## Summary
- migrate exec-server remote registration naming from executor to
environment
- align CLI, public Rust exports, registry error messages, and relay
test fixtures with the environment registry contract
- keep the live registration path and response model consistent with
`/cloud/environment/{environment_id}/register`
## Verification
- `cargo test -p codex-exec-server
remote::tests::register_environment_posts_with_auth_provider_headers
--manifest-path /Users/richardlee/code/codex/codex-rs/Cargo.toml`
- `cargo test -p codex-exec-server --test relay
multiplexed_remote_environment_routes_independent_virtual_streams
--manifest-path /Users/richardlee/code/codex/codex-rs/Cargo.toml`
- `cargo check -p codex-cli --manifest-path
/Users/richardlee/code/codex/codex-rs/Cargo.toml` (still running when PR
opened; will update after completion if needed)
## Why
Exec-server websocket handling had separate reader and writer tasks for
the same socket. That made websocket control-frame handling asymmetric:
the task reading frames could observe `Ping`, but the task allowed to
write frames was elsewhere. This PR moves each physical websocket onto
one always-running pump so the socket owner can handle application
frames and websocket control frames together.
## What changed
- Refactored direct exec-server websocket connections in `connection.rs`
to use one task that owns the websocket for outbound JSON-RPC, inbound
JSON-RPC, periodic keepalive pings, and `Ping` -> `Pong` replies.
- Refactored relay websocket handling in `relay.rs` the same way for
both the harness-side logical connection and the multiplexed executor
physical socket.
- Preserved the existing keepalive ownership policy: outbound direct
websocket clients still send periodic pings, inbound Axum accepts only
reply with pongs, and relay physical websocket endpoints keep their
existing periodic pings.
- Added focused websocket pump tests for ping/pong, binary JSON-RPC,
relay data, malformed relay text frames, and close/disconnect behavior.
- Reconnect behavior is intentionally left for a follow-up.
## Validation
- Devbox Bazel focused unit target:
- `//codex-rs/exec-server:exec-server-unit-tests
--test_filter='websocket_connection_|harness_connection_|multiplexed_executor_'`
## Why
Remote exec-server now needs one executor websocket to serve multiple
harness JSON-RPC sessions. Rendezvous routes by `stream_id`, and the
exec-server side needs to use the same stable relay frame contract
instead of a hand-rolled JSON shape.
The relay protocol also needs to make ownership boundaries clear:
harness and executor endpoints own sequencing, acks, retries, duplicate
suppression, segmentation, and reassembly; rendezvous only routes
frames.
## What Changed
- Add the checked-in `codex.exec_server.relay.v1.RelayMessageFrame`
proto plus generated prost bindings for `codex-exec-server`.
- Encode remote harness/executor relay traffic as binary protobuf
websocket frames while keeping local websocket JSON-RPC unchanged.
- Demux executor-side relay streams into independent
`ConnectionProcessor` sessions keyed by `stream_id`.
- Add a programmatic `RemoteExecutorConfig::with_bearer_token(...)`
constructor for non-CLI callers and integration tests.
- Add an integration test that starts the remote executor against a fake
registry/rendezvous websocket and verifies two virtual streams share one
executor websocket without cross-talk, including per-stream reset
behavior.
- Document the remote relay envelope, sequence ranges, `ack`/`ack_bits`,
and endpoint responsibilities in `exec-server/README.md`.
## Verification
- `cargo test -p codex-exec-server --test relay
multiplexed_remote_executor_routes_independent_virtual_streams --
--exact`
- `cargo test -p codex-exec-server --test relay`
- `cargo test -p codex-exec-server` passed outside the sandbox. The
sandboxed run hit macOS `sandbox-exec: sandbox_apply: Operation not
permitted` in filesystem sandbox tests.
