优化: 大文件拆分+代码分割+按需加载+console清理+any类型替换

- Money.tsx (2260行→54行): 拆分为 money/ 子目录4个组件, React.lazy二级分割
- AIAssistant.tsx (2038行→63行): 拆分为 ai-assistant/ 子目录6个组件, React.lazy二级分割
- xlsx改为动态导入, OvertimeTab从345KB降至12.7KB
- api-services.ts: 请求参数 any→Record<string,unknown>
- 移除前端3处console.log残留
- 后端console替换为pino logger
- 前后端未使用import/变量清理
- Zod schema验证: termination/platform/special-status/work-process
- 新增 leave.routes.ts, acceptance-test.routes.ts
- UI组件: PageGuide, QueryError, Stepper

frontend/src/components/HelpModal.tsx

@@ -1,7 +1,7 @@
 import { useState, useEffect, useRef } from 'react'
 import { HelpCircle, Search, ChevronDown, ChevronRight, Sparkles,
-  Home, Users, FileText, Calculator, Shield, UserX, Bot, 
-  Bell, Settings, Lightbulb, AlertTriangle, CheckCircle, Phone } from 'lucide-react'
+  Home, Users, FileText, Calculator, Bot,
+  Settings, Lightbulb, AlertTriangle, CheckCircle, Phone } from 'lucide-react'
 import Modal from './ui/Modal'
 import { aiApi } from '../lib/api-services'
 import clsx from 'clsx'