[Bug] The dialog page copy function is not working.

### Nexent Version

_No response_

### Problem Description

如果agent未输出最终回答，点击将agent停止后。点击复制按钮，没有复制成功。（是否有必要复制？）
ps agent输出最终回答后，复制是可用的
<img width="3504" height="1845" alt="Image" src="https://github.com/user-attachments/assets/ad818f0d-4799-4764-a056-6bed5cbc3599" />

### Reproduction Steps

_No response_

### Additional Information

_No response_