Add a handler to make the structure of validation errors consistent.

tests/test_general_endpoint.py

@@ -89,7 +89,7 @@ class TestGeneralEndpoint:
             "entities": []
         }
         response = api_client.post(f"{BASE_URL}/general", json=payload)
-        assert response.status_code == 422  # Pydantic validation error
+        assert response.status_code == 400
 
     def test_error_empty_texts_list(self, api_client):
         """Test error with an empty texts list"""
@@ -109,7 +109,7 @@ class TestGeneralEndpoint:
             "threshold": threshold
         }
         response = api_client.post(f"{BASE_URL}/general", json=payload)
-        assert response.status_code == 422
+        assert response.status_code == 400
 
     @pytest.mark.parametrize("threshold", [0.0, 0.5, 1.0])
     def test_valid_threshold_range(self, api_client, threshold):

tests/test_relation_extraction_endpoint.py

@@ -73,7 +73,7 @@ class TestRelationExtractionEndpoint:
             "relations": []
         }
         response = api_client.post(f"{BASE_URL}/relation-extraction", json=payload)
-        assert response.status_code == 422
+        assert response.status_code == 400
 
     def test_error_both_text_and_texts(self, api_client):
         """Test error when both text and texts are present"""