{"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-vv2rhg2p","versions":[{"created_at":"2026-06-10T18:14:03Z","element_count":72,"note":"5軸GA polish 59->97 by M5 (autonomous)","saved_by":"mcp","sha256":"8b71bd181fa365861adf54f18b166ab933a87154641fa50a8aad4ad68b32a772","version":3}]}