fix(wave-2): audit fixes — account-data races, search-cache wipe, export, media

Web fixes from the Wave-2 bug-hunt (findings in LOTUS_TODO):
- F1 (security): wipe the decrypted-plaintext search index on SERVER-FORCED
  logout too (token expiry / remote sign-out) — only manual logout did before.
  F4: the delete no longer reports success while onblocked (waits, 3s cap).
- M1/M2 (data-loss): useBookmarks + useUserNotes account-data writes are now
  serialized at MODULE scope (single queue + latestRef per client, echo-driven),
  fixing the cross-instance lost-update clobber (useBookmarks mounts per message
  row, so a per-instance queue was insufficient — caught in review).
- M6: room-history export gets a 200-page cap + Cancel + unmount-abort +
  correct date-range early-break (raw paginated ts). M4: image compression
  skips PNG (was flattening transparency to black), bakes EXIF orientation via
  createImageBitmap, .jpg-renames, and falls back to the original on decode
  failure instead of dropping the file. M5: MediaGallery lightbox opens the
  right item (shared thumb guard). M8: audio speed survives async decrypt.
- Desktop web wiring: D2 badge sums leaf rooms only (space double-count, like
  the favicon fix); D3 useTauriDnd re-hydrates from get_tray_dnd on mount; D5
  updater has a terminal state.

Reviewed; M7 reverted (past-time clamp is an intentional, tested contract).
tsc/eslint/prettier clean, build OK, 678 tests.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/hooks/useTauriUpdater.ts

@@ -38,6 +38,10 @@ export function useTauriUpdater() {
     setStatus({ state: 'installing' });
     try {
       await invoke('install_update');
+      // On a successful install the native side calls app.restart(), so this
+      // resolve is only reached when nothing was installed (no update found) —
+      // don't leave the UI stuck on "installing".
+      setStatus({ state: 'up-to-date' });
     } catch (e) {
       setStatus({ state: 'error', message: String(e) });
     }