{"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-nyxcv1k1","versions":[{"created_at":"2026-06-10T07:25:34Z","element_count":89,"note":"5軸GA polish 61->98 by M5 (autonomous)","saved_by":"mcp","sha256":"3976441a0a30c3b13f62cd01e4d8b0ac2ece1248924327f454a73df3123275d1","version":2}]}