor({
 
   const isSynced = isLocalSynced && isRemoteSynced;
 
+  const hasConnectedOnceRef = useRef(false);
+  const [showStatic, setShowStatic] = useState(true);
+
   useEffect(() => {
     const timeout = setTimeout(() => {
       if (yjsConnectionStatus === WebSocketStatus.Connecting || !isSynced) {
@@ -451,17 +320,21 @@ export default function PageEditor({
   }, [yjsConnectionStatus, isSynced]);
   useEffect(() => {
     if (!editor) return;
-    editor.setEditable(editable && currentPageEditMode === PageEditMode.Edit);
-  }, [currentPageEditMode, editor, editable]);
-
-  const hasConnectedOnceRef = useRef(false);
-  const [showStatic, setShowStatic] = useState(true);
+    // Keep the body read-only until the collab doc has synced (showStatic), so
+    // early keystrokes on a freshly created page can't be lost (#218).
+    editor.setEditable(
+      isBodyEditable({
+        editable,
+        inEditMode: currentPageEditMode === PageEditMode.Edit,
+        showStatic,
+      }),
+    );
+  }, [currentPageEditMode, editor, editable, showStatic]);
 
   useEffect(() => {
     if (
       !hasConnectedOnceRef.current &&
-      yjsConnectionStatus === WebSocketStatus.Connected &&
-      isSynced
+      isCollabSynced(yjsConnectionStatus, isSynced)
     ) {
       hasConnectedOnceRef.current = true;
       setShowStatic(false);
@@ -473,17 +346,43 @@ export default function PageEditor({
       <PageEmbedLookupProvider>
         <PageEmbedAncestryProvider hostPageId={pageId}>
       {showStatic ? (
-        <EditorProvider
-          editable={false}
-          immediatelyRender={true}
-          extensions={mainExtensions}
-          content={content}
-          editorProps={{
-            attributes: {
-              "aria-label": t("Page content"),
-            },
-          }}
-        />
+        <div style={{ position: "relative" }}>
+          {/* Surface the pre-sync read-only window so edits typed before the
+              collab provider connects aren't silently swallowed (#218). Shown
+              only when the user is otherwise allowed to edit. */}
+          {editable && currentPageEditMode === PageEditMode.Edit && (
+            <div
+              role="status"
+              aria-live="polite"
+              className="print-hide"
+              style={{
+                position: "absolute",
+                top: 0,
+                right: 0,
+                zIndex: 2,
+                padding: "2px 8px",
+                fontSize: "12px",
+                borderRadius: "4px",
+                background: "var(--mantine-color-gray-light)",
+                color: "var(--mantine-color-dimmed)",
+                pointerEvents: "none",
+              }}
+            >
+              {t("Connecting… (read-only)")}
+            </div>
+          )}
+          <EditorProvider
+            editable={false}
+            immediatelyRender={true}
+            extensions={mainExtensions}
+            content={content}
+            editorProps={{
+              attributes: {
+                "aria-label": t("Page content"),
+              },
+            }}
+          />
+        </div>
       ) : (
         <div className="editor-container" style={{ position: "relative" }}>
           <div ref={menuContainerRef}>
@@ -513,7 +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/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/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 +1,373 @@
+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();
+  });
+});
+
+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();
+    await expect(promise).resolves.toBeUndefined();
+
+    // 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 and cleans up after the timeout when synced never fires", async () => {
+    vi.useFakeTimers();
+    const promise = warmPageYdoc("p1", "ws://x");
+
+    // Do not fire "synced"; let the 8s safety timeout settle it.
+    await vi.advanceTimersByTimeAsync(8000);
+    await expect(promise).resolves.toBeUndefined();
+
+    expect(h.providerDestroy).toHaveBeenCalledTimes(1);
+    expect(h.idbDestroy).toHaveBeenCalledTimes(1);
+    expect(h.ydocDestroy).toHaveBeenCalledTimes(1);
+  });
+});

