fix(state): correct invite re-notify, status clear sync, soundboard resync (DP2/DP3/DP5)

- Invites: seed the notify baseline with the invite count at mount instead
  of 0, so a warm reload (allInvitesAtom populates synchronously from cache
  while SYNCING) no longer re-fires the toast+sound for pre-existing invites.
  Only a genuine increase notifies.
- Status: the cross-device sync effect gated on a truthy presence.status, so
  a remote CLEAR never reset the input or localStorage[STATUS_MSG_KEY] and
  usePresenceUpdater.readStatus() re-sent the stale status. Now mirror an
  empty status as a clear (skipping offline/invisible, which carries an empty
  status_msg by design).
- Soundboard: useState initializers ran once and never recomputed when the
  room/rooms arg changed. Add a resync effect keyed on the arg while keeping
  the live state-event update path.

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

src/app/pages/client/ClientNonUIFeatures.tsx

@@ -134,7 +134,12 @@ function FaviconUpdater() {
 function InviteNotifications() {
   const audioRef = useRef<HTMLAudioElement>(null);
   const invites = useAtomValue(allInvitesAtom);
-  const perviousInviteLen = usePreviousValue(invites.length, 0);
+  // Seed the baseline with the invite count present at mount, NOT 0. allInvitesAtom
+  // populates synchronously from cache on a warm reload while sync is already
+  // SYNCING, so a 0 seed made every pre-existing invite look "new" and re-fired the
+  // toast+sound on each reload. Starting from the current length means only a
+  // genuine INCREASE (a newly-arrived invite) notifies.
+  const perviousInviteLen = usePreviousValue(invites.length, invites.length);
   const mx = useMatrixClient();
 
   const navigate = useNavigate();