feat: AIHR 智能人力资源管理系统初始提交

- 员工花名册管理（加密存储、导入导出）
- 薪酬管理（发薪批次、薪酬模版、加班费计算、工资条）
- 社保公积金（多城市配置、版本管理、基数调整）
- 解聘管理（6步流程、证据链、工作交接）
- AI 助手（合同审查、风险预测、RAG 知识库）
- Dashboard 仪表盘
- 设置与通知

backend/src/app.ts

@@ -0,0 +1,68 @@
+import express from 'express'
+import cors from 'cors'
+import helmet from 'helmet'
+import morgan from 'morgan'
+import compression from 'compression'
+import { errorHandler } from './middleware/errorHandler'
+import { apiLimiter } from './middleware/rateLimit'
+
+const app = express()
+
+app.use(helmet())
+app.use(compression())
+app.use(
+  cors({
+    origin: process.env.CORS_ORIGIN || 'http://localhost:5173',
+    credentials: true,
+  }),
+)
+app.use(express.json())
+app.use(morgan('dev'))
+
+app.get('/health', (_req, res) => {
+  res.json({ success: true, data: { status: 'ok', timestamp: new Date().toISOString() } })
+})
+
+app.use('/api/v1', apiLimiter)
+
+// 路由挂载
+import authRoutes from './routes/auth.routes'
+import dashboardRoutes from './routes/dashboard.routes'
+import employeeRoutes from './routes/employee.routes'
+import terminationRoutes from './routes/termination.routes'
+import aiRoutes from './routes/ai.routes'
+import portalRoutes from './routes/portal.routes'
+import settingsRoutes from './routes/settings.routes'
+import payrollRoutes from './routes/payroll.routes'
+import payroll2Routes from './routes/payroll2.routes'
+import socialRoutes from './routes/social.routes'
+import notificationRoutes from './routes/notification.routes'
+import attachmentRoutes from './routes/attachment.routes'
+import rosterRoutes from './routes/roster.routes'
+import exportRoutes from './routes/export.routes'
+import importRoutes from './routes/import.routes'
+app.use('/api/v1/auth', authRoutes)
+app.use('/api/v1/dashboard', dashboardRoutes)
+app.use('/api/v1/employees', employeeRoutes)
+app.use('/api/v1/termination', terminationRoutes)
+app.use('/api/v1/ai', aiRoutes)
+app.use('/api/v1/portal', portalRoutes)
+app.use('/api/v1/settings', settingsRoutes)
+app.use('/api/v1/payroll', payrollRoutes)
+app.use('/api/v1/payroll2', payroll2Routes)
+app.use('/api/v1/social', socialRoutes)
+app.use('/api/v1/notifications', notificationRoutes)
+app.use('/api/v1/attachments', attachmentRoutes)
+app.use('/api/v1/roster', rosterRoutes)
+app.use('/api/v1/export', exportRoutes)
+app.use('/api/v1/import', importRoutes)
+
+app.use(errorHandler)
+
+// RAG 知识库自动初始化（异步，不阻塞启动）
+import { seedKnowledgeBase } from './services/rag.service'
+seedKnowledgeBase().catch((err) => {
+  console.warn('[RAG] 知识库初始化失败，AI 问答将不使用 RAG 检索:', err?.message || err)
+})
+
+export default app