{"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-nawcbvhf","versions":[{"created_at":"2026-06-10T18:14:08Z","element_count":72,"note":"5軸GA polish 54->97 by M5 (autonomous)","saved_by":"mcp","sha256":"753fa4c93082676081607042f10bc51dcb75a4a12d3f06ae0066dd737084450e","version":3}]}