feat: auto-recovery pyrealsense2 stuck via healthcheck + autoheal

Sostituisce il healthcheck banale (urlopen /api/health) con uno che
fallisce quando camera_open != true, e aggiunge il container willfarrell/autoheal
che restarta il backend quando Docker lo marca unhealthy. Recovery <1min
da SDK stuck senza intervento SSH.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -40,11 +40,43 @@ services:
         condition: service_healthy
         required: false
     restart: unless-stopped
+    labels:
+      # autoheal monitora SOLO i container con questa label = true
+      autoheal: "true"
     healthcheck:
-      test: ["CMD", "python3", "-c", "import urllib.request; urllib.request.urlopen('http://localhost:8878/api/health')"]
-      interval: 10s
+      # Healthcheck "vero": fallisce se camera_open != true.
+      # Usa /api/health (pubblico, no API key) che già ritorna camera_open.
+      # 4 retry × 15s ⇒ ~1 min di stato cattivo prima dell'autoheal restart.
+      test:
+        - CMD
+        - python3
+        - -c
+        - |
+          import urllib.request, json, sys
+          try:
+              r = urllib.request.urlopen('http://localhost:8878/api/health', timeout=3)
+              d = json.loads(r.read())
+              sys.exit(0 if d.get('data', {}).get('camera_open') else 1)
+          except Exception:
+              sys.exit(1)
+      interval: 15s
       timeout: 5s
-      retries: 3
+      retries: 4
+      start_period: 30s
+
+  # -- Autoheal -------------------------------
+  # Monitora i container con label `autoheal=true` e li restarta automaticamente
+  # quando Docker li marca "unhealthy". Risolve il caso "pyrealsense2 SDK stuck".
+  autoheal:
+    image: willfarrell/autoheal:latest
+    container_name: autoheal-d435
+    restart: always
+    environment:
+      AUTOHEAL_CONTAINER_LABEL: autoheal
+      AUTOHEAL_INTERVAL: 10
+      AUTOHEAL_START_PERIOD: 30
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock:ro
 
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