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

@@ -0,0 +1,315 @@
+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.
+ *
+ * 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<void> {
+  let ydoc: Y.Doc | null = null;
+  let local: IndexeddbPersistence | null = null;
+  let remote: HocuspocusProvider | null = null;
+
+  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;
+      const finish = () => {
+        if (settled) return;
+        settled = true;
+        // Clear the pending timeout and detach the listener so neither leaks
+        // after we resolve.
+        if (timeoutId !== undefined) clearTimeout(timeoutId);
+        try {
+          provider.off("synced", finish);
+        } catch {
+          // best-effort
+        }
+        resolve();
+      };
+
+      // Resolve once the server state has synced into the local doc...
+      provider.on("synced", finish);
+      // ...or give up after a short timeout so we never hang.
+      timeoutId = setTimeout(finish, 8000);
+    });
+  } catch {
+    // best-effort
+  } finally {
+    try {
+      remote?.destroy();
+    } catch {
+      // best-effort
+    }
+    try {
+      local?.destroy();
+    } catch {
+      // best-effort
+    }
+    try {
+      ydoc?.destroy();
+    } catch {
+      // best-effort
+    }
+  }
+}

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/breadcrumbs/breadcrumb.tsx

@@ -1,7 +1,7 @@
 import { useAtomValue } from "jotai";
 import { treeDataAtom } from "@/features/page/tree/atoms/tree-data-atom.ts";
 import React, { useCallback, useEffect, useState } from "react";
-import { findBreadcrumbPath } from "@/features/page/tree/utils";
+import { computeBreadcrumbState } from "./breadcrumb.utils";
 import {
   Button,
   Anchor,
@@ -15,8 +15,12 @@ import { IconCornerDownRightDouble, IconDots } from "@tabler/icons-react";
 import { Link, useParams } from "react-router-dom";
 import classes from "./breadcrumb.module.css";
 import { SpaceTreeNode } from "@/features/page/tree/types.ts";
+import { IPage } from "@/features/page/types/page.types.ts";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
-import { usePageQuery } from "@/features/page/queries/page-query.ts";
+import {
+  usePageQuery,
+  usePageBreadcrumbsQuery,
+} from "@/features/page/queries/page-query.ts";
 import { extractPageSlugId } from "@/lib";
 import { useMediaQuery } from "@mantine/hooks";
 import { useTranslation } from "react-i18next";
@@ -38,14 +42,29 @@ export default function Breadcrumb() {
   const { data: currentPage } = usePageQuery({
     pageId: extractPageSlugId(pageSlug),
   });
+  // The page's own ancestor chain, fetched independently of the lazily-built
+  // sidebar tree so a deep page doesn't render a blank breadcrumb for seconds
+  // while the tree backfills (#218).
+  const { data: ancestors } = usePageBreadcrumbsQuery(currentPage?.id);
   const isMobile = useMediaQuery("(max-width: 48em)");
 
   useEffect(() => {
-    if (treeData?.length > 0 && currentPage) {
-      const breadcrumb = findBreadcrumbPath(treeData, currentPage.id);
-      setBreadcrumbNodes(breadcrumb || null);
-    }
-  }, [currentPage?.id, treeData]);
+    if (!currentPage) return;
+
+    // Selection/mapping + stale-clearing live in a pure, unit-tested helper
+    // (#218). It resolves the correct chain when possible and, on a transient
+    // miss, clears a chain left over from a previously-viewed page instead of
+    // showing the wrong trail — while keeping a chain already resolved for THIS
+    // page to avoid a blank flash.
+    setBreadcrumbNodes((previous) =>
+      computeBreadcrumbState(
+        treeData,
+        ancestors as IPage[] | undefined,
+        currentPage.id,
+        previous,
+      ),
+    );
+  }, [currentPage?.id, treeData, ancestors]);
 
   const HiddenNodesTooltipContent = () =>
     breadcrumbNodes?.slice(1, -1).map((node) => (

