{"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-501-1-amc3w4xx","versions":[{"created_at":"2026-10-27T06:35:25Z","element_count":3089,"note":"","saved_by":"editor","sha256":"8f24ee156e93620b4d481eeb2bcc98b23872000eb1213d7c0ef15cb49375137e","version":3},{"created_at":"2026-10-27T06:16:39Z","element_count":0,"note":"","saved_by":"editor","sha256":"72ab9c0b6afcfecac1e75436b3bdf24f68f6b904447acbfde239954a6dd7e8eb","version":2}]}