{"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-g4v8vbk2","versions":[{"created_at":"2026-06-10T16:23:02Z","element_count":90,"note":"5軸GA polish 54->98 by M5 (autonomous)","saved_by":"mcp","sha256":"51add41bd093d0e9f25f3e221f19615666c457e9550362f6fbe05033028df367","version":2}]}