fix: 员工端身份证号显示兼容旧登录——从 home/overview 获取 fallback

- EmployeeHome.tsx: 使用 overview.employeeIdCardNumber 作为 fallback
- PortalLayout.tsx: 获取 overview 数据作为 idCardNumber fallback
- 两者都会在获取到后同步更新 localStorage，避免重复请求

frontend/src/pages/portal/EmployeeHome.tsx

@@ -54,15 +54,24 @@ export default function EmployeeHome() {
   const announcements = overview?.announcements || []
   const attendanceSummary = overview?.attendance
 
+  // 如果 localStorage 中没有 idCardNumber，但 overview 返回了，则更新 localStorage
+  const idCardNumber = employee.idCardNumber || overview?.employeeIdCardNumber
+  if (idCardNumber && !employee.idCardNumber) {
+    try {
+      const updated = { ...employee, idCardNumber }
+      localStorage.setItem('portalEmployee', JSON.stringify(updated))
+    } catch {}
+  }
+
   return (
     <div className="space-y-4">
       {/* 欢迎卡片 */}
       <Card className="bg-gradient-to-br from-indigo-600 to-indigo-700 text-white border-0">
         <div className="flex items-center justify-between">
           <div>
-            <h1 className="text-lg font-bold">你好，{employee.name || '同事'}</h1>
+            <h1 className="text-lg font-bold">你好，{employee.name || overview?.employeeName || '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>}
+            {idCardNumber && <p className="text-xs text-indigo-200 mt-0.5 font-mono">{idCardNumber}</p>}
           </div>
           <div className="text-right">
             <div className="text-xs text-indigo-100">本月实发</div>