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/portal/ResignationApply.tsx

@@ -5,19 +5,11 @@ import { useState } from 'react'
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
 import { toast } from 'sonner'
 import { UserX, Clock, Check, X, FileText } from 'lucide-react'
+import { portalApi } from '../../lib/api-services'
 import Card from '../../components/ui/Card'
 import Button from '../../components/ui/Button'
 import { Input, Label, Select } from '../../components/ui/Input'
 import { InlineAlert } from '../../components/ui/InlineAlert'
-import axios from 'axios'
-
-/** 员工端 API 实例 */
-const portalApi = axios.create({ baseURL: '/api/v1/portal' })
-portalApi.interceptors.request.use((config: any) => {
-  const token = localStorage.getItem('portalToken')
-  if (token) config.headers.Authorization = `Bearer ${token}`
-  return config
-})
 
 /** 离职原因选项 */
 const RESIGN_REASONS = [
@@ -51,16 +43,14 @@ export default function ResignationApply() {
   const { data: records = [], isLoading } = useQuery<any[]>({
     queryKey: ['portal-resignation-status'],
     queryFn: async () => {
-      const res = await portalApi.get('/resignation/status') as any
-      return Array.isArray(res?.data) ? res.data : []
+      return await portalApi.resignationStatus()
     },
   })
 
   /** 提交离职申请 */
   const submitMutation = useMutation({
     mutationFn: async (data: { reason: string; expectedDate: string; remark: string }) => {
-      const res = await portalApi.post('/resignation/submit', data) as any
-      return res.data
+      return await portalApi.resignationSubmit(data)
     },
     onSuccess: () => {
       toast.success('离职申请已提交，请等待HR审批')
@@ -75,8 +65,7 @@ export default function ResignationApply() {
   /** 撤回离职申请 */
   const withdrawMutation = useMutation({
     mutationFn: async (id: string) => {
-      const res = await portalApi.post(`/resignation/${id}/withdraw`) as any
-      return res.data
+      return await portalApi.resignationWithdraw(id)
     },
     onSuccess: () => {
       toast.success('离职申请已撤回')