{"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-xls8lg8h","versions":[{"created_at":"2026-06-10T13:27:08Z","element_count":77,"note":"backfill: 延床=居室床スラブ実面積77.0㎡(基礎/屋外/ロフト除外)。設備数量/コスト過大の是正","saved_by":"mcp","sha256":"22afab92bdfc9941edbea7a460314cfa1a1bf6f3ce85556c5848180c19ac37ed","version":9},{"created_at":"2026-06-10T11:26:46Z","element_count":90,"note":"5軸GA polish 56->98 by M5 (autonomous)","saved_by":"mcp","sha256":"31d8b90581918b838417115ae36513e10111c5079dae6eb80cbcf2ef0ed3d986","version":3}]}