Althoughhttps://github.com/cdr/cli offers a minimal wrapper, it's becoming clear that it lacks sufficient features for the growing scope ofcoder-cli. I propose we migrate tohttps://github.com/spf13/cobrahttps://github.com/urfave/cli. Consider a few advantages that we'll gain "out of the box".

• Suggestions when "unknown command" happens
• bash, zsh, fish, and powershell completion generation
• well designed and standard command validation abstractions
• better persistent flag abstractions
• no more interface upgrading nonsense
• the model of a separate type per command is flawed and, given the lack of generics, is very difficult to abstract

Any thoughts / objections? cc@scsmithr@nhooyr@ammario