Read the API token from LARAVEL_CLOUD_TOKEN and make auth:token scriptable

[joetannenbaum]

There was no way to give the CLI a token without a TTY. cloud auth needs a browser and auth:token --add always prompted, so the only option in CI was hand-writing ~/.config/cloud/config.json at a path that changes with CLOUD_BASE_URL.

The CLI now reads LARAVEL_CLOUD_TOKEN from the environment. It takes precedence over saved tokens and writes nothing to disk. An empty value counts as unset, so you can bypass it for a single command.

auth:token --add and --remove accept --token= or the token piped to stdin, and report the result as JSON when run non-interactively.

The environment holds one token, so it picks its own organization. Naming a different one with --organization now fails rather than quietly using the token's. auth and auth:token --add warn when a token you just saved is being overridden by the environment, and auth:token --list names where each token came from.

This also clears up a few non-interactive dead ends that returned a bare "Required.": adding with no token, removing a token that isn't saved, and running auth:token with no action flag.