feat(portal): add customContainer prop to PortalToFollowElem for flexible rendering

web/app/components/app-sidebar/dataset-info/dropdown.tsx

       } : {
         mainAxis: 4,
       }}
+      customContainer={document.body}
     >
       <PortalToFollowElemTrigger onClick={handleTrigger}>
         <ActionButton className={cn(expand ? 'size-8 rounded-lg' : 'size-6 rounded-md')}>

web/app/components/base/portal-to-follow-elem/index.tsx

   offset?: number | OffsetOptions
   onOpenChange?: (open: boolean) => void
   triggerPopupSameWidth?: boolean
+  customContainer?: HTMLElement | null
 }
 
 export function usePortalToFollowElem({
   offset: offsetValue = 0,
   onOpenChange: setControlledOpen,
   triggerPopupSameWidth,
+  customContainer = null,
 }: PortalToFollowElemOptions = {}) {
-  const container = document.getElementById('workflow-container') || document.body
+  const container = customContainer || document.getElementById('workflow-container') || document.body
   const [localOpen, setLocalOpen] = useState(false)
   const open = controlledOpen ?? localOpen
   const handleOpenChange = useCallback((newOpen: boolean) => {

web/app/components/datasets/create-from-pipeline/list/template-card/operations.tsx

           onClick={onClickExport}
         >
           <span className='system-md-regular px-1 text-text-secondary'>
-            {t('datasetPipeline.operations.exportDSL')}
+            {t('datasetPipeline.operations.exportPipeline')}
           </span>
         </div>
       </div>

web/i18n/en-US/dataset-pipeline.ts

     choose: 'Choose',
     details: 'Details',
     editInfo: 'Edit info',
-    exportDSL: 'Export DSL',
     useTemplate: 'Use this Knowledge Pipeline',
     backToDataSource: 'Back to Data Source',
     process: 'Process',

web/i18n/zh-Hans/dataset-pipeline.ts

     choose: '选择',
     details: '详情',
     editInfo: '编辑信息',
-    exportDSL: '导出 DSL',
     useTemplate: '使用此知识流水线',
     backToDataSource: '返回数据源',
     process: '处理',