{"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-s6it7400","versions":[{"created_at":"2026-06-10T14:29:43Z","element_count":72,"note":"5軸GA polish 60->96 by M5 (autonomous)","saved_by":"mcp","sha256":"06ed626aba207404a9561b28437290db45124b6b715875805958ee4134f5c0ee","version":7}]}