{"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-totterdownhouse-q4m5rb5j","versions":[{"created_at":"2026-06-10T13:11:24Z","element_count":66,"note":"backfill: 延床=居室床スラブ実面積90.0㎡(基礎/屋外/ロフト除外)。設備数量/コスト過大の是正","saved_by":"mcp","sha256":"58955871b883d8d06349d2af6c14fc11c8de32ca012810652cf02ed1cea21fca","version":11},{"created_at":"2026-06-10T08:22:34Z","element_count":73,"note":"5軸GA polish 43->97 by M5 (autonomous)","saved_by":"mcp","sha256":"ba511503ce4758fb0686d9ec51ec9447b75382b6441c233f11b5c978ed438431","version":2}]}