feat: 实现多端飞书登录功能

1. 飞书客户端内：静默自动登录
   - 检测飞书环境 (userAgent + ttjsBridge)
   - 调用 ttjsBridge.getAuthCode() 获取授权码
   - 自动登录到后台

2. 飞书客户端外：扫码登录
   - 后端新增三个接口：
     * POST /api/v1/auth/qrcode-login - 生成登录会话和二维码
     * GET /api/v1/auth/qrcode-login/status - 轮询登录状态
     * GET /login/qrcode/{id} - 飞书授权回调
   - 前端新增 QRCodeLogin 组件：
     * 使用 qrcode.react 生成二维码
     * 每 2 秒轮询登录状态
     * 状态：loading → pending → scanning → success/expired

3. 数据库表：feishu_login_session
   - 存储 session_id, auth_url, status, user_id
   - 状态：pending, scanning, success, expired
   - 2 分钟过期机制

4. 其他优化
   - 移除审批详情页的 header
   - 更新 PROJECT_ISSUES.md 文档

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/pages/login/QRCodeLogin.tsx

@@ -0,0 +1,187 @@
+import { useState, useEffect, useRef } from 'react'
+import { Dialog } from 'antd-mobile'
+import { QRCodeSVG } from 'qrcode.react'
+import { useNavigate } from 'react-router-dom'
+import Toast from 'antd-mobile'
+import styles from './QRCodeLogin.module.css'
+
+interface QRCodeLoginProps {
+  visible: boolean
+  onClose: () => void
+}
+
+export default function QRCodeLogin({ visible, onClose }: QRCodeLoginProps) {
+  const navigate = useNavigate()
+  const [qrcodeUrl, setQrcodeUrl] = useState('')
+  const [sessionId, setSessionId] = useState('')
+  const [status, setStatus] = useState<'loading' | 'pending' | 'scanning' | 'success' | 'expired'>('loading')
+  const pollTimerRef = useRef<NodeJS.Timeout | null>(null)
+
+  useEffect(() => {
+    if (visible) {
+      initQrcodeLogin()
+    }
+
+    return () => {
+      if (pollTimerRef.current) {
+        clearTimeout(pollTimerRef.current)
+      }
+    }
+  }, [visible])
+
+  const initQrcodeLogin = async () => {
+    setStatus('loading')
+    try {
+      // 生成登录二维码
+      const response = await fetch('/api/v1/auth/qrcode-login', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          tenant_key: '14e7bc0fe5985740',
+        }),
+      })
+
+      const result = await response.json()
+
+      if (result.code === 0) {
+        setQrcodeUrl(result.data.auth_url)
+        setSessionId(result.data.session_id)
+        setStatus('pending')
+        // 开始轮询登录状态
+        startPolling(result.data.session_id)
+      } else {
+        Toast.show(result.message || '生成二维码失败')
+        setStatus('expired')
+      }
+    } catch (error) {
+      console.error('生成二维码失败:', error)
+      Toast.show('生成二维码失败')
+      setStatus('expired')
+    }
+  }
+
+  const startPolling = (id: string) => {
+    const poll = async () => {
+      try {
+        const response = await fetch(`/api/v1/auth/qrcode-login/status?session_id=${id}`)
+        const result = await response.json()
+
+        if (result.code === 0) {
+          if (result.data.status === 'success') {
+            setStatus('success')
+            // 登录成功，保存 token
+            const { token, user } = result.data
+            localStorage.setItem('token', token)
+            localStorage.setItem('i18nextLng', 'zh')
+            // 触发登录成功事件，让 store 更新
+            window.dispatchEvent(new CustomEvent('feishu-login-success', { detail: { user, token }))
+
+            Toast.show('登录成功')
+            setTimeout(() => {
+              onClose()
+              navigate('/dashboard')
+            }, 500)
+          } else if (result.data.status === 'expired') {
+            setStatus('expired')
+            Toast.show('二维码已过期，请刷新重试')
+          } else if (result.data.status === 'scanning') {
+            setStatus('scanning')
+            // 继续轮询
+            pollTimerRef.current = setTimeout(poll, 2000)
+          } else {
+            // pending，继续轮询
+            pollTimerRef.current = setTimeout(poll, 2000)
+          }
+        } else if (result.message?.includes('过期')) {
+          setStatus('expired')
+        } else {
+          // 继续轮询
+          pollTimerRef.current = setTimeout(poll, 2000)
+        }
+      } catch (error) {
+        console.error('轮询登录状态失败:', error)
+        // 继续轮询
+        pollTimerRef.current = setTimeout(poll, 2000)
+      }
+    }
+
+    pollTimerRef.current = setTimeout(poll, 2000)
+  }
+
+  const getStatusText = () => {
+    switch (status) {
+      case 'loading':
+        return '正在生成二维码...'
+      case 'pending':
+        return '请使用飞书扫码登录'
+      case 'scanning':
+        return '已扫码，请在手机上确认'
+      case 'success':
+        return '登录成功！'
+      case 'expired':
+        return '二维码已过期'
+      default:
+        return ''
+    }
+  }
+
+  const getStatusColor = () => {
+    switch (status) {
+      case 'pending':
+        return '#1677ff'
+      case 'scanning':
+        return '#faad14'
+      case 'success':
+        return '#52c41a'
+      case 'expired':
+        return '#ff4d4f'
+      default:
+        return '#999'
+    }
+  }
+
+  const handleRefresh = () => {
+    if (pollTimerRef.current) {
+      clearTimeout(pollTimerRef.current)
+    }
+    initQrcodeLogin()
+  }
+
+  return (
+    <Dialog
+      visible={visible}
+      content={
+        <div className={styles.qrcodeContainer}>
+          {status === 'loading' && <div className={styles.loading}>正在生成二维码...</div>}
+
+          {qrcodeUrl && status !== 'loading' && (
+            <>
+              <div className={styles.qrcode}>
+                <QRCodeSVG
+                  value={qrcodeUrl}
+                  size={200}
+                  level="M"
+                  includeMargin={false}
+                />
+              </div>
+
+              <div className={styles.status} style={{ color: getStatusColor() }}>
+                {getStatusText()}
+              </div>
+
+              {(status === 'expired') && (
+                <div className={styles.actions}>
+                  <button className={styles.refreshBtn} onClick={handleRefresh}>
+                    刷新二维码
+                  </button>
+                </div>
+              )}
+            </>
+          )}
+        </div>
+      }
+      onClose={onClose}
+      closeOnMaskClick={status !== 'scanning' && status !== 'success'}
+    />
+  )
+}