argparse.ArgumentParser.parse_args() accepts any Iterable[str], not
just Sequence[str]. The latest typeshed reflects this with the signature
`def parse_args(args: Iterable[str] | None = ...) -> Namespace`.
Update all main(argv:) parameters from `Sequence[str] | None` to
`Iterable[str] | None` and adjust imports accordingly.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>