fix syntax error

src/model_utils.py

@@ -70,7 +70,7 @@ def save_model(model, user_model_name, metrics_result_single=None):
         login(token=os.environ["HF_TOKEN"])
 
     timestamp = datetime.now().strftime("%y%m%d_%H%M%S")
-    filename = f"{timestamp}{st.session_state.get("target_col", "UNKNOWN")[0]}_{user_model_name}_single"
+    filename = f"{timestamp}{st.session_state.get('target_col', 'UNKNOWN')[0]}_{user_model_name}_single"
 
     # Prepare model dict (same as before)
     model_data = {
@@ -142,7 +142,7 @@ def save_model_ensemble(models, user_model_name, best_iterations=None, fold_scor
         login(token=os.environ["HF_TOKEN"])
 
     timestamp = datetime.now().strftime("%y%m%d_%H%M%S")
-    filename = f"{timestamp}{st.session_state.get("target_col", "UNKNOWN")[0]}_{user_model_name}_ensemble"
+    filename = f"{timestamp}{st.session_state.get('target_col', 'UNKNOWN')[0]}_{user_model_name}_ensemble"
 
     ensemble_data = {
         "timestamp": timestamp,