feat: 20260809 系统优化 - 全部28项问题修复(P0×6+P1×16+P2×6)

P0: 福利批量参保/离职证明下载防乱码/考勤模板合并Sheet/补卡修改/附件在线查看删除
P1: 分页pageSize修复/离职导出筛选/撤回删除草稿/加班费自动计算/考勤加班汇总/证据链异常详情/制度催办/模板导入Word/社保封顶保底/校验字段提示/职务字段/社保费用明细/弹窗防误关/身份证查重/证明员工下拉/培训批量
P2: 离职流程去重/社保基数覆盖输入/薪税入口改名/添加员工引导/绩效模板清理

backend/src/routes/employee.routes.ts

@@ -3,6 +3,7 @@ import { authMiddleware, AuthRequest } from '../middleware/auth'
 import { auditLog } from '../middleware/auditLog'
 import { createEvidence } from '../services/evidence.service'
 import prisma from '../lib/prisma'
+import { sha256 } from '../lib/crypto'
 import {
   createEmployeeSchema,
   updateEmployeeSchema,
@@ -97,6 +98,24 @@ router.get('/:id', authMiddleware, async (req: AuthRequest, res, next) => {
   }
 })
 
+// 身份证查重
+router.get('/check-id-card', authMiddleware, async (req: AuthRequest, res, next) => {
+  try {
+    const idCard = req.query.idCard as string
+    if (!idCard || idCard.length < 18) {
+      return res.json({ success: true, data: { exists: false } })
+    }
+    const hash = sha256(idCard)
+    const employee = await prisma.employee.findFirst({
+      where: { orgId: req.user!.orgId, idCardHash: hash },
+      select: { id: true, name: true, department: true, status: true },
+    })
+    res.json({ success: true, data: { exists: !!employee, employee } })
+  } catch (err) {
+    next(err)
+  }
+})
+
 router.post('/', authMiddleware, async (req: AuthRequest, res, next) => {
   try {
     const data = createEmployeeSchema.parse(req.body)