feat: Add presence heartbeat for Matrix online status

- matrix-gateway: POST /internal/matrix/presence/online endpoint
- usePresenceHeartbeat hook with activity tracking
- Auto away after 5 min inactivity
- Offline on page close/visibility change
- Integrated in MatrixChatRoom component

node_modules/ws/wrapper.mjs

@@ -0,0 +1,8 @@
+import createWebSocketStream from './lib/stream.js';
+import Receiver from './lib/receiver.js';
+import Sender from './lib/sender.js';
+import WebSocket from './lib/websocket.js';
+import WebSocketServer from './lib/websocket-server.js';
+
+export { createWebSocketStream, Receiver, Sender, WebSocket, WebSocketServer };
+export default WebSocket;