{"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-xx8bh0y5","versions":[{"created_at":"2026-08-14T09:10:49Z","element_count":122,"note":"loop3: 設計時延床 85.0㎡ を投入 (見積過大の根治)","saved_by":"mcp","sha256":"4a782d18acc42a1289496f6e5f25907c4d73300d88ee0fea9c991360e3be3222","version":2},{"created_at":"2026-08-14T09:10:48Z","element_count":122,"note":"言葉から生成: LDK+主寝室+子供室+浴室+収納","saved_by":"mcp:create","sha256":"","version":1}]}