Cli::ParseArgs had no test coverage: its only sibling test
(AutorunExitTests) exercises the autorun launcher, not the parser.
Add cli_args_tests covering every option and its side effects, the
--rpath and --exclude-sce-module value consumption (including that the
following token is taken verbatim rather than re-parsed as a flag), the
unused-filter value and single-specification validation, the
--exclude-sce-module/--skip-sce-module conflict in both orders, the
order-independent --windows-diagnostics/--windows-gui requirement on
--windows, unknown-option and extra-positional rejection, and the usage
message when an input or output path is missing.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>