{"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-04-rbvzbouc","versions":[{"created_at":"2026-06-10T23:29:32Z","element_count":46,"note":"","saved_by":"mcp","sha256":"869efcbe6ec094c90e1de6842d39d2b2194af7aafa89fd73cabacf45a18cf891","version":4}]}