{"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-ot38gnj1","versions":[{"created_at":"2026-06-10T19:02:33Z","element_count":72,"note":"5軸GA polish 61->96 by M5 (autonomous)","saved_by":"mcp","sha256":"b8f396a016bf79932acefdebdb30f21ed447e0d83e31db5f49063e5a50c1888a","version":3}]}