Deletes pkg/cpp/ (11 tracked files: consensus.cpp, mlx_consensus.cpp,
chain.cpp, network.cpp, vote_processor.cpp + 2 headers + 2 tests + 2
examples + CMakeLists.txt). The sources are now committed in
~/work/luxcpp/consensus/ (commit 6b43843).
cpp_node.go's hardcoded "pkg/cpp/build" path updated to point at
$HOME/work/luxcpp/consensus/build so the e2e harness still finds the
built artifact in its new home.
Rule: Go repos hold only Go + CGO bindings. Heavy C++/Metal/CUDA
lives in ~/work/luxcpp/<package>/. No mixed-language source trees in
the Go monorepo.
zeekay