{"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-21xyz8tz","versions":[{"created_at":"2026-06-10T07:25:54Z","element_count":90,"note":"5軸GA polish 60->98 by M5 (autonomous)","saved_by":"mcp","sha256":"ac3cde25579e51ba6e63392c702085f8b1b2d6401640a04c8c2cbb7732ed7201","version":2}]}