configurable diff tool

[cserby]

It'd be nice to select the diff tool to be used. I'd love to use vimdiff, and not familiar with git-delta.

[darksworm]

To properly support any diff tool, specifically interactive ones, we would probably have to run it inside a pty.

Unfortunately using a pty is not an option, because the support for that in bun is terrible. I've wasted many hours on it, and eventually decided to write a custom pager instead of dealing with those issues.

For now, this shall live in a "wont fix" category, unless there is enough 👍 on the issue - that might make me reconsider.