{"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-10-v46q9b88","versions":[{"created_at":"2026-06-10T23:29:56Z","element_count":50,"note":"","saved_by":"mcp","sha256":"97b313be1cae05acb886e16aca6996bf41b6747401041995d7c4933b13290418","version":4}]}