fix(image-gen): wrap corrupt-config GET in the 422 error envelope

EvoScientist/model_registry/http_api.py

@@ -658,6 +658,10 @@ class ModelRegistryHttpApi:
             response = await asyncio.to_thread(self._image_generation_response)
         except ModelRegistryError as exc:
             return _error_response(exc, request_id)
+        except ImageGenError as exc:
+            return _error_response(
+                ModelRegistryError(VALIDATION_FAILED, str(exc)), request_id
+            )
         return JSONResponse(response)
 
     async def put_image_generation(self, request: Request) -> Response:

tests/test_image_generation_http.py

@@ -226,3 +226,15 @@ def test_read_scope_cannot_write(client):
         json=_settings_payload(),
     )
     assert response.status_code == 403
+
+
+def test_get_corrupt_section_returns_422_envelope(client, config_path):
+    config_path.write_text(
+        "image_generation:\n  models:\n    - id: gpt-image-2\n      provider: midjourney\n",
+        encoding="utf-8",
+    )
+    response = client.get("/api/image-generation", headers=_admin_headers())
+    assert response.status_code == 422
+    body = response.json()
+    assert body["code"] == "VALIDATION_FAILED"
+    assert "midjourney" not in json.dumps(body)