apps/client/src/features/page/components/breadcrumbs/breadcrumb.utils.test.ts

@@ -0,0 +1,114 @@
+import { describe, it, expect } from "vitest";
+import {
+  computeBreadcrumbState,
+  resolveBreadcrumbNodes,
+} from "./breadcrumb.utils";
+import { SpaceTreeNode } from "@/features/page/tree/types.ts";
+import { IPage } from "@/features/page/types/page.types.ts";
+
+// Pure selection/mapping behind the breadcrumb (#218): tree-hit prefers the live
+// sidebar tree, tree-miss maps the page's own ancestors, and "no data" returns
+// null so the component keeps its prior state.
+
+function treeNode(id: string, over?: Partial<SpaceTreeNode>): SpaceTreeNode {
+  return {
+    id,
+    slugId: `slug-${id}`,
+    name: `node-${id}`,
+    icon: null,
+    position: "a",
+    hasChildren: false,
+    spaceId: "space-1",
+    parentPageId: null,
+    children: [],
+    ...over,
+  } as SpaceTreeNode;
+}
+
+function ancestorPage(id: string, over?: Partial<IPage>): IPage {
+  return {
+    id,
+    slugId: `slug-${id}`,
+    title: `title-${id}`,
+    icon: "📄",
+    position: "m",
+    spaceId: "space-1",
+    parentPageId: null,
+    hasChildren: true,
+    ...over,
+  } as IPage;
+}
+
+describe("resolveBreadcrumbNodes", () => {
+  it("tree-hit: returns the path found in the live sidebar tree", () => {
+    const child = treeNode("child");
+    const root = treeNode("root", { hasChildren: true, children: [child] });
+    // findBreadcrumbPath walks the tree; the chain ends at the target page.
+    const result = resolveBreadcrumbNodes([root], [ancestorPage("child")], "child");
+
+    expect(result).not.toBeNull();
+    expect(result!.map((n) => n.id)).toEqual(["root", "child"]);
+    // Came from the tree, NOT the ancestor mapping (icon stays the tree's null).
+    expect(result![result!.length - 1].icon).toBeNull();
+  });
+
+  it("tree-miss: maps the page's own ancestors (title->name, hasChildren default)", () => {
+    // Tree has no node for the target page -> findBreadcrumbPath misses.
+    const unrelated = treeNode("unrelated");
+    const ancestors = [
+      ancestorPage("a", { hasChildren: true }),
+      ancestorPage("b", { hasChildren: undefined as any }),
+    ];
+
+    const result = resolveBreadcrumbNodes([unrelated], ancestors, "missing-page");
+
+    expect(result).not.toBeNull();
+    expect(result!.map((n) => n.id)).toEqual(["a", "b"]);
+    // Non-trivial field transform: title -> name.
+    expect(result![0].name).toBe("title-a");
+    // hasChildren defaults to false when the ancestor row omits it.
+    expect(result![1].hasChildren).toBe(false);
+    expect(result![0].hasChildren).toBe(true);
+  });
+
+  it("falls back to ancestors when the tree is empty", () => {
+    const result = resolveBreadcrumbNodes([], [ancestorPage("a")], "a");
+    expect(result!.map((n) => n.id)).toEqual(["a"]);
+  });
+
+  it("returns null when there is no tree hit and no ancestor data", () => {
+    expect(resolveBreadcrumbNodes([], [], "x")).toBeNull();
+    expect(resolveBreadcrumbNodes(undefined, undefined, "x")).toBeNull();
+    expect(resolveBreadcrumbNodes(null, null, "x")).toBeNull();
+  });
+});
+
+describe("computeBreadcrumbState (stale-chain clearing on navigation)", () => {
+  it("uses a freshly resolved chain when available", () => {
+    const child = treeNode("B");
+    const root = treeNode("root", { hasChildren: true, children: [child] });
+    const next = computeBreadcrumbState([root], null, "B", null);
+    expect(next!.map((n) => n.id)).toEqual(["root", "B"]);
+  });
+
+  it("navigating A->B to a page absent from treeData clears the previous A chain (no stale trail)", () => {
+    // Previous chain ends at page A; we are now on page B, which is not yet in
+    // the lazily-built tree and whose ancestors have not loaded.
+    const previous = [treeNode("rootA"), treeNode("A")];
+    const next = computeBreadcrumbState([treeNode("unrelated")], undefined, "B", previous);
+    // Must NOT keep showing A's (clickable) chain.
+    expect(next).toBeNull();
+  });
+
+  it("keeps a chain that already ends at the current page through a transient miss", () => {
+    // We already resolved B once (chain ends at B); a transient miss must not
+    // blank it.
+    const previous = [treeNode("rootB"), treeNode("B")];
+    const next = computeBreadcrumbState([], undefined, "B", previous);
+    expect(next).toBe(previous);
+  });
+
+  it("returns null when nothing resolves and there is no previous chain", () => {
+    expect(computeBreadcrumbState([], undefined, "B", null)).toBeNull();
+  });
+});

