fix(offline): address PR #120 review (comment 2513)

CHANGELOG: stop presenting the service-worker API cache as an active offline
store (/api is NetworkOnly) — describe it as a defensive purge of the legacy
api-get-cache from older clients; add an explicit upgrade note that the new CORS
allowlist rejects previously-allowed cross-domain REST clients until their origin
is added to CORS_ALLOWED_ORIGINS.

test(offline): cover make-offline ancestor-walk + dedup — a real-ancestor case
exercising the ancestorId===pageId guard (page warmed once), the dedup of
repeated tree failures into a single "tree" label, and the "breadcrumbs" label
when the breadcrumbs lookup rejects.

test(auth): cover clearOfflineCache in handleLogout — purged exactly once before
window.location.replace, and a thrown purge error does not block the redirect.

conventions: use pageKeys.detail() instead of raw ["pages", …] literals in
title-editor and use-page-collab-providers.

cleanup: remove the dead emit() in title-editor (the gateway ignores it; the
cross-user tree refresh is server-side via the Yjs title fragment); drop the
trivial Array.isArray(tiptapExtensions) test (schema is exercised transitively).

refactor: extract the shared page.<id> Yjs doc-name convention into
pageYdocName()/PAGE_YDOC_NAME_PREFIX so the editor providers, offline warm, and
offline purge can no longer drift apart.

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

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

@@ -11,10 +11,9 @@ import {
   pageEditorAtom,
   titleEditorAtom,
 } from "@/features/editor/atoms/editor-atoms";
-import { updatePageData } 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 { Collaboration } from "@tiptap/extension-collaboration";
 import { shouldPropagateTitleChange } from "@/features/editor/title-collab";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
@@ -48,7 +47,6 @@ export function TitleEditor({
   const { t } = useTranslation();
   const pageEditor = useAtomValue(pageEditorAtom);
   const [, setTitleEditor] = useAtom(titleEditorAtom);
-  const emit = useQueryEmit();
   const navigate = useNavigate();
   const currentPageEditMode = useAtomValue(currentPageEditModeAtom);
 
@@ -145,8 +143,8 @@ export function TitleEditor({
     });
 
     const page =
-      queryClient.getQueryData<IPage>(["pages", slugId]) ??
-      queryClient.getQueryData<IPage>(["pages", pageId]);
+      queryClient.getQueryData<IPage>(pageKeys.detail(slugId)) ??
+      queryClient.getQueryData<IPage>(pageKeys.detail(pageId));
     if (!page) return;
 
     const updatedPage: IPage = { ...page, title: titleText };
@@ -165,8 +163,11 @@ export function TitleEditor({
     };
 
     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);
-    emit(event);
   }, 500);
 
   useEffect(() => {