feat: 优化

frontend/app/web-gold/src/views/material/MaterialListNew.vue

@@ -406,10 +406,16 @@ const handleSaveGroupName = async (group) => {
 const handleDeleteGroup = async (group, event) => {
   event?.stopPropagation?.()
 
+  // 校验：分组内还有文件时不允许删除
+  if (group.fileCount > 0) {
+    message.warning(`分组「${group.name}」内还有 ${group.fileCount} 个文件，请先删除文件后再删除分组`)
+    return
+  }
+
   const confirmed = await new Promise((resolve) => {
     Modal.confirm({
       title: '删除分组',
-      content: `确定要删除分组「${group.name}」吗？删除后该分组下的所有文件将被移动到默认分组。此操作不可恢复。`,
+      content: `确定要删除分组「${group.name}」吗？此操作不可恢复。`,
       okText: '确认删除',
       cancelText: '取消',
       okType: 'danger',