feat: reduce maximum description length in CreateFolderDialog to improve user input validation

--bug=1057414 --user=刘瑞斌 【工具】文件夹描述=256，保存时报错 https://www.tapd.cn/62980211/s/1718745

Author: liuruibin

ui/src/components/folder-tree/CreateFolderDialog.vue

@@ -29,7 +29,7 @@
           v-model="folderForm.desc"
           type="textarea"
           :placeholder="$t('components.folder.descriptionPlaceholder')"
-          maxlength="256"
+          maxlength="128"
           show-word-limit
           :autosize="{ minRows: 3 }"
           @blur="folderForm.desc = folderForm.desc.trim()"