重构消息通知弹窗

frontend/src/pages/System/User/List/components/EditModal.tsx

@@ -201,8 +201,8 @@ const EditModal: React.FC<EditModalProps> = ({
           <div className="grid gap-2">
             <Label htmlFor="department">所属部门</Label>
             <Select
-              value={formData.departmentId?.toString() || undefined}
-              onValueChange={(value) => setFormData({ ...formData, departmentId: Number(value) })}
+              value={formData.departmentId?.toString() || ''}
+              onValueChange={(value) => setFormData({ ...formData, departmentId: value ? Number(value) : undefined })}
             >
               <SelectTrigger>
                 <SelectValue placeholder="请选择所属部门" />