{"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-blackthornhouse-h1dkh8za","versions":[{"created_at":"2026-06-10T13:22:33Z","element_count":85,"note":"backfill: 延床=居室床スラブ実面積81.7㎡(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":"27d5c39f29d8a21c254858222794a6bfde74b5537f842d04d6d555940fe60695","version":10},{"created_at":"2026-06-10T10:22:57Z","element_count":72,"note":"5軸GA polish 43->97 by M5 (autonomous)","saved_by":"mcp","sha256":"312baf726e7c48cac8aa6384c1224b716aac1fe6098304c1b55591db15236819","version":2}]}