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

scripts/stop-city-space-services.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+# Stop City and Space services
+
+set -e
+
+echo "🛑 Stopping DAARION City + Space Services..."
+
+docker-compose -f docker-compose.city-space.yml down
+
+echo "✅ Services stopped!"
+
+
+
+