Stazioni: camera_url e camera_source, GET /api/stations/by-code/{code} (#72)

Migrazione 020 con le due colonne su stations, campi in modello, schemi e
servizio (validatore http(s) come vision_worker_url), nuova route by-code
dichiarata prima di /{station_id}. Test di migrazione su e giu e di API.

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

src/backend/tests/test_stations_api.py

@@ -430,3 +430,95 @@ async def test_station_vision_worker_url_must_be_http(client: AsyncClient, admin
         json={"vision_worker_url": "ftp://x"},
     )
     assert resp.status_code == 422
+
+
+# --- camera_url / camera_source (#72) ---
+
+async def test_station_camera_fields_roundtrip(client: AsyncClient, admin_user):
+    created = await client.post(
+        "/api/stations", headers=auth_headers(admin_user),
+        json={
+            "code": "ST-CAM", "name": "CAM",
+            "camera_url": " http://127.0.0.1:8765/ ",
+            "camera_source": "  camera:folder  ",
+        },
+    )
+    assert created.status_code == 201, created.text
+    assert created.json()["camera_url"] == "http://127.0.0.1:8765"
+    assert created.json()["camera_source"] == "camera:folder"
+
+    sid = created.json()["id"]
+    read = await client.get(f"/api/stations/{sid}", headers=auth_headers(admin_user))
+    assert read.status_code == 200
+    assert read.json()["camera_url"] == "http://127.0.0.1:8765"
+    assert read.json()["camera_source"] == "camera:folder"
+
+    updated = await client.put(
+        f"/api/stations/{sid}", headers=auth_headers(admin_user),
+        json={"camera_url": "https://cam.example:9000", "camera_source": "camera:ABC123"},
+    )
+    assert updated.status_code == 200
+    assert updated.json()["camera_url"] == "https://cam.example:9000"
+    assert updated.json()["camera_source"] == "camera:ABC123"
+
+    cleared = await client.put(
+        f"/api/stations/{sid}", headers=auth_headers(admin_user),
+        json={"camera_url": "", "camera_source": "   "},
+    )
+    assert cleared.status_code == 200
+    assert cleared.json()["camera_url"] is None
+    assert cleared.json()["camera_source"] is None
+
+
+async def test_station_camera_fields_default_to_null(client: AsyncClient, admin_user):
+    created = await client.post(
+        "/api/stations", headers=auth_headers(admin_user),
+        json={"code": "ST-CN", "name": "CN"},
+    )
+    assert created.status_code == 201
+    assert created.json()["camera_url"] is None
+    assert created.json()["camera_source"] is None
+
+
+async def test_station_camera_url_must_be_http(client: AsyncClient, admin_user):
+    resp = await client.post(
+        "/api/stations", headers=auth_headers(admin_user),
+        json={"code": "ST-CF", "name": "CF", "camera_url": "ftp://x"},
+    )
+    assert resp.status_code == 422
+
+    created = await client.post(
+        "/api/stations", headers=auth_headers(admin_user),
+        json={"code": "ST-CG", "name": "CG"},
+    )
+    resp = await client.put(
+        f"/api/stations/{created.json()['id']}", headers=auth_headers(admin_user),
+        json={"camera_url": "ftp://x"},
+    )
+    assert resp.status_code == 422
+
+
+async def test_station_by_code_returns_station(client: AsyncClient, admin_user):
+    await client.post(
+        "/api/stations", headers=auth_headers(admin_user),
+        json={"code": "ST-BC", "name": "BC", "camera_url": "http://h:1", "camera_source": "camera:folder"},
+    )
+    resp = await client.get("/api/stations/by-code/ST-BC", headers=auth_headers(admin_user))
+    assert resp.status_code == 200, resp.text
+    assert resp.json()["code"] == "ST-BC"
+    assert resp.json()["camera_url"] == "http://h:1"
+    assert resp.json()["camera_source"] == "camera:folder"
+
+
+async def test_station_by_code_unknown_is_404(client: AsyncClient, admin_user):
+    resp = await client.get("/api/stations/by-code/NOPE", headers=auth_headers(admin_user))
+    assert resp.status_code == 404
+
+
+async def test_station_by_code_requires_admin(client: AsyncClient, maker_user, admin_user):
+    await client.post(
+        "/api/stations", headers=auth_headers(admin_user),
+        json={"code": "ST-BA", "name": "BA"},
+    )
+    resp = await client.get("/api/stations/by-code/ST-BA", headers=auth_headers(maker_user))
+    assert resp.status_code == 403