refactor(auth): 菜单路由为空时默认返回空列表而非 null

Closes #IB9UDW

continew-module-system/src/main/java/top/continew/admin/auth/service/impl/LoginServiceImpl.java

@@ -178,6 +178,9 @@ public class LoginServiceImpl implements LoginService {
             roleCodeSet.forEach(roleCode -> menuSet.addAll(menuService.listByRoleCode(roleCode)));
         }
         List<MenuResp> menuList = menuSet.stream().filter(m -> !MenuTypeEnum.BUTTON.equals(m.getType())).toList();
+        if (CollUtil.isEmpty(menuList)) {
+            return new ArrayList<>(0);
+        }
         // 构建路由树
         TreeField treeField = MenuResp.class.getDeclaredAnnotation(TreeField.class);
         TreeNodeConfig treeNodeConfig = crudProperties.getTree().genTreeNodeConfig(treeField);