{"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-f2z59w9z","versions":[{"created_at":"2026-06-10T18:46:37Z","element_count":73,"note":"5軸GA polish 54->97 by M5 (autonomous)","saved_by":"mcp","sha256":"d784138cba4e13eb7b1b82a37f5a71bfe99493a40b8f1a0ab487f12686d742a4","version":3}]}