{"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-08-rn4hfv3n","versions":[{"created_at":"2026-06-10T23:29:52Z","element_count":54,"note":"","saved_by":"mcp","sha256":"42543bba520d02ca89efc8dd03455268964e012986d0432d0a0cabd80ae6ae1e","version":4}]}