{
  "ok": false,
  "skill_id": "geometry_foundations.chamfers",
  "lane": "tool_evidence",
  "status": "infrastructure_retry",
  "retryable": true,
  "infrastructure_failure": true,
  "infrastructure_failures": 2,
  "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, project_steps, safe_knowledge_gate, unknown_source_quarantine\",\n  \"retryable\": true,\n  \"infrastructure_failure\": true,\n  \"output_contract\": \"academy_round_json_v6\",\n  \"exam_round\": 3,\n  \"raw_answer\": \"{\\n  \\\"project_steps\\\": [\\n    \\\"Define a rectangular prism base with explicit origin (0,0,0) and dimensions in millimeter",
  "evidence": "/SHiREVault/SHiREAcademy/Practice/geometry_foundations/chamfers/20260801T035456325370Z"
}