{"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-67z339ns","versions":[{"created_at":"2026-06-10T13:15:55Z","element_count":63,"note":"backfill: 延床=居室床スラブ実面積93.9㎡(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":"66df32d7fabff5c2afb07debc52b8dc1a7c2d64908b238528841e8817b71576b","version":10},{"created_at":"2026-06-10T09:37:52Z","element_count":83,"note":"5軸GA polish 44->98 by M5 (autonomous)","saved_by":"mcp","sha256":"5694d777b1b499f7cc2217e4d71ce08e31f6f630d6d034db69ecf6a948cd245e","version":2}]}