refactor: 全量迁移前端 API 调用到统一 api-services 服务层

- 新建 api-services-raw.ts 导出原始 axios 方法供特殊端点使用
- 完成 api-services.ts 全领域覆盖（auth/employee/roster/dashboard/attendance/payroll/socialInsurance/commercialInsurance/termination/policies/evidence/audit/calendar/companyFiles/notifications/settings/ai/platform/portal/survey/search）
- 迁移所有 47+ 页面文件：pages/、pages/roster/、pages/portal/、pages/platform/、pages/auth/、pages/dashboard/、pages/compliance/
- 移除所有直接 import api from '../../lib/api' 引用
- 修复 Termination.tsx / WorkProcess.tsx 中 string|null 类型错误
- 修复 SocialInsurance.tsx 中 api-services-raw delete 导入名
- 修复 PlatformLogin.tsx 变量遮蔽问题
- tsc --noEmit 零错误，vite build 成功

frontend/src/components/layout/TopNav.tsx

@@ -3,7 +3,7 @@ import { ChevronDown, Settings as SettingsIcon, Bell, Menu, HelpCircle, Smartpho
 import { useState } from 'react'
 import { useQuery } from '@tanstack/react-query'
 import { useAuthStore } from '../../store/authStore'
-import api from '../../lib/api'
+import { dashboardApi } from '../../lib/api-services'
 import Breadcrumb from './Breadcrumb'
 import HelpModal from '../HelpModal'
 import PortalQRModal from '../PortalQRModal'
@@ -19,10 +19,7 @@ export default function TopNav({ onMenuClick }: { onMenuClick?: () => void }) {
 
   const { data: dashboardData } = useQuery<any>({
     queryKey: ['dashboard'],
-    queryFn: async () => {
-      const res = await api.get('/dashboard') as any
-      return res.data
-    },
+    queryFn: () => dashboardApi.data(),
     refetchInterval: 60000,
   })
   const riskCount = dashboardData?.riskSummary?.pending || 0