{"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-h9pi43nc","versions":[{"created_at":"2026-06-10T18:29:57Z","element_count":89,"note":"5軸GA polish 52->97 by M5 (autonomous)","saved_by":"mcp","sha256":"824531e9c06f4d6a31bd9a53d7e1532e6a103859a3d417e432583f1a49951450","version":3}]}