{"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-btcd7fu5","versions":[{"created_at":"2026-06-10T07:59:18Z","element_count":89,"note":"5軸GA polish 54->98 by M5 (autonomous)","saved_by":"mcp","sha256":"792cec306a7ce30a216d191f441b86931c4403bdcc23313abad14d7e1fb0aed6","version":2}]}