Feat: Modify the background color of the agent canvas #3221 (#9020)

### What problem does this PR solve?

Feat: Modify the background color of the agent canvas #3221
### Type of change


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

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

@@ -105,7 +105,6 @@ const AgentChatBox = () => {
           <div ref={ref} />
         </div>
         <MessageInput
-          showUploadIcon={false}
           value={value}
           sendLoading={sendLoading}
           disabled={false}