fix: 新增后端 /api/v1/salary/dashboard 路由

- 创建 salary.routes.ts，提供薪酬分析数据
- 基于 Payslip 模型计算部门对比、月度趋势、同比环比
- 在 app.ts 中挂载 /api/v1/salary 路由

backend/src/app.ts

@@ -65,6 +65,7 @@ import specialStatusRoutes from './routes/special-status.routes'
 import companyFileRoutes from './routes/company-file.routes'
 import acceptanceTestRoutes from './routes/acceptance-test.routes'
 import leaveRoutes from './routes/leave.routes'
+import salaryRoutes from './routes/salary.routes'
 app.use('/api/v1/auth', authRoutes)
 app.use('/api/v1/dashboard', dashboardRoutes)
 app.use('/api/v1/employees', employeeRoutes)
@@ -93,6 +94,7 @@ app.use('/api/v1/special-statuses', specialStatusRoutes)
 app.use('/api/v1/company-files', companyFileRoutes)
 app.use('/api/v1/acceptance-tests', acceptanceTestRoutes)
 app.use('/api/v1/leaves', leaveRoutes)
+app.use('/api/v1/salary', salaryRoutes)
 
 app.use(errorHandler)
 

backend/src/routes/salary.routes.ts

@@ -0,0 +1,88 @@
+import { Router } from 'express'
+import prisma from '../lib/prisma'
+import { authMiddleware, AuthRequest } from '../middleware/auth'
+
+const router = Router()
+
+router.get('/dashboard', authMiddleware, async (req: AuthRequest, res) => {
+  try {
+    const orgId = req.user!.orgId
+    const year = Number(req.query.year) || new Date().getFullYear()
+    const yearPrefix = `${year}-`
+
+    // 获取该年度所有工资条
+    const payslips = await prisma.payslip.findMany({
+      where: {
+        orgId,
+        month: { startsWith: yearPrefix },
+      },
+      include: {
+        employee: { select: { department: true } },
+      },
+    })
+
+    // 概览
+    const totalEmployees = new Set(payslips.map(p => p.employeeId)).size
+    const allNetPays = payslips.map(p => p.netPay).sort((a, b) => a - b)
+    const avgSalary = payslips.length > 0 ? payslips.reduce((s, p) => s + p.netPay, 0) / payslips.length : 0
+    const medianSalary = allNetPays.length > 0
+      ? allNetPays.length % 2 === 0
+        ? (allNetPays[allNetPays.length / 2 - 1] + allNetPays[allNetPays.length / 2]) / 2
+        : allNetPays[Math.floor(allNetPays.length / 2)]
+      : 0
+    const totalAnnual = payslips.reduce((s, p) => s + p.netPay, 0)
+
+    // 同比：与上一年度对比
+    const prevYearPrefix = `${year - 1}-`
+    const prevPayslips = await prisma.payslip.findMany({
+      where: {
+        orgId,
+        month: { startsWith: prevYearPrefix },
+      },
+    })
+    const prevTotal = prevPayslips.reduce((s, p) => s + p.netPay, 0)
+    const yoy = prevTotal > 0 ? ((totalAnnual - prevTotal) / prevTotal) * 100 : undefined
+
+    // 环比：与上个月对比（12月 vs 11月）
+    const decPayslips = payslips.filter(p => p.month === `${year}-12`)
+    const novPayslips = payslips.filter(p => p.month === `${year}-11`)
+    const decTotal = decPayslips.reduce((s, p) => s + p.netPay, 0)
+    const novTotal = novPayslips.reduce((s, p) => s + p.netPay, 0)
+    const mom = novTotal > 0 ? ((decTotal - novTotal) / novTotal) * 100 : undefined
+
+    // 部门薪酬对比
+    const deptMap = new Map<string, { count: number; total: number }>()
+    for (const p of payslips) {
+      const dept = p.employee?.department || '未分配'
+      const cur = deptMap.get(dept) || { count: 0, total: 0 }
+      cur.count += 1
+      cur.total += p.netPay
+      deptMap.set(dept, cur)
+    }
+    const departments = Array.from(deptMap.entries())
+      .map(([name, v]) => ({ name, count: v.count, avgSalary: v.count > 0 ? v.total / v.count : 0 }))
+      .sort((a, b) => b.avgSalary - a.avgSalary)
+
+    // 月度趋势
+    const monthMap = new Map<string, number>()
+    for (const p of payslips) {
+      monthMap.set(p.month, (monthMap.get(p.month) || 0) + p.netPay)
+    }
+    const monthlyTrend = Array.from(monthMap.entries())
+      .map(([month, total]) => ({ month: month.slice(5), total }))
+      .sort((a, b) => a.month.localeCompare(b.month))
+
+    res.json({
+      success: true,
+      data: {
+        summary: { totalEmployees, avgSalary, medianSalary, totalAnnual, yoy, mom },
+        departments,
+        monthlyTrend,
+      },
+    })
+  } catch (err) {
+    res.status(500).json({ success: false, error: { code: 'INTERNAL_ERROR', message: '获取薪酬分析数据失败' } })
+  }
+})
+
+export default router