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/hooks/useSoundboardPacks.ts

@@ -1,5 +1,5 @@
 import { Room } from 'matrix-js-sdk';
-import { useCallback, useMemo, useState } from 'react';
+import { useCallback, useEffect, useMemo, useState } from 'react';
 import { AccountDataEvent } from '../../types/matrix/accountData';
 import { StateEvent } from '../../types/matrix/room';
 import {
@@ -79,6 +79,13 @@ export const useRoomSoundboardPack = (room: Room, stateKey: string): SoundboardP
   const mx = useMatrixClient();
   const [roomPack, setRoomPack] = useState(() => getRoomSoundboardPack(room, stateKey));
 
+  // Resync when the room/stateKey arg changes — the useState initializer only
+  // runs on mount, so without this a re-target (e.g. a different room) kept
+  // showing the first room's pack.
+  useEffect(() => {
+    setRoomPack(getRoomSoundboardPack(room, stateKey));
+  }, [room, stateKey]);
+
   useStateEventCallback(
     mx,
     useCallback(
@@ -102,6 +109,11 @@ export const useRoomSoundboardPacks = (room: Room): SoundboardPack[] => {
   const mx = useMatrixClient();
   const [roomPacks, setRoomPacks] = useState(() => getRoomSoundboardPacks(room));
 
+  // Resync on room change (see useRoomSoundboardPack).
+  useEffect(() => {
+    setRoomPacks(getRoomSoundboardPacks(room));
+  }, [room]);
+
   useStateEventCallback(
     mx,
     useCallback(
@@ -124,6 +136,12 @@ export const useRoomsSoundboardPacks = (rooms: Room[]): SoundboardPack[] => {
   const mx = useMatrixClient();
   const [roomPacks, setRoomPacks] = useState(() => rooms.flatMap(getRoomSoundboardPacks));
 
+  // Resync when the room list changes (callers pass a memoized array, so this
+  // fires only on an actual change — see useRoomSoundboardPack).
+  useEffect(() => {
+    setRoomPacks(rooms.flatMap(getRoomSoundboardPacks));
+  }, [rooms]);
+
   useStateEventCallback(
     mx,
     useCallback(