refactor: 重构WebSocket服务及相关实体类

重构WebSocket服务名称从WebSocketService改为WebSocketClientService，并实现Serializable接口
添加WebSocket常量定义和消息处理实现
优化实体类equals和hashCode方法
修复控制器路径和日志配置
添加查询服务和任务接口方法

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

@@ -1,4 +1,15 @@
 package com.ecep.contract.service;
 
+import org.springframework.context.annotation.Lazy;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDate;
+
+@Lazy
+@Service
 public class HolidayService {
+
+    public LocalDate adjustToWorkDay(LocalDate date) {
+        throw new RuntimeException("Not implemented");
+    }
 }