优化分类树加载逻辑，新增批量查询子节点接口以减少数据库往返，提升性能。重构相关服务和控制器，确保系统的可维护性和扩展性。

jeecgboot-vue3/src/views/xslmes/mesXslWarehouse/MesXslWarehouseList.vue

@@ -294,9 +294,8 @@
   async function loadCategoryTree() {
     treeLoading.value = true;
     try {
-      const root = await fetchWarehouseCategoryRoot();
+      const [root, res] = await Promise.all([fetchWarehouseCategoryRoot(), loadCategoryTreeRoot({ async: false, pcode: 'XSLMES_WH' })]);
       warehouseCategoryRootId.value = root?.id != null ? String(root.id) : '';
-      const res = await loadCategoryTreeRoot({ async: false, pcode: 'XSLMES_WH' });
       rawWarehouseCategoryTree.value = Array.isArray(res) ? res : [];
       if (!warehouseCategoryRootId.value || !rawWarehouseCategoryTree.value.length) {
         createMessage.warning('未加载到仓库分类树，请确认已执行库脚本并已在「分类字典」中维护根节点 XSLMES_WH。');
@@ -385,6 +384,8 @@
       title: '仓库管理',
       api: list,
       columns,
+      // 避免：表格默认 immediate 请求一次 + onMounted 末尾 reload 再请求一次（进入页列表闪两次）
+      immediate: false,
       canResize: true,
       formConfig: {
         schemas: searchFormSchema,