{"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-mh4xrff4","versions":[{"created_at":"2026-06-10T16:39:19Z","element_count":84,"note":"5軸GA polish 58->98 by M5 (autonomous)","saved_by":"mcp","sha256":"787abfd32997266ea7e5533c93cccaaf622c26299a18ac8855b61578c11dd8a6","version":2}]}