refactor(vo): 重构VO对象结构，统一字段命名和接口实现

重构所有VO对象，统一字段命名规范，移除冗余字段，优化接口实现
新增Voable接口用于VO对象转换
调整BaseViewModel和ProjectBasedViewModel接口定义
更新相关服务和控制器以适应VO对象变更

common/src/main/java/com/ecep/contract/model/PurchaseOrder.java

@@ -4,6 +4,7 @@ import java.time.LocalDateTime;
 import java.util.Objects;
 
 import com.ecep.contract.util.HibernateProxyUtils;
+import com.ecep.contract.vo.PurchaseOrderVo;
 
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
@@ -27,7 +28,7 @@ import lombok.ToString;
 @Entity
 @Table(name = "PURCHASE_ORDER", schema = "supplier_ms")
 @ToString
-public class PurchaseOrder implements IdentityEntity, BasedEntity, ContractBasedEntity, java.io.Serializable {
+public class PurchaseOrder implements IdentityEntity, BasedEntity, ContractBasedEntity, java.io.Serializable, Voable<PurchaseOrderVo> {
     private static final long serialVersionUID = 1L;
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
@@ -116,4 +117,26 @@ public class PurchaseOrder implements IdentityEntity, BasedEntity, ContractBased
     public final int hashCode() {
         return HibernateProxyUtils.hashCode(this);
     }
+
+    @Override
+    public PurchaseOrderVo toVo() {
+        PurchaseOrderVo vo = new PurchaseOrderVo();
+        vo.setId(id);
+        if (contract != null) {
+            vo.setContractId(contract.getId());
+        }
+        vo.setCode(code);
+        // PurchaseOrder中没有name字段，这里可以设置为code
+        vo.setName(code);
+        // PurchaseOrder中没有vendorId字段，只有vendorCode
+        // vo.setVendorId();
+        // PurchaseOrder中没有orderDate字段，这里可以设置为makerDate
+        if (makerDate != null) {
+            vo.setOrderDate(makerDate.toLocalDate());
+        }
+        // PurchaseOrder中没有totalAmount、taxAmount、taxRate和statusId字段，暂时不设置
+        vo.setRemark(description);
+        // active字段默认为false，在PurchaseOrderVo类中已经设置
+        return vo;
+    }
 }