fix: 优化文档16项问题修复

- 问题1/3: 绩效考核/培训记录员工姓名可点击跳转员工详情页
- 问题2: 离职证明模板支持自定义+员工端下载
- 问题4(P0): 修复工资填写后数据归零问题
- 问题5: 社保添加员工参保信息列表
- 问题6(P0): 商业保险支持为员工参保
- 问题7(P0): 员工福利支持为员工添加福利
- 问题8: 规章制度支持导入Word文档
- 问题9: 文本模板下载Word增加HTML格式
- 问题10: 模板下载变量替换修复(排除token参数)
- 问题11(P0): 电子签署发起时员工下拉框有选项
- 问题12: 新增绩效记录添加考评人选项
- 问题13: 违纪记录添加处罚执行细节
- 问题14: 特殊员工列表添加查看详情按钮和姓名链接
- 问题15: 员工福利汇总正确显示参保人员
- 问题16(P0): 证据链验证修复(递归排序key+自动修复历史哈希)

frontend/src/pages/SocialInsurance.tsx

@@ -11,6 +11,7 @@ import Button from '../components/ui/Button'
 import { Input, Label } from '../components/ui/Input'
 import { MonthlyRow, MonthlyHousingRow } from './social-insurance/MonthlyRows'
 import SpecialDeductionTab from './social-insurance/SpecialDeductionTab'
+import EmployeeEnrollmentTab from './social-insurance/EmployeeEnrollmentTab'
 
 // 金额格式化：保留两位小数 + 千分位
 const fmt = (n: number) => (n || 0).toLocaleString('zh-CN', { minimumFractionDigits: 2, maximumFractionDigits: 2 })
@@ -18,7 +19,7 @@ const fmt = (n: number) => (n || 0).toLocaleString('zh-CN', { minimumFractionDig
 export default function SocialInsurance() {
   const queryClient = useQueryClient()
   const confirm = useConfirm()
-  const [tab, setTab] = useState<'monthly' | 'social' | 'housing' | 'deduction'>('monthly')
+  const [tab, setTab] = useState<'monthly' | 'social' | 'housing' | 'deduction' | 'enrollment'>('monthly')
   const [city, setCity] = useState<string>('北京')
   const [showAddCity, setShowAddCity] = useState(false)
   const [newCityName, setNewCityName] = useState('')
@@ -374,7 +375,7 @@ export default function SocialInsurance() {
 
       {/* Tab 切换 + 城市选择 */}
       <div className="flex items-center gap-4 border-b">
-        {(['monthly', 'social', 'housing', 'deduction'] as const).map((t) => (
+        {(['monthly', 'social', 'housing', 'enrollment', 'deduction'] as const).map((t) => (
           <button
             key={t}
             className={`px-4 py-2 text-sm font-medium border-b-2 transition-colors ${
@@ -382,7 +383,7 @@ export default function SocialInsurance() {
             }`}
             onClick={() => { setTab(t); setShowVersions(false); setShowNewVersion(false); setShowAdjust(false); setAdjustData(null); setEditItems({}); setEditingId(null); setMonthlyProcessed(false); setProcessStatus(null) }}
           >
-            {t === 'monthly' ? '月度办理' : t === 'social' ? '社保' : t === 'housing' ? '公积金' : '专项附加扣除'}
+            {t === 'monthly' ? '月度办理' : t === 'social' ? '社保' : t === 'housing' ? '公积金' : t === 'enrollment' ? '员工参保' : '专项附加扣除'}
           </button>
         ))}
         {(tab === 'social' || tab === 'housing') && (
@@ -1150,6 +1151,11 @@ export default function SocialInsurance() {
         </div>
       )}
 
+      {/* ========== 员工参保信息 Tab ========== */}
+      {tab === 'enrollment' && (
+        <EmployeeEnrollmentTab />
+      )}
+
       {/* ========== 专项附加扣除 Tab ========== */}
       {tab === 'deduction' && (
         <SpecialDeductionTab month={deductionMonth} setMonth={setDeductionMonth} />