feat(tui): add shortcut for clearing task logs (#10828)
### Description
I use turborepo for long running `dev` tasks and sometimes I want to
clear the output of just one pane, for example server logs before
triggering a request.
If I clear my terminal buffer it clears everything including the TUI,
and the content is still there to be scrolled to. What I really want is
to only clear the logs for a single task.
This PR introduces the "Clear logs" option, currently bound to `shift-c`
(I tried to pick a shortcut inkeeping with the others). It clears the
logs only for the current task
Example screencasts below
### Testing Instructions
- Run some tasks with the `--ui=tui`
- Press `shift-c` on a pane with output
- See that only that panes output is cleared, and new logs appear as
normal
I attempted to write tests for this but I wasn't keen on all the hoops I
had to jump through to try and test that it actually clears the buffer
**Examples**
Attempting and failing to clear with cmd+k:
https://github.com/user-attachments/assets/d72a304d-c4b8-467b-9c17-16422552610e
New behaviour with shift-c:
https://github.com/user-attachments/assets/00440758-aa16-402f-9119-086639f4fb62
