fix: add empty-ID guard to delete_model to prevent wiping engine models directory

src/voxkit/storage/models.py

@@ -401,8 +401,12 @@ def delete_model(engine_id: str, model_id: str) -> Tuple[bool, str]:
     Notes:
         - This operation is irreversible
         - Removes the entire model directory tree
+        - Validates that engine_id and model_id are not empty before proceeding
     """
 
+    if not engine_id or not model_id:
+        return False, "Engine ID and Model ID cannot be empty."
+
     print(f"Attempting to delete model: engine_id={engine_id}, model_id={model_id}")
     model_path = _get_model_root(engine_id, model_id)
 

tests/storage/test_models.py

@@ -297,6 +297,29 @@ def test_delete_model_invalid_engine(self, monkeypatch):
             assert success is False
             assert "not found" in msg
 
+        def test_delete_model_empty_ids(self, monkeypatch):
+            from voxkit.storage import models
+            from voxkit.storage.models import delete_model
+
+            monkeypatch.setattr(models, "get_storage_root", mock_get_storage_root)
+
+            engine_id = ENGINE_IDS[0]
+
+            # Empty model_id
+            success, msg = delete_model(engine_id=engine_id, model_id="")
+            assert success is False
+            assert "cannot be empty" in msg
+
+            # Empty engine_id
+            success, msg = delete_model(engine_id="", model_id="some_model_id")
+            assert success is False
+            assert "cannot be empty" in msg
+
+            # Both empty
+            success, msg = delete_model(engine_id="", model_id="")
+            assert success is False
+            assert "cannot be empty" in msg
+
     class TestGetModelMetadata:
         def test_get_model_metadata_success(self, monkeypatch):
             from voxkit.storage import models