Camera di stazione: acquisizione dal frontend e campi admin (#72)

Route POST /measure/api/vision/grab (proxy verso il servizio camera),
get_station_by_code, pulsante «Acquisisci dalla camera», grab() in
vision_execute.js, campi camera_url e camera_source nell'admin stazioni,
traduzioni it/en, extra_hosts host.docker.internal nel compose di sviluppo.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/frontend/flask_app/services/api_client.py

@@ -193,5 +193,9 @@ class APIClient:
         """Return the list of active recipes assigned to the given station."""
         return self.get(f"/api/stations/by-code/{station_code}/recipes")
 
+    def get_station_by_code(self, station_code: str) -> dict[str, Any]:
+        """Return the station with the given code (camera_url / camera_source included)."""
+        return self.get(f"/api/stations/by-code/{station_code}")
+
 
 api_client = APIClient()