fix: bump matrixRTC maxListeners to suppress MaxListenersExceededWarning

Each RoomNavItem subscribes to session_started/session_ended on the
MatrixRTCSessionManager, one per visible room. The default limit of 10
fires a spurious warning when 11+ rooms are in the sidebar. Listeners
are properly cleaned up — this is not a real leak.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/client/initMatrix.ts

@@ -48,6 +48,8 @@ export const initClient = async (session: Session): Promise<MatrixClient> => {
   await mx.initRustCrypto();
 
   mx.setMaxListeners(50);
+  // Each RoomNavItem subscribes to session_started/session_ended; one listener per visible room.
+  mx.matrixRTC.setMaxListeners(100);
 
   return mx;
 };