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/text-table/example/doubledot.js

@@ -0,0 +1,11 @@
+var table = require('../');
+var t = table([
+    [ '0.1.2' ],
+    [ '11.22.33' ],
+    [ '5.6.7' ],
+    [ '1.22222' ],
+    [ '12345.' ],
+    [ '5555.' ],
+    [ '123' ]
+], { align: [ '.' ] });
+console.log(t);