Feat: Let system variables appear in operator prompts #3221 (#8154)

### What problem does this PR solve?
Feat: Let system variables appear in operator prompts #3221

### Type of change


- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/agent/chat/box.tsx

@@ -35,7 +35,7 @@ const AgentChatBox = () => {
   return (
     <>
       <section className="flex flex-1 flex-col pl-5 h-[90vh]">
-        <div className="flex-1 ">
+        <div className="flex-1 overflow-auto">
           <div>
             <Spin spinning={loading}>
               {derivedMessages?.map((message, i) => {