fix: display canonical API failure labels in the grading page

frontend/src/App.tsx

@@ -34,6 +34,7 @@ const pageTypeLabel = (value: string) => pageTypeLabels[value] || '未分类页
 const statusLabels: Record<string, string> = { pending: '待评分', scored: '模型已评分', reviewed: '教师已复核', needs_review: '待教师复核', unscorable: '材料缺失或解析失败', failed: '评分失败' };
 const statusLabel = (value: string) => statusLabels[value] || value;
 const scoreStatusLabel = (row: any) => {
+  if (row.status_label) return row.status_label;
   if (row.status !== 'failed') return statusLabel(row.status);
   if (/模型证据|target_id|评分项或满分|JSON校验/.test(row.error || '')) return '模型输出校验失败';
   if (/ConnectError|Timeout|Network|连接|超时|HTTP/i.test(row.error || '')) return '模型连接失败';