- Add a "remote" thread store implementation
- Implement the remote thread store as a thin wrapper that makes grpc
calls to a configurable service endpoint
- Implement only the thread/list method to start
- Encode the grpc method/param shape as protobufs in the remote
implementation
A wart: the proto generation script is an "example" binary target. This
is an example target only because Cargo lets examples use
dev-dependencies, which keeps tonic-prost-build out of the normal
codex-thread-store dependency surface. A regular bin would either need
to add proto generation deps as normal runtime deps, or use a
feature-gated optional dep, which this repo’s manifest checks explicitly
reject.