Provenance of the golden vectors in tests/vectors.txt.

Generate with (from a checkout of the original C++ OmniVox tree, which provides common.h, include/, cereal/, asio/, cryptopp/; requires libcryptopp.a and system fmt):

    g++ -std=c++20 -O1 -DDEBUG -I<cpp-root> -I<cpp-root>/include \
        -I<cpp-root>/cereal/include -I<cpp-root>/asio/include -I<cpp-root>/cryptopp \
        $(pkg-config --cflags fmt) reference/cppgen.cpp \
        <cpp-root>/cryptopp/libcryptopp.a $(pkg-config --libs fmt) -lpthread

The scrypt derivations take ~1 s and 128 MiB each. Any change to these
bytes means the Rust port has regressed against the original.