{"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-radstockwillowbungal-vz9dweaq","versions":[{"created_at":"2026-06-10T13:19:58Z","element_count":63,"note":"backfill: 延床=居室床スラブ実面積106.2㎡(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":"b1e535cc45c007308cbc9bea702336fc1649b0567b8cb284acbc4db93176a3c8","version":10},{"created_at":"2026-06-10T10:23:19Z","element_count":90,"note":"5軸GA polish 43->98 by M5 (autonomous)","saved_by":"mcp","sha256":"a8e9cde22bcb171cb6804e0522f0215d41ba654431fb394e7c3718f3504007c8","version":2}]}