OK so I thought that Terminal.app does some kind of clever
left/right paging. Turns out it just wraps lines if they’re
too long, and this wrapping is controlled by some ANSI
control sequence (DECSET 7 and DECRST 7 apparently).
So there are a few things I need to:
- add word wrapping controlled by DECSET 7
- add vertical pagination via up/down arrows
- fix the bug where arrow key presses are not proxied through to the focussed terminal