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/slash/index.js

@@ -0,0 +1,11 @@
+'use strict';
+module.exports = path => {
+	const isExtendedLengthPath = /^\\\\\?\\/.test(path);
+	const hasNonAscii = /[^\u0000-\u0080]+/.test(path); // eslint-disable-line no-control-regex
+
+	if (isExtendedLengthPath || hasNonAscii) {
+		return path;
+	}
+
+	return path.replace(/\\/g, '/');
+};