Implement XEX2 main header parsing with module flag decoding.
Add error handling, big-endian read utilities, CLI entry point,
and comprehensive unit + integration tests against a sample file.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Scaffold xex2tractor Rust project with cargo, add MIT license, README,
and XEX2 file format documentation.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>