[AI chat][Response] No "copied" indicator (checkmark) after clicking Copy on user message

[Serg0147]

StatGPT Global Trusted Data Commons version

0.1.0

What steps will reproduce the bug?

1. Go to Welcome page
2. Send any request (e.g. "What data is available?")
3. Hover over your own (user) message
4. Click the Copy icon
5. Pay attention to the Copy icon state after click

What is the expected behavior?

After clicking Copy, the icon changes to a confirmation indicator (checkmark) showing that the text was copied to the clipboard.

What do you see instead?

No confirmation indicator (checkmark) appears after clicking Copy. There is no visual feedback that the message was copied.

Additional information

No response