Task: Create a GRPC-based service

Investigate GRPC as the runtime substrate for the client/server architecture: build a small prototype, generate the C++ surface, wire it through CMake/vcpkg, and decide whether to adopt.

• A GRPC prototype builds in our toolchain.
• A round-trip call works in tooling.
• We can articulate a clear yes/no on adoption.

GRPC's codegen and build complexity, combined with the size of the GRPC dependency, did not justify its benefits for the project's current scope. The pivot was to Boost.cobalt — coroutine-based async over plain sockets, no IDL, and a much smaller dependency footprint. The follow-on task Remove GRPC support cleaned up the experiment.

• This record exists to preserve provenance. Without it, a future reader might re-investigate GRPC without knowing it was already considered and rejected.
• Demonstrates the v2 ABANDONED state pattern.

• No code merged. GRPC removed from the project.