Port from C

A construct mapping and a boundary, nothing else

This skill maps C semantics 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 — a codebase using RAII, templates, or the STL is /port-from-cpp even when it compiles as C.

The end state, and why C is almost always C

/port-to-rust names three end states; in C terms: A, a standalone Rust binary or library that replaces the C entirely; B, a Rust core with a permanent C-callable surface — the right end state when other C code links this library and will keep doing so; and C, an FFI seam that carries the migration module by module, deleted at cut-over. C codebases are rarely replaced in one step, so C is the common end state and B is common for libraries; the two are distinguished by one question — will any C code still be calling this after the port finishes? Seam mechanics: BOUNDARY.md.