apps/client/src/features/page/components/breadcrumbs/breadcrumb.utils.ts

@@ -0,0 +1,61 @@
+import { IPage } from "@/features/page/types/page.types.ts";
+import { SpaceTreeNode } from "@/features/page/tree/types.ts";
+import { findBreadcrumbPath, pageToTreeNode } from "@/features/page/tree/utils";
+
+/**
+ * Pure selection/mapping for the breadcrumb nodes (#218). Three branches:
+ *   1. tree-hit  — the lazily-built sidebar tree already contains this page's
+ *      ancestor chain, so prefer it (stays live with sidebar renames/moves).
+ *   2. tree-miss — fall back to the page's own ancestor data so a deep page
+ *      resolves immediately instead of rendering a blank breadcrumb for seconds
+ *      while the tree backfills. Mapped through the canonical `pageToTreeNode`
+ *      (title -> name, hasChildren defaulted to false).
+ *   3. neither   — no data yet, return null (the caller decides whether to keep
+ *      a prior chain via computeBreadcrumbState).
+ */
+export function resolveBreadcrumbNodes(
+  treeData: SpaceTreeNode[] | null | undefined,
+  ancestors: IPage[] | null | undefined,
+  pageId: string,
+): SpaceTreeNode[] | null {
+  if (treeData && treeData.length > 0) {
+    const breadcrumb = findBreadcrumbPath(treeData, pageId);
+    if (breadcrumb) {
+      return breadcrumb;
+    }
+  }
+
+  if (ancestors && ancestors.length > 0) {
+    return ancestors.map((page) =>
+      pageToTreeNode(page, { hasChildren: page.hasChildren ?? false }),
+    );
+  }
+
+  return null;
+}
+
+/**
+ * Decide the next breadcrumb state, given the previous one. When a chain
+ * resolves (#218) it always wins. When nothing resolves yet, a stale chain from
+ * a previously-viewed page must be CLEARED rather than left showing the wrong,
+ * clickable trail (the reverse regression of the original blank-breadcrumb fix
+ * when navigating A -> B to a deep page not yet in the lazily-built tree). The
+ * one chain we keep through a transient miss is one that already ends at the
+ * current page — that means we already resolved THIS page, so keeping it avoids
+ * a needless blank flash without ever showing the previous page's chain.
+ */
+export function computeBreadcrumbState(
+  treeData: SpaceTreeNode[] | null | undefined,
+  ancestors: IPage[] | null | undefined,
+  pageId: string,
+  previous: SpaceTreeNode[] | null,
+): SpaceTreeNode[] | null {
+  const resolved = resolveBreadcrumbNodes(treeData, ancestors, pageId);
+  if (resolved) {
+    return resolved;
+  }
+
+  const previousEndsAtCurrentPage =
+    previous != null && previous[previous.length - 1]?.id === pageId;
+  return previousEndsAtCurrentPage ? previous : null;
+}

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.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 +79,46 @@ 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,
+      });
+      // Best-effort: warm the page's Yjs document into IndexedDB.
+      await warmPageYdoc(node.id, getCollaborationUrl(), collabQuery?.token);
+
+      if (result.ok) {
+        notifications.show({ message: t("Page is now available offline") });
+      } else {
+        // Partial warm — the page may still be partly usable offline, but some
+        // queries 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); `result.failed` carries them.
+        notifications.show({
+          message: `${t("Failed to make page available offline")}: ${result.failed.join(", ")}`,
+          color: "red",
+        });
+      }
+    } catch (err) {
+      // makePageAvailableOffline no longer throws, but warmPageYdoc and other
+      // unexpected failures stay guarded here. Log the raw error and surface the
+      // real cause to the user instead of a bare generic string (AGENTS.md).
+      console.error("handleMakeAvailableOffline failed", err);
+      const reason =
+        (err as { response?: { data?: { message?: string } } })?.response?.data
+          ?.message ?? (err instanceof Error ? err.message : String(err));
+      notifications.show({
+        message: `${t("Failed to make page available offline")}: ${reason}`,
+        color: "red",
+      });
+    }
+  };
 
   const handleToggleTemplate = async () => {
     const next = !isTemplate;
@@ -228,6 +275,17 @@ 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/share/components/share-alias-section.test.tsx

