修复错题图片显示、Tab 刷新跳转，奥数仅数学并支持删除。

- 图片通过带 Token 的 blob 请求加载，修复不显示

- URL ?tab= 保持当前标签，刷新列表不再重置到成绩录入

- 奥数区固定数学科目；错题卡片与详情增加删除

frontend/src/pages/WrongQuestionDetail.tsx

@@ -1,6 +1,7 @@
-import { Alert, Button, Col, Input, Modal, Row, Space, Spin, Typography, message } from 'antd'
+import { Alert, Button, Col, Input, Modal, Popconfirm, Row, Space, Spin, Typography, message } from 'antd'
 import { useEffect, useState } from 'react'
 import ReactMarkdown from 'react-markdown'
+import AuthenticatedImage from '../components/AuthenticatedImage'
 import { wrongQuestionApi } from '../api/client'
 import type { WrongQuestion } from '../types'
 import { STATUS_LABELS } from '../types'
@@ -10,15 +11,23 @@ interface Props {
   open: boolean
   onClose: () => void
   onUpdated: () => void
+  onDeleted?: () => void
 }
 
-export default function WrongQuestionDetail({ questionId, open, onClose, onUpdated }: Props) {
+export default function WrongQuestionDetail({
+  questionId,
+  open,
+  onClose,
+  onUpdated,
+  onDeleted,
+}: Props) {
   const [wq, setWq] = useState<WrongQuestion | null>(null)
   const [loading, setLoading] = useState(false)
   const [questionText, setQuestionText] = useState('')
   const [solutionText, setSolutionText] = useState('')
   const [saving, setSaving] = useState(false)
   const [regenerating, setRegenerating] = useState(false)
+  const [deleting, setDeleting] = useState(false)
 
   const load = async () => {
     setLoading(true)
@@ -73,6 +82,20 @@ export default function WrongQuestionDetail({ questionId, open, onClose, onUpdat
     onClose()
   }
 
+  const handleDelete = async () => {
+    setDeleting(true)
+    try {
+      await wrongQuestionApi.remove(questionId)
+      message.success('已删除')
+      onDeleted?.()
+      onClose()
+    } catch {
+      message.error('删除失败')
+    } finally {
+      setDeleting(false)
+    }
+  }
+
   return (
     <Modal
       title={
@@ -86,6 +109,11 @@ export default function WrongQuestionDetail({ questionId, open, onClose, onUpdat
       style={{ maxWidth: 960 }}
       footer={
         <Space wrap>
+          <Popconfirm title="确定删除该题？" onConfirm={handleDelete}>
+            <Button danger loading={deleting}>
+              删除
+            </Button>
+          </Popconfirm>
           <Button onClick={handleRetryOcr}>重新 OCR</Button>
           <Button loading={regenerating} onClick={handleRegenerate}>
             重新生成解法
@@ -110,8 +138,8 @@ export default function WrongQuestionDetail({ questionId, open, onClose, onUpdat
             )}
             <Row gutter={16} style={{ marginTop: 12 }}>
               <Col xs={24} md={10}>
-                <img
-                  src={wrongQuestionApi.imageUrl(wq.id)}
+                <AuthenticatedImage
+                  questionId={wq.id}
                   alt="原题"
                   style={{ width: '100%', borderRadius: 8, border: '1px solid #f0f0f0' }}
                 />