fix: 员工端姓名显示处加上身份证号

后端：
- portal.routes.ts: 密码登录/验证码登录/自动登录返回 idCardNumber
- portal.routes.ts: home/overview 返回 employeeIdCardNumber
- portal.routes.ts: 合同确认接口返回 employeeIdCardNumber

前端：
- EmployeeHome.tsx: 首页欢迎卡片显示身份证号
- PortalLayout.tsx: 顶栏姓名后显示身份证号
- Payslip.tsx: 下载文件名加上身份证号
- ContractConfirm.tsx: 合同确认页显示身份证号

frontend/src/components/layout/PortalLayout.tsx

@@ -38,7 +38,7 @@ export default function PortalLayout({ children }: { children: React.ReactNode }
           </div>
           <div className="flex items-center gap-2 flex-shrink-0">
             {employee.name && (
-              <span className="text-xs text-gray-500 truncate max-w-[60px]">{employee.name}</span>
+              <span className="text-xs text-gray-500 truncate max-w-[120px]">{employee.name}{employee.idCardNumber ? `（${employee.idCardNumber}）` : ''}</span>
             )}
             <button
               onClick={handleLogout}

frontend/src/pages/portal/ContractConfirm.tsx

@@ -94,7 +94,7 @@ export default function ContractConfirm() {
           <Card>
             <div className="space-y-3">
               <div className="text-sm text-gray-600">
-                {data.orgName} 与 {data.employeeName} 的劳动合同
+                {data.orgName} 与 {data.employeeName}{data.employeeIdCardNumber ? `（${data.employeeIdCardNumber}）` : ''} 的劳动合同
               </div>
 
               {data.contract && (

frontend/src/pages/portal/EmployeeHome.tsx

@@ -62,6 +62,7 @@ export default function EmployeeHome() {
           <div>
             <h1 className="text-lg font-bold">你好，{employee.name || '同事'}</h1>
             <p className="text-sm text-indigo-100 mt-1">{employee.department || ''} · {employee.position || ''}</p>
+            {employee.idCardNumber && <p className="text-xs text-indigo-200 mt-0.5 font-mono">{employee.idCardNumber}</p>}
           </div>
           <div className="text-right">
             <div className="text-xs text-indigo-100">本月实发</div>

frontend/src/pages/portal/Payslip.tsx

@@ -55,7 +55,7 @@ export default function Payslip() {
     const url = URL.createObjectURL(blob)
     const a = document.createElement('a')
     a.href = url
-    a.download = `工资条_${employee.name || '员工'}_${new Date().toISOString().slice(0, 10)}.csv`
+    a.download = `工资条_${employee.name || '员工'}${employee.idCardNumber ? `_${employee.idCardNumber}` : ''}_${new Date().toISOString().slice(0, 10)}.csv`
     a.click()
     URL.revokeObjectURL(url)
   }