- Add pdftract-dotnet-publish.yaml for NuGet package publishing
- Add pdftract-libpdftract-build.yaml for C FFI library builds
- Both workflows model existing PHP/Ruby publish patterns
- NuGet publish with proper API key and symbol packaging
- C library build using cbindgen and cross-compilation
- Supports all 5 target triples (Linux x64/ARM, macOS x64/ARM, Windows)
- Homebrew formula and vcpkg port generation included
Closes bf-20v7h