@@ -0,0 +1,149 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent, waitFor } from "@testing-library/react";
+import { MantineProvider } from "@mantine/core";
+import type { IShareAlias } from "@/features/share/types/share.types";
+
+// matchMedia / storage are stubbed globally in vitest.setup.ts.
+
+// The mutation + query hooks reach react-query/network; the availability probe
+// hits the API. Stub them so the section renders in isolation and we can drive
+// the exact branches (taken name -> hint, 409 -> reassign modal).
+const setMutateAsync = vi.fn();
+let currentAlias: IShareAlias | null = null;
+let availabilityResult: {
+  valid: boolean;
+  available: boolean;
+  currentPageId: string | null;
+} = { valid: true, available: true, currentPageId: null };
+
+vi.mock("@/features/share/queries/share-query.ts", () => ({
+  useShareAliasForPageQuery: () => ({ data: currentAlias }),
+  useSetShareAliasMutation: () => ({
+    mutateAsync: setMutateAsync,
+    isPending: false,
+  }),
+  useRemoveShareAliasMutation: () => ({
+    mutateAsync: vi.fn(),
+    isPending: false,
+  }),
+}));
+
+vi.mock("@/features/share/services/share-service.ts", () => ({
+  checkShareAliasAvailability: vi.fn(async () => availabilityResult),
+}));
+
+import ShareAliasSection from "./share-alias-section";
+
+const aliasRow = (alias: string, pageId: string): IShareAlias => ({
+  id: `alias-${alias}`,
+  workspaceId: "ws-1",
+  alias,
+  pageId,
+  creatorId: "user-1",
+  createdAt: new Date().toISOString(),
+  updatedAt: new Date().toISOString(),
+});
+
+function renderSection(pageId = "page-Y") {
+  return render(
+    <MantineProvider>
+      <ShareAliasSection pageId={pageId} readOnly={false} />
+    </MantineProvider>,
+  );
+}
+
+describe("ShareAliasSection — taken-name handling is never a dead end", () => {
+  beforeEach(() => {
+    setMutateAsync.mockReset();
+    currentAlias = null;
+    availabilityResult = { valid: true, available: true, currentPageId: null };
+  });
+
+  it("shows a 'will move it here' HINT (not a terminal error) when the name belongs to another page, and keeps Save enabled", async () => {
+    // Page Y already owns "bee"; the user retypes a name owned by page X.
+    currentAlias = aliasRow("bee", "page-Y");
+    availabilityResult = {
+      valid: true,
+      available: false,
+      currentPageId: "page-X",
+    };
+
+    renderSection("page-Y");
+    const input = screen.getByPlaceholderText("my-page") as HTMLInputElement;
+    fireEvent.change(input, { target: { value: "test2" } });
+
+    // The reassign hint replaces the old dead-end red error.
+    await waitFor(
+      () =>
+        expect(
+          screen.getByText(
+            "This address is in use. Saving will move it to this page.",
+          ),
+        ).toBeDefined(),
+      { timeout: 2000 },
+    );
+    // The old terminal "already in use" error must NOT be shown.
+    expect(screen.queryByText("This address is already in use")).toBeNull();
+
+    // Save stays enabled so the confirm-reassign flow can run.
+    const saveBtn = screen.getByRole("button", {
+      name: "Save",
+    }) as HTMLButtonElement;
+    expect(saveBtn.disabled).toBe(false);
+  });
+
+  it("opens the reassign-confirm modal on a 409 ALIAS_REASSIGN_REQUIRED (path forward, not a dead end)", async () => {
+    currentAlias = aliasRow("bee", "page-Y");
+    availabilityResult = {
+      valid: true,
+      available: false,
+      currentPageId: "page-X",
+    };
+    // The server rejects the un-confirmed save asking the client to confirm.
+    setMutateAsync.mockRejectedValueOnce({
+      status: 409,
+      response: {
+        status: 409,
+        data: {
+          code: "ALIAS_REASSIGN_REQUIRED",
+          currentPageId: "page-X",
+          currentPageTitle: "Alias Test Page X",
+        },
+      },
+    });
+
+    renderSection("page-Y");
+    const input = screen.getByPlaceholderText("my-page") as HTMLInputElement;
+    fireEvent.change(input, { target: { value: "test2" } });
+
+    const saveBtn = screen.getByRole("button", {
+      name: "Save",
+    }) as HTMLButtonElement;
+    await waitFor(() => expect(saveBtn.disabled).toBe(false), {
+      timeout: 2000,
+    });
+    fireEvent.click(saveBtn);
+
+    // First save sent WITHOUT confirmReassign.
+    await waitFor(() =>
+      expect(setMutateAsync).toHaveBeenCalledWith(
+        expect.objectContaining({ alias: "test2", confirmReassign: false }),
+      ),
+    );
+
+    // The "Move custom address?" confirm modal must appear (the path forward).
+    await waitFor(() =>
+      expect(screen.getByText("Move custom address?")).toBeDefined(),
+    );
+    expect(screen.getByRole("button", { name: "Move here" })).toBeDefined();
+
+    // Confirming retries WITH confirmReassign: true.
+    setMutateAsync.mockResolvedValueOnce(aliasRow("test2", "page-Y"));
+    fireEvent.click(screen.getByRole("button", { name: "Move here" }));
+    await waitFor(() =>
+      expect(setMutateAsync).toHaveBeenCalledWith(
+        expect.objectContaining({ alias: "test2", confirmReassign: true }),
+      ),
+    );
+  });
+});

