refactor(income-proof): 优化收入证明单据插件继承结构和字段处理逻辑

- 将继承类从 AbstractHcssBaseFormPlugin 改为 AbstractBillPlugIn
- 移除未使用的导入包 FieldsHandle、HandleTypeEnum 和 AbstractHcssBaseFormPlugin
- 简化字段启用逻辑，直接使用 getView().setEnable 替代 FieldsHandle 处理
- 移除 getSalaryItemsForSql 方法中的冗余注释
- 添加 AbstractBillPlugIn 必需的导入包

code/swc/nckd-jxccl-swc/src/main/java/nckd/jxccl/swc/hcss/formplugin/IncomeProofBillExPlugin.java

@@ -1,6 +1,7 @@
 package nckd.jxccl.swc.hcss.formplugin;
 
 import kd.bos.algo.DataSet;
+import kd.bos.bill.AbstractBillPlugIn;
 import kd.bos.dataentity.entity.DynamicObject;
 import kd.bos.dataentity.entity.DynamicObjectCollection;
 import kd.bos.db.DB;
@@ -13,9 +14,6 @@ import kd.bos.logging.Log;
 import kd.bos.logging.LogFactory;
 import kd.bos.orm.ORM;
 import kd.bos.servicehelper.parameter.SystemParamServiceHelper;
-import kd.swc.hcss.business.handle.action.FieldsHandle;
-import kd.swc.hcss.common.enums.HandleTypeEnum;
-import kd.swc.hcss.formplugin.web.AbstractHcssBaseFormPlugin;
 import nckd.jxccl.swc.utils.SwcUtils;
 import java.math.BigDecimal;
 import java.math.RoundingMode;
@@ -33,7 +31,7 @@ import java.util.*;
  * 描述 自定义收入证明项目获取计算
  */
 @SuppressWarnings("unused")
-public class IncomeProofBillExPlugin extends AbstractHcssBaseFormPlugin {
+public class IncomeProofBillExPlugin extends AbstractBillPlugIn {
 
     private static String IncomeProofBill_CustomItems;
     private static String IncomeProofBill_SalaryItems;
@@ -65,8 +63,7 @@ public class IncomeProofBillExPlugin extends AbstractHcssBaseFormPlugin {
         if ("checkapprove".equals(formOp)) {
             isExistCustomItems = isExistCustomItems(data);
         } else if ("modify".equals(formOp)) {
-            FieldsHandle handle = (FieldsHandle)this.getViewHandle(HandleTypeEnum.FIELDS_HANDLE);
-            handle.setEnable(this.getView(), Collections.singletonList("nckd_daterange"), Boolean.TRUE);
+            this.getView().setEnable(Boolean.TRUE, "nckd_daterange");
         }
 
         super.beforeDoOperation(args);
@@ -155,7 +152,7 @@ public class IncomeProofBillExPlugin extends AbstractHcssBaseFormPlugin {
 
     public String getSalaryItemsForSql() {
         if (IncomeProofBill_SalaryItems == null || IncomeProofBill_SalaryItems.trim().isEmpty()) {
-            return "''"; // 返回空字符串的 SQL 格式
+            return "''";
         }
 
         String[] items = IncomeProofBill_SalaryItems.split(",");