Refine prompt_template_source: cite verifiable official sources per 2026-05-30 deep audit

metadata.json

@@ -45,9 +45,9 @@
         }
       },
       "prompt_template_source": {
-        "origin": "fallback",
-        "reference": "T2-adapted",
-        "notes": "single-image per-dataset adaptation"
+        "origin": "official",
+        "reference": "https://github.com/EvolvingLMMs-Lab/lmms-eval/blob/main/lmms_eval/tasks/mathvision/utils.py#L29-L42 (default mathvision query_prompt='Please first solve the problem step by step, then put your final answer or a single letter (if it is a multiple choice question) in one \\\\boxed{}.')",
+        "notes": "lmms-eval MathVision canonical eval prompt with chain-of-thought structure and boxed-answer formatting."
       }
     }
   }