Use writerStreaming() instead of writer() for stdout in helpgen and
main_build_data. The positional writer calls setEndPos/ftruncate in
end(), which fails on Windows because ftruncate on pipes maps
INVALID_PARAMETER to FileTooBig.
Replace scandir with opendir/readdir plus qsort in framegen since
scandir is a POSIX extension not available on Windows.
This was previously applied and reverted upstream (f4998c6ab, 0fdddd5bc)
as collateral from an unrelated example-execution hang that has since
been resolved.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This is stomping towards minimizing our build.zig dependencies so that
it can be cached more often. Right now, touching almost any file in the
project forces the build.zig to rebuild which is destroying my
productivity.
