Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

Similar to how 'find' works in a text editor, I sometimes need to find a certain string in the agent's output.

This does not seem possible in the TUI at the moment.

Some possible inspirations to look at for designing such a feature:

1. vim (both normal buffers and vim's terminal buffer)
2. tmux

Also, ghostty community has had some interesting conversations about their design of the scrollback search feature: ghostty-org/ghostty#189