登录任务增加代理切换次数设置

- 后端: LoginBatchRequest 增加 max_proxy_retries 字段，默认10，0=无限
- 核心: DouyuLogin 极验验证循环根据 max_proxy_retries 控制重试
- 前端: 筛选栏增加代理切换次数输入框，Tooltip 提示0=无限切换直到成功

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

web/frontend/src/pages/LoginTasksPage.tsx

@@ -2,7 +2,7 @@ import { useEffect, useState, useRef, useMemo, useCallback } from 'react';
 import {
   Table, Button, Select, message, Tag, Space, Spin, InputNumber, Tooltip, Popconfirm, theme,
 } from 'antd';
-import { PlayCircleOutlined, StopOutlined, FilterOutlined, ThunderboltOutlined, ReloadOutlined, DownOutlined, UpOutlined, DeleteOutlined } from '@ant-design/icons';
+import { PlayCircleOutlined, StopOutlined, FilterOutlined, ThunderboltOutlined, ReloadOutlined, DownOutlined, UpOutlined, DeleteOutlined, SwapOutlined } from '@ant-design/icons';
 import { accountApi, loginApi } from '../api/modules';
 import { getUser, hasPerm } from '../store/auth';
 import { formatTime } from '../utils/time';
@@ -33,6 +33,7 @@ export default function LoginTasksPage() {
   const [wsConnected, setWsConnected] = useState(false);
   const [selectedTags, setSelectedTags] = useState<string[]>([]);
   const [concurrency, setConcurrency] = useState(3);
+  const [maxProxyRetries, setMaxProxyRetries] = useState(10);
   const [logVisible, setLogVisible] = useState(true);
   const [selectedRowKeys, setSelectedRowKeys] = useState<number[]>([]);
   const wsRef = useRef<WebSocket | null>(null);
@@ -134,7 +135,7 @@ export default function LoginTasksPage() {
     setLoading(true);
     setLogs([]);
     try {
-      const result = await loginApi.createBatch(accountIds, 5, concurrency);
+      const result = await loginApi.createBatch(accountIds, 5, concurrency, maxProxyRetries);
       setBatchId(result.batch_id);
       message.success(`已创建登录任务，共 ${result.count} 个账号`);
 
@@ -346,6 +347,19 @@ export default function LoginTasksPage() {
                 />
               </Space>
             </Tooltip>
+            <Tooltip title="代理切换次数，0=无限切换直到成功">
+              <Space size={4}>
+                <SwapOutlined style={{ color: token.colorTextSecondary }} />
+                <InputNumber
+                  min={0}
+                  max={999}
+                  value={maxProxyRetries}
+                  onChange={(v) => setMaxProxyRetries(v ?? 10)}
+                  style={{ width: 55 }}
+                  size="small"
+                />
+              </Space>
+            </Tooltip>
             <Button
               type="primary"
               icon={<PlayCircleOutlined />}