{"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-lg4vkyc6","versions":[{"created_at":"2026-06-30T11:15:17Z","element_count":254,"note":"言葉から生成: 総2階(箱) / 狭小の町家・吹抜・坪庭","saved_by":"mcp:create","sha256":"","version":1}]}