{"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-kd5mve0x","versions":[{"created_at":"2026-06-10T07:42:19Z","element_count":91,"note":"5軸GA polish 59->98 by M5 (autonomous)","saved_by":"mcp","sha256":"11aff074285465393dbdf84e66a5e3216f5a007d385c01ac054a073e3238be53","version":2}]}