Update mtdna_backend.py

mtdna_backend.py

@@ -579,6 +579,7 @@ def save_user_usage(usage_dict):
 
         import tempfile
         tmp_path = os.path.join(tempfile.gettempdir(), "user_usage_log.json")
+        print("💾 Saving this usage dict:", usage_dict)
         with open(tmp_path, "w") as f:
             json.dump(usage_dict, f, indent=2)