[Feature]: Sticky copy button for long code blocks

[RobbyV2]

Small UX request: ChatGPT keeps the code block header/copy button sticky at the top while scrolling through a long code block.

Would be nice to have the same behavior in T3 Code. Makes copying long outputs much easier.

Below are screenshots of ChatGPT's UI:

Standard visual/;

When scrolling down slightly (what t3 code currently doesn't do)/;

[alkrobinson]

A bottom copy button would also solve the problem either is acceptable. Willing to implement if needed.