Refine prompt_template_source: lmms-eval/VLMEvalKit canonical citations

metadata.json

@@ -33,8 +33,9 @@
         }
       },
       "prompt_template_source": {
-        "origin": "fallback",
-        "reference": "T2"
+        "origin": "official",
+        "reference": "https://github.com/open-compass/VLMEvalKit/blob/main/vlmeval/dataset/image_vqa.py (WildVision-Bench — judge-scored; bare question)",
+        "notes": "WildVision-Bench judge-scored eval: bare question per the official WildVision-Bench paper."
       }
     }
   }