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/components/message/content/AudioContent.tsx

@@ -99,9 +99,21 @@ export function AudioContent({
   const [playbackSpeed, setPlaybackSpeed] = useState<0.75 | 1 | 1.5 | 2>(1);
 
   useEffect(() => {
-    if (audioRef.current) {
-      audioRef.current.playbackRate = playbackSpeed;
-    }
+    const audio = audioRef.current;
+    if (!audio) return undefined;
+    const applyRate = () => {
+      audio.playbackRate = playbackSpeed;
+    };
+    // Apply immediately, and re-apply whenever the media element (re)loads a new
+    // source — e.g. after async decrypt swaps in the blob URL — since the browser
+    // resets playbackRate to 1 on load, discarding the user's speed choice.
+    applyRate();
+    audio.addEventListener('loadedmetadata', applyRate);
+    audio.addEventListener('play', applyRate);
+    return () => {
+      audio.removeEventListener('loadedmetadata', applyRate);
+      audio.removeEventListener('play', applyRate);
+    };
   }, [playbackSpeed]);
 
   const SPEED_STEPS: Array<0.75 | 1 | 1.5 | 2> = [0.75, 1, 1.5, 2];