Protobuf descriptor types for [buffa](https://crates.io/crates/buffa).
This crate provides self-hosted Rust types for `google/protobuf/descriptor.proto`
and `google/protobuf/compiler/plugin.proto`, generated by buffa-codegen itself.
It underpins both compile-time code generation and runtime reflection.
The only runtime dependency is `buffa` — no external protobuf library required.