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/Calendar.tsx

@@ -3,7 +3,7 @@ import { toast } from 'sonner'
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
 import { Link } from 'react-router-dom'
 import { CalendarDays, Plus, Trash2, ChevronLeft, ChevronRight, X, MapPin, User } from 'lucide-react'
-import api from '../lib/api'
+import { dashboardApi, calendarApi } from '../lib/api-services'
 import Card from '../components/ui/Card'
 import Button from '../components/ui/Button'
 import { Input, Label } from '../components/ui/Input'
@@ -66,22 +66,16 @@ export default function Calendar() {
 
   const { data: calendarData } = useQuery<any>({
     queryKey: ['calendar', calendarMonth],
-    queryFn: async () => {
-      const res = await api.get(`/dashboard/calendar?month=${calendarMonth}`) as any
-      return res.data
-    },
+    queryFn: () => dashboardApi.calendar(calendarMonth),
   })
 
   const { data: customEvents } = useQuery<any[]>({
     queryKey: ['custom-events', calendarMonth],
-    queryFn: async () => {
-      const res = await api.get(`/calendar?month=${calendarMonth}`) as any
-      return res.data
-    },
+    queryFn: () => calendarApi.events(calendarMonth),
   })
 
   const createEventMutation = useMutation({
-    mutationFn: (data: any) => api.post('/calendar', data),
+    mutationFn: (data: any) => calendarApi.createEvent(data),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ['custom-events'] })
       queryClient.invalidateQueries({ queryKey: ['calendar'] })
@@ -93,7 +87,7 @@ export default function Calendar() {
   })
 
   const deleteEventMutation = useMutation({
-    mutationFn: (id: string) => api.delete(`/calendar/${id}`),
+    mutationFn: (id: string) => calendarApi.removeEvent(id),
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: ['custom-events'] })
       queryClient.invalidateQueries({ queryKey: ['calendar'] })