{"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-09-2l53xc8v","versions":[{"created_at":"2026-06-10T23:29:54Z","element_count":50,"note":"","saved_by":"mcp","sha256":"71af80e578d24b69ee3ad8c2bb1f46967185bfbc9c55eb7adc5ec95cc2f27b2d","version":4}]}