{"note":"bim_versions 導入後の保存のみ記録 (それ以前は bim_canonical 上書きで履歴なし)","ok":true,"slug":"u-house-sem3e8z3","versions":[{"created_at":"2026-06-10T16:22:44Z","element_count":53,"note":"5軸GA polish 60->87 by M5 (autonomous)","saved_by":"mcp","sha256":"8e9298ed1d662f163448415cff93568cbe05fd9369c34dd9dbe967ec88f17ae8","version":2}]}