{"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-sl0cyrfv","versions":[{"created_at":"2026-06-10T07:42:23Z","element_count":90,"note":"5軸GA polish 61->98 by M5 (autonomous)","saved_by":"mcp","sha256":"52d486834347c9f7e1826ec60b613d075b74a8182680a320098d823500bad38b","version":2}]}