Implement Monlet MVP stack and UI updates

examples/event-batch.json

@@ -10,7 +10,6 @@
       "duration_ms": 42,
       "output": "/ 18% used (180G/1.0T)",
       "output_truncated": false,
-      "notification_owner": "server",
       "incident_key": "host-01.prod:disk_root"
     },
     {
@@ -22,7 +21,6 @@
       "duration_ms": 1503,
       "output": "could not connect to server: Connection refused",
       "output_truncated": false,
-      "notification_owner": "server",
       "incident_key": "host-01.prod:postgres_up"
     }
   ]

examples/heartbeat.json

@@ -2,9 +2,12 @@
   "agent_id": "host-01.prod",
   "observed_at": "2026-05-26T12:00:00Z",
   "hostname": "host-01.prod.example.com",
-  "version": "0.1.0",
-  "mode": "push_only",
+  "features": {
+    "push": true,
+    "metrics": false
+  },
   "labels": {
+    "monlet_agent_version": "0.1.0",
     "env": "prod",
     "region": "eu-central-1",
     "role": "api"