{
  "ok": false,
  "skill_id": "geometry_foundations.fillets",
  "lane": "tool_evidence",
  "status": "failed",
  "retryable": false,
  "infrastructure_failure": true,
  "infrastructure_failures": 4,
  "error": "Brain API HTTP 502: {\n  \"ok\": false,\n  \"error\": \"Academy structured output invalid after round-specific canonicalisation: Academy structured output invalid: unexpected fields: acceptance_criteria\",\n  \"retryable\": true,\n  \"infrastructure_failure\": true,\n  \"output_contract\": \"academy_round_json_v6\",\n  \"exam_round\": 3,\n  \"raw_answer\": \"{\\n  \\\"round\\\": 3,\\n  \\\"transfer_project\\\": {\\n    \\\"title\\\": \\\"Household Corner Fillet Transfer\\\",\\n    \\\"goal\\\": \\\"Apply filleting logic to a non-manifold household object model for s",
  "evidence": "/SHiREVault/SHiREAcademy/Practice/geometry_foundations/fillets/20260805T021448653475Z"
}