{"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-bgvfe4o8","versions":[{"created_at":"2026-10-23T12:04:41Z","element_count":20,"note":"言葉から生成: 小規模平屋住宅 74.43㎡","saved_by":"mcp:create","sha256":"","version":1}]}