{"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-0iwbmdqn","versions":[{"created_at":"2026-06-10T17:40:00Z","element_count":72,"note":"5軸GA polish 61->96 by M5 (autonomous)","saved_by":"mcp","sha256":"e3dc8f5367e6454f8f294a596504ff500d931046850d03b090c2e61833adff91","version":3}]}