fix: CustomLeftMenu 点击项后不再误重置到第一页

仅在搜索、pageSize 或条目总数变化时重置分页，避免 mapCount 等字段更新触发 treeData 重建导致跳页。

src/components/CustomLeftMenu/index.vue

@@ -194,12 +194,25 @@
     },
   );
   watch(
-    () => [props.treeData, props.searchKeyword, props.pageSize],
+    () => props.searchKeyword,
     () => {
-      innerCurrentPage.value = 1;
-      emit('update:currentPage', 1);
+      setCurrentPage(1);
+    },
+  );
+  watch(
+    () => props.pageSize,
+    () => {
+      setCurrentPage(1);
+    },
+  );
+  /** 条目数变化（搜索过滤、增删类型）时才回到第一页；节点字段更新（如 mapCount）不重置 */
+  watch(
+    () => paginateEntries.value.length,
+    (len, prevLen) => {
+      if (prevLen !== undefined && len !== prevLen) {
+        setCurrentPage(1);
+      }
     },
-    { deep: true },
   );
   watch(
     () => paginationMeta.value.totalPages,