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

@@ -120,8 +120,13 @@ export default function ShareAliasSection({
   };
 
   const showInvalid = normalized.length > 0 && !isValid;
-  const showTaken =
-    isValid && !unchanged && availability && !availability.available;
+  // The typed name is already in use by ANOTHER page. This is NOT a dead end:
+  // hitting Save triggers the server's 409 `ALIAS_REASSIGN_REQUIRED` and opens
+  // the "Move custom address?" confirm modal that retargets the address here.
+  // So surface it as an informational hint (not a terminal red error) and keep
+  // Save enabled, instead of looking like the address is unusable.
+  const reassignable =
+    isValid && !unchanged && !!availability && !availability.available;
 
   // The slug prefix (e.g. "docs.example.com/l/") is static for the session.
   const prefixLabel = aliasPrefixLabel();
@@ -198,9 +203,12 @@ export default function ShareAliasSection({
         error={
           showInvalid
             ? t("Use 2-60 lowercase letters, digits and hyphens")
-            : showTaken
-              ? t("This address is already in use")
-              : undefined
+            : undefined
+        }
+        description={
+          reassignable
+            ? t("This address is in use. Saving will move it to this page.")
+            : undefined
         }
       />
 

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

@@ -0,0 +1,74 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent, waitFor } from "@testing-library/react";
+import { MantineProvider } from "@mantine/core";
+import { MemoryRouter } from "react-router-dom";
+
+// matchMedia / storage are stubbed globally in vitest.setup.ts.
+
+// Enabling a public share must NOT silently expose the whole sub-tree (#216):
+// the create call defaults includeSubPages to false. This was a one-literal,
+// security-relevant default with no test — lock it.
+
+const createMutateAsync = vi.fn(async () => ({}));
+const deleteMutateAsync = vi.fn(async () => ({}));
+
+// No existing share for this page (toggle starts OFF).
+let shareData: any = undefined;
+
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (key: string) => key }),
+}));
+
+vi.mock("@/features/share/queries/share-query.ts", () => ({
+  useCreateShareMutation: () => ({ mutateAsync: createMutateAsync }),
+  useDeleteShareMutation: () => ({ mutateAsync: deleteMutateAsync }),
+  useUpdateShareMutation: () => ({ mutateAsync: vi.fn() }),
+  useShareForPageQuery: () => ({ data: shareData }),
+}));
+
+vi.mock("@/features/page/queries/page-query.ts", () => ({
+  usePageQuery: () => ({ data: { id: "page-1", title: "Doc" } }),
+}));
+
+vi.mock("@/features/space/queries/space-query.ts", () => ({
+  useSpaceQuery: () => ({ data: { settings: {} } }),
+}));
+
+import ShareModal from "./share-modal";
+
+function renderModal() {
+  return render(
+    <MemoryRouter>
+      <MantineProvider>
+        <ShareModal readOnly={false} />
+      </MantineProvider>
+    </MemoryRouter>,
+  );
+}
+
+describe("ShareModal — enabling a share defaults includeSubPages to false (#216)", () => {
+  beforeEach(() => {
+    createMutateAsync.mockClear();
+    deleteMutateAsync.mockClear();
+    shareData = undefined;
+  });
+
+  it("creates the share with includeSubPages: false when the user turns it on", async () => {
+    renderModal();
+
+    // Open the share popover.
+    fireEvent.click(screen.getByRole("button", { name: "Share" }));
+
+    // The "Share to web" toggle is the only switch in the not-yet-shared state.
+    const toggle = await screen.findByRole("switch");
+    fireEvent.click(toggle);
+
+    await waitFor(() => expect(createMutateAsync).toHaveBeenCalledTimes(1));
+    expect(createMutateAsync).toHaveBeenCalledWith(
+      expect.objectContaining({
+        pageId: "page-1",
+        includeSubPages: false,
+      }),
+    );
+  });
+});

