feat: 添加VendorGroupRequireFileTypeVo及相关服务功能

refactor: 重构多个服务类和方法，优化代码结构
fix: 修复PermissionVo中code字段更名为key的问题
docs: 更新create_vo.md文档，添加新创建的VO记录
perf: 优化WebSocketClientService中的session关闭逻辑
style: 清理无用导入和注释，统一代码格式

client/src/main/java/com/ecep/contract/service/ProjectCostItemService.java

@@ -1,17 +1,19 @@
 package com.ecep.contract.service;
 
+import java.util.List;
+
+import org.springframework.data.domain.Pageable;
+import org.springframework.stereotype.Service;
+
+import com.ecep.contract.util.ParamUtils;
 import com.ecep.contract.vm.ProjectCostItemViewModel;
 import com.ecep.contract.vo.ProjectCostItemVo;
 import com.ecep.contract.vo.ProjectCostVo;
-import org.springframework.stereotype.Service;
-
-import java.util.List;
 
 @Service
 public class ProjectCostItemService extends QueryService<ProjectCostItemVo, ProjectCostItemViewModel> {
 
     public List<ProjectCostItemVo> findByCost(ProjectCostVo cost) {
-        // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'findByCost'");
+        return findAll(ParamUtils.builder().equals("cost", cost).build(), Pageable.unpaged()).getContent();
     }
 }