fix: remove chat variable in workflow mode (#18696)

web/app/components/workflow-app/components/workflow-header/chat-variable-trigger.tsx

 import {
   useNodesReadOnly,
 } from '@/app/components/workflow/hooks'
+import { useIsChatMode } from '../../hooks'
 
 const ChatVariableTrigger = () => {
   const { nodesReadOnly } = useNodesReadOnly()
+  const isChatMode = useIsChatMode()
+
+  if (!isChatMode)
+    return null
+
   return <ChatVariableButton disabled={nodesReadOnly} />
 }
 export default memo(ChatVariableTrigger)

web/app/components/workflow-app/components/workflow-panel.tsx

         )
       }
       {
-        showChatVariablePanel && (
+        showChatVariablePanel && isChatMode && (
           <ChatVariablePanel />
         )
       }