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/@nodelib/fs.scandir/out/providers/common.js

@@ -0,0 +1,13 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.joinPathSegments = void 0;
+function joinPathSegments(a, b, separator) {
+    /**
+     * The correct handling of cases when the first segment is a root (`/`, `C:/`) or UNC path (`//?/C:/`).
+     */
+    if (a.endsWith(separator)) {
+        return a + b;
+    }
+    return a + separator + b;
+}
+exports.joinPathSegments = joinPathSegments;