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/fast-glob/out/utils/stream.js

@@ -0,0 +1,17 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.merge = void 0;
+const merge2 = require("merge2");
+function merge(streams) {
+    const mergedStream = merge2(streams);
+    streams.forEach((stream) => {
+        stream.once('error', (error) => mergedStream.emit('error', error));
+    });
+    mergedStream.once('close', () => propagateCloseEventToSources(streams));
+    mergedStream.once('end', () => propagateCloseEventToSources(streams));
+    return mergedStream;
+}
+exports.merge = merge;
+function propagateCloseEventToSources(streams) {
+    streams.forEach((stream) => stream.emit('close'));
+}