feat(fal): support basic fal profiles

[efiop]

Currently one needs to either login or keep using FAL_KEY env vars either implicitly or explicitly, but both can lead to confusion. In my case I find myself generating new keys all the time, because I can't remember which one was which. This PR introduces

• ~/.fal/config.toml or FAL_CONFIG_PATH with profile sections
• FAL_PROFILE to set particular profile

which allows keeping keys in one place and then easily switching between them, similar to tools like aws cli or modal.

In the future we can also use this for acquiring list of teams that your account has access to and switching between them, similar to modal profile.

[squat]

Instead of ~/.fal/config.toml can we default the config path to the more modern and manageable and less sprawling ~/.config/fal.toml( or ~/.config/fal/... in case there are more config files)? Also, rather than defaulting this to a hardcoded path, it would be best IMO to use whatever default is the convention for the given platform. E.g. on Linux the convention is to put app-specific config in ~/.config, anything else is weird, but this might be different for MacOS. So we could use https://pypi.org/project/platformdirs/ to automate this.

[efiop]

@squat I'm familiar with platformdirs/appdirs and used them before heavily, but I would say that they are more confusing for cli applications. They are great for GUI and other stuff as they obide XDG conventions, but it gets way more confusing for simple cli-oriented applications and I would rather not use them.

[squat]

I ultimately don't care about platformdirs itself. My point is about using a config location that conforms to standards and user expectations, i.e. ~/.config/... (at least on Linux)

[efiop]

@squat The expectation is to have ~/.fal really, similar to ~/.aws. I totally understand your point about complying with the current best practices and not polluting the home dir and that IS what we all should do when working on system-programming kinds of tools, but my experience with user-facing cli tools tells me that it is better to keep it simple and in the home dir directly across all platforms. I was a big advocate of doing it properly and using appdirs/platformdirs and I did that for many years, and my conclusion is to KISS and keep it directly in home dir when working on user-facing cli tools.

[chamini2]

Cool!

BTW, I agree we should just keep it in ~/.fal dir. if you are expected to modify the config, it should be very easy to find. Also, we already create the directory for Auth0 token

[efiop]

oops, accident