{"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-03-ju8n5jwf","versions":[{"created_at":"2026-06-10T23:29:28Z","element_count":54,"note":"","saved_by":"mcp","sha256":"c23decaafd9b1008e0444aa13de98b3c0d7ed1348e222933cc6a735860cbfe49","version":4}]}