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

@@ -73,7 +73,10 @@ export default function ShareModal({ readOnly }: ShareModalProps) {
       if (value) {
         await createShareMutation.mutateAsync({
           pageId: pageId,
-          includeSubPages: true,
+          // Opt-in: enabling a share must NOT silently expose the whole
+          // sub-tree (#216). Sub-pages are shared only when the user turns on
+          // the dedicated "Include sub-pages" toggle.
+          includeSubPages: false,
           searchIndexing: false,
         });
       } else if (share && share.id) {

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

@@ -35,9 +35,17 @@ export interface ISharedItem extends IShare {
   };
 }
 
-export interface ISharedPage extends IShare {
-  page: IPage;
-  share: IShare & {
+// The `/shares/page-info` (anonymous) response. Mirrors the server-side
+// PublicSharePayload allowlist (#218): the server trims `page`/`share` to these
+// fields exactly, so the client type must not over-declare internal metadata it
+// will never receive. Keep this in sync with share-public-payload.ts.
+export interface ISharedPage {
+  page: Pick<IPage, "id" | "slugId" | "title" | "icon" | "content">;
+  share: {
+    id: string;
+    key: string;
+    includeSubPages: boolean;
+    searchIndexing: boolean;
     level: number;
     sharedPage: { id: string; slugId: string; title: string; icon: string };
   };
@@ -73,6 +81,10 @@ export type IUpdateShare = ICreateShare & { shareId: string; pageId?: string };
 
 export interface IShareInfoInput {
   pageId: string;
+  // The share id/key from the `/share/:shareId/p/:slug` URL. When present the
+  // server binds content access to this exact share (#218): a forged/mismatched
+  // shareId 404s instead of rendering the page off its slug alone.
+  shareId?: string;
 }
 
 // Vanity /l/:alias pointer.

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/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/pages/share/shared-page.tsx

@@ -24,6 +24,9 @@ export default function SharedPage() {
 
   const { data, isLoading, isError, error } = useSharePageQuery({
     pageId: extractPageSlugId(pageSlug),
+    // Forward the URL's shareId so the server binds content to this share
+    // (#218): a forged shareId 404s instead of rendering the page off its slug.
+    shareId,
   });
 
   const sharedTreeData = useAtomValue(sharedTreeDataAtom);

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 {
@@ -149,6 +152,70 @@ 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

@@ -59,6 +59,7 @@ 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({
@@ -143,6 +144,34 @@ 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

@@ -205,6 +205,32 @@ 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'),
+      });
+
+      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();
+    },
+  );
+
   // persist-1 — when every attempt fails the hook must NOT report a phantom
   // success: no "page.updated" badge broadcast and no history snapshot for
   // content that was never written.

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

@@ -9,6 +9,7 @@ import * as Y from 'yjs';
 import { Injectable, Logger } from '@nestjs/common';
 import { TiptapTransformer } from '@hocuspocus/transformer';
 import {
+  buildTitleSeedYdoc,
   getPageId,
   isEmptyParagraphDoc,
   jsonToText,
@@ -116,6 +117,10 @@ 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 +132,193 @@ 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 +336,34 @@ 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
@@ -205,11 +397,80 @@ 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;
+          }
+
           let contributorIds = undefined;
           try {
             const existingContributors = page.contributorIds || [];
@@ -227,29 +488,22 @@ 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 +521,27 @@ 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 +562,8 @@ 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 +581,20 @@ 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);

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),
+      );
+    }
+  }
+}