don't detect tty on stdin

[vito]

• need to detect stdout for obvious reasons
• need to detect stderr because stdout might be piped to something, but we still want to render the fancy UI in that case
• need to not detect stdin to support things like dagger run. use case:
  • want to forward stdin to command to support piping to it
  • don't want it to be treated like a tty because dagger run tui is going to intercept all interactive input anyway, and rendering a fancy UI within a fancy UI doesn't seem wise