add terminal component

[prabirshrestha]

With the rise of agents and custom ADE, it would be good if gpui supported terminal components so we can easily render it in our gpui apps.

preferred would be libghostty.

[huacnlee]

Thanks for the suggestion. A terminal component is outside GPUI Kit's scope. There is already a community implementation worth looking at: gpui-ghostty, which integrates Ghostty with GPUI. We'd prefer to leave this to the ecosystem rather than add another terminal implementation to Kit.