{"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-06-ty4tp23r","versions":[{"created_at":"2026-06-10T23:29:42Z","element_count":54,"note":"","saved_by":"mcp","sha256":"4034e02afd36d591feae4d71bab565d40568b45a910f1a853e6e26f3fee81171","version":4}]}