Unknown command reports "error: too many arguments. Expected 0 arguments but got 1"

[yashwanthkamana]

Hi! I hit an issue when running an unknown command. The error message appears
to be about arguments rather than an unknown command.

Steps to reproduce

1. Create a Pastel app with a single index command (no subcommands).
2. Run an unknown command:

my-cli does-not-exist

Expected

An "unknown command" error (and/or a list of available commands).

Actual

error: too many arguments. Expected 0 arguments but got 1

Why this matters

This looks like a misclassification of the error, so users get a confusing
message that suggests they passed too many args instead of an invalid command.