Port from C++

A construct mapping and a boundary, nothing else

This skill maps C++ to Rust and owns the C++ boundary. The parity contract, the five phases, and the anti-patterns are /port-to-rust, which runs first and stays running through the port. C is a separate skill — the mechanics overlap, the idioms do not — so a C codebase with a .cpp extension is still /port-from-c territory in everything but the build.

The end state, and the C++ default