Suite discovery, the extension-point catalog scan, mod test-dir pickup,
and the meta-coverage corpus all shelled out to ls/find/test -d, which do
not exist in cmd.exe. Every listing came back empty on Windows, so tiers
ran 0 suites and still reported ALL TESTS PASSED.
Add portable probes to tests/fs_io.lua (same Unix commands on
Linux/macOS; dir /b and a shell-free rename-self existence check on
Windows) and rewire the four call sites to them. 15/15 engine suites and
2/2 modkit suites now genuinely run and pass on Windows.
Fixes#266
Co-authored-by: johnjohto <johnjohto@users.noreply.github.com>
bryanthaboi