{"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-ardennesretreathouse-dofgxga4","versions":[{"created_at":"2026-06-10T17:08:46Z","element_count":73,"note":"5軸GA polish 43->97 by M5 (autonomous)","saved_by":"mcp","sha256":"9a6633976c4ea2f2cdadd6c0a44ed8be40fff6d86113b2954f5f765b8be55018","version":2}]}