Tighten prompt_template_source.notes: explicit 5-tier classification per 2026-06-01 priority rules

metadata.json

@@ -54,7 +54,7 @@
       "prompt_template_source": {
         "origin": "official",
         "reference": "https://github.com/open-compass/VLMEvalKit/blob/main/vlmeval/dataset/image_mcq.py (ImageMCQDataset.build_prompt — canonical MCQ trailer with options bullets)",
-        "notes": "VLMEvalKit ImageMCQDataset.build_prompt; We-Math is evaluated via VLMEvalKit's standard MCQ flow."
+        "notes": "Tier 3: VLMEvalKit ImageMCQDataset.build_prompt; We-Math is evaluated via VLMEvalKit's standard MCQ flow."
       }
     }
   }