feat: add Docker health-state HTTP endpoint for Swarm Health Watchdog

- Python HTTP server on 0.0.0.0:18809
- GET /health -> all monitored containers (JSON)
- GET /health/<name> -> single container
- Monitors: brave-search, kokoro-tts, litellm, litellm-db, n8n-agent, searxng, whisper-server
- Returns status, health, restart count via docker inspect
- systemd user service for auto-start

Task: t_461f71fe

openclaw/devices/paired.json

@@ -3,8 +3,8 @@
     "deviceId": "ad0ebece2493ecaf2336b939a2cc27e65261695c8c8725416e1d349da02a14d5",
     "publicKey": "zezYCyurUtpYNt9j6bBc5Cz5xFVdnknXzhoCVAOFiwY",
     "platform": "linux",
-    "clientId": "gateway-client",
-    "clientMode": "backend",
+    "clientId": "cli",
+    "clientMode": "cli",
     "role": "operator",
     "roles": [
       "operator"
@@ -40,8 +40,7 @@
       }
     },
     "createdAtMs": 1772478478331,
-    "approvedAtMs": 1772478926904,
-    "displayName": "agent"
+    "approvedAtMs": 1772478926904
   },
   "5edabd97839bb827cf4a7e1bdbbf52d3bdc14ee3ed6cd4488dea64165a343a96": {
     "deviceId": "5edabd97839bb827cf4a7e1bdbbf52d3bdc14ee3ed6cd4488dea64165a343a96",
@@ -111,7 +110,7 @@
           "operator.pairing"
         ],
         "createdAtMs": 1772563930487,
-        "lastUsedAtMs": 1774811304607
+        "lastUsedAtMs": 1777577695518
       }
     },
     "createdAtMs": 1772563930487,
@@ -183,7 +182,7 @@
           "operator.write"
         ],
         "createdAtMs": 1774546161801,
-        "lastUsedAtMs": 1774815544302
+        "lastUsedAtMs": 1776198489189
       }
     },
     "createdAtMs": 1774546161801,
@@ -224,7 +223,8 @@
           "operator.read",
           "operator.write"
         ],
-        "createdAtMs": 1774546959027
+        "createdAtMs": 1774546959027,
+        "lastUsedAtMs": 1777595759200
       }
     },
     "createdAtMs": 1774546959027,