{"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-4prc7fec","versions":[{"created_at":"2026-06-10T16:39:00Z","element_count":89,"note":"5軸GA polish 56->98 by M5 (autonomous)","saved_by":"mcp","sha256":"0f5c631d4d59e9a595c6448086193326251c9f255ebc604fdbf4d9444c5da285","version":2}]}