refactor: 消除所有 api-services-raw 残留调用，API 口径完全统一

- dashboardApi 新增 resolveTodo/ignoreTodo/batchResolveTodos/batchIgnoreTodos
- notificationsApi 新增 checkContracts/test
- settingsApi 新增 confirmRetirementPolicy
- socialInsuranceApi 新增 monthlyChanges/housingMonthlyChanges/housingActiveDeclaration
- Dashboard.tsx 替换 4 处 apiPatch
- Settings.tsx 替换 4 处 apiPost
- Notifications.tsx 替换 1 处 apiPost
- SocialInsurance.tsx 替换 4 处 apiGet
- AIAssistant.tsx 移除未使用的 apiPost 导入
- 所有页面零 api-services-raw 依赖

frontend/src/pages/AIAssistant.tsx

@@ -8,7 +8,6 @@ import rehypeRaw from 'rehype-raw'
 import { Document, Packer, Paragraph, HeadingLevel, TextRun, Table, TableRow, TableCell, WidthType, BorderStyle, AlignmentType } from 'docx'
 import { saveAs } from 'file-saver'
 import { aiApi, rosterApi, employeeApi } from '../lib/api-services'
-import { post as apiPost } from '../lib/api-services-raw'
 import { useAuthStore } from '../store/authStore'
 import Card from '../components/ui/Card'
 import Button from '../components/ui/Button'