增加自动亮色/暗色主题切换 + 清理 pyc 文件

- 新建 store/theme.tsx: 亮色/暗色/跟随系统三种模式
- App.tsx: ThemeProvider + ConfigProvider 暗色算法
- MainLayout: 侧边栏主题切换按钮，Sider/Content 随主题变化
- 所有页面硬编码颜色替换为 antd token
- AssignmentsPage: Tag 用预设颜色名适配暗色，未选中背景用 colorBgContainer
- LoginPage: 暗色深色渐变背景
- 从 git 移除所有 __pycache__/*.pyc 文件

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

web/frontend/src/pages/LoginTasksPage.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useState, useRef, useMemo, useCallback } from 'react';
 import {
-  Table, Button, Select, message, Tag, Space, Spin, InputNumber, Tooltip, Popconfirm,
+  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 { accountApi, loginApi } from '../api/modules';
@@ -39,6 +39,8 @@ export default function LoginTasksPage() {
   const logEndRef = useRef<HTMLDivElement | null>(null);
   const user = getUser();
 
+  const { token } = theme.useToken();
+
   const canBatch = hasPerm(user, 'login:batch');
 
   // 从账号中提取所有标签
@@ -259,7 +261,7 @@ export default function LoginTasksPage() {
   return (
     <div style={{ height: '100%', display: 'flex', flexDirection: 'column', overflow: 'hidden' }}>
       {/* 标题 + 筛选栏 */}
-      <div style={{ flexShrink: 0, paddingBottom: 8, borderBottom: '1px solid #f0f0f0' }}>
+      <div style={{ flexShrink: 0, paddingBottom: 8, borderBottom: `1px solid ${token.colorBorderSecondary}` }}>
         <h2 style={{ marginTop: 0, marginBottom: 6 }}>登录任务</h2>
         {canBatch && (
           <div style={{ display: 'flex', alignItems: 'center', gap: 8, flexWrap: 'wrap' }}>
@@ -314,7 +316,7 @@ export default function LoginTasksPage() {
               }}
               dropdownRender={(menu) => (
                 <>
-                  <div style={{ padding: '4px 8px', borderBottom: '1px solid #f0f0f0', display: 'flex', gap: 8 }}>
+                  <div style={{ padding: '4px 8px', borderBottom: `1px solid ${token.colorBorderSecondary}`, display: 'flex', gap: 8 }}>
                     <Button size="small" type="link" onClick={() => { setSelectedIds(accounts.map((a) => a.id)); setSelectedTags([]); }}>
                       全选 ({accounts.length})
                     </Button>
@@ -327,13 +329,13 @@ export default function LoginTasksPage() {
               )}
             />
             {selectedTags.length > 0 && (
-              <span style={{ color: '#888', fontSize: 12, whiteSpace: 'nowrap' }}>
+              <span style={{ color: token.colorTextSecondary, fontSize: 12, whiteSpace: 'nowrap' }}>
                 标签选中 {accounts.filter((a) => selectedTags.includes((a.tag || '').trim())).length} 个
               </span>
             )}
             <Tooltip title="同时登录的账号数，1为顺序执行">
               <Space size={4}>
-                <ThunderboltOutlined style={{ color: '#888' }} />
+                <ThunderboltOutlined style={{ color: token.colorTextSecondary }} />
                 <InputNumber
                   min={1}
                   max={10}
@@ -366,10 +368,10 @@ export default function LoginTasksPage() {
       {/* 概览 + 任务列表区域 */}
       <div style={{ flex: 1, minHeight: 0, display: 'flex', flexDirection: 'column', paddingTop: 6 }}>
         {/* 概览 */}
-        <div style={{ flexShrink: 0, display: 'flex', alignItems: 'center', gap: 16, fontSize: 13, color: '#666', padding: '4px 0' }}>
+        <div style={{ flexShrink: 0, display: 'flex', alignItems: 'center', gap: 16, fontSize: 13, color: token.colorTextSecondary, padding: '4px 0' }}>
           <span>共 <b>{tasks.length}</b> 个任务</span>
-          <span>成功 <b style={{ color: '#3f8600' }}>{successCount}</b></span>
-          <span>失败 <b style={{ color: '#cf1322' }}>{failedCount}</b></span>
+          <span>成功 <b style={{ color: token.colorSuccess }}>{successCount}</b></span>
+          <span>失败 <b style={{ color: token.colorError }}>{failedCount}</b></span>
           {batchId && <span>批次: <b>{batchId}</b></span>}
           <div style={{ flex: 1 }} />
           {selectedRowKeys.length > 0 && (
@@ -410,14 +412,14 @@ export default function LoginTasksPage() {
       </div>
 
       {/* 实时日志 - 底部可折叠 */}
-      <div style={{ flexShrink: 0, borderTop: '1px solid #f0f0f0', marginTop: 4 }}>
+      <div style={{ flexShrink: 0, borderTop: `1px solid ${token.colorBorderSecondary}`, marginTop: 4 }}>
         <div
           style={{ display: 'flex', alignItems: 'center', cursor: 'pointer', padding: '4px 0', userSelect: 'none' }}
           onClick={() => setLogVisible((v) => !v)}
         >
           <span style={{ fontWeight: 500, fontSize: 13 }}>实时日志</span>
           {logVisible ? <UpOutlined style={{ marginLeft: 6, fontSize: 10 }} /> : <DownOutlined style={{ marginLeft: 6, fontSize: 10 }} />}
-          {logs.length > 0 && <span style={{ marginLeft: 8, fontSize: 12, color: '#999' }}>{logs.length} 条</span>}
+          {logs.length > 0 && <span style={{ marginLeft: 8, fontSize: 12, color: token.colorTextTertiary }}>{logs.length} 条</span>}
           {wsConnected && <Tag color="processing" style={{ marginLeft: 8 }}>连接中</Tag>}
         </div>
         {logVisible && (
@@ -428,7 +430,7 @@ export default function LoginTasksPage() {
               fontFamily: 'monospace',
               fontSize: 12,
               padding: 4,
-              backgroundColor: '#fafafa',
+              backgroundColor: token.colorBgLayout,
               borderRadius: 4,
             }}
           >
@@ -440,10 +442,10 @@ export default function LoginTasksPage() {
                   key={i}
                   style={{
                     color:
-                      log.level === 'error' ? '#ff4d4f' :
-                      log.level === 'success' ? '#52c41a' :
-                      log.level === 'warning' ? '#fa8c16' :
-                      'rgba(0,0,0,0.65)',
+                      log.level === 'error' ? token.colorError :
+                      log.level === 'success' ? token.colorSuccess :
+                      log.level === 'warning' ? token.colorWarning :
+                      token.colorText,
                   }}
                 >
                   {log.message}