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/pages/AuditLog.tsx

@@ -1,7 +1,7 @@
 import { useState } from 'react'
 import { useQuery } from '@tanstack/react-query'
 import { ScrollText, Search, Filter } from 'lucide-react'
-import api from '../lib/api'
+import { auditApi } from '../lib/api-services'
 import Card from '../components/ui/Card'
 import Button from '../components/ui/Button'
 import EmptyState from '../components/ui/EmptyState'
@@ -128,21 +128,19 @@ export default function AuditLog() {
   const { data, isLoading } = useQuery<any>({
     queryKey: ['audit-logs', page, pageSize, action, entity, dateFrom, dateTo],
     queryFn: async () => {
-      const params = new URLSearchParams({ page: String(page), pageSize: String(pageSize) })
-      if (action) params.set('action', action)
-      if (entity) params.set('entity', entity)
-      if (dateFrom) params.set('dateFrom', dateFrom)
-      if (dateTo) params.set('dateTo', dateTo)
-      const res = await api.get(`/audit?${params}`) as any
-      return res.data
+      const p: any = { page, pageSize }
+      if (action) p.action = action
+      if (entity) p.entity = entity
+      if (dateFrom) p.dateFrom = dateFrom
+      if (dateTo) p.dateTo = dateTo
+      return await auditApi.list(p)
     },
   })
 
   const { data: stats } = useQuery<any>({
     queryKey: ['audit-stats'],
     queryFn: async () => {
-      const res = await api.get('/audit/stats') as any
-      return res.data
+      return await auditApi.stats()
     },
   })