## Why
Remote environment connections need to honor Codex's effective outbound proxy policy, including when a rendezvous connection reconnects.
## What changed
- Pass the configured `HttpClientFactory` into remote environment transports and use `WebSocketConnector` for exec-server and rendezvous WebSockets.
- Resolve proxy routes asynchronously so these connections can use the configured system proxy.
- Add connector options that preserve Tungstenite's default TLS behavior and enable `TCP_NODELAY` for latency-sensitive rendezvous traffic.
## Testing
- Verify prepared remote environments connect through a configured system proxy.
- Verify initial and reconnected encrypted relay peers use the system proxy.
- Cover default TLS selection and opt-in `TCP_NODELAY` behavior in the WebSocket client.
GitOrigin-RevId: 8a8da2116e37cb3a891269d0c0b037986fecdd3c
## Summary
- add a provider API that supplies a fresh signed WebSocket URL for each
remote exec-server connection
- refresh the signed URL after disconnects and retry once when a
handshake returns `401 Unauthorized`
- allow `EnvironmentManager` consumers to register remote environments
backed by the URL provider
## Tests
- `just test -p codex-exec-server -E
'test(remote_websocket_client_refreshes_url_after_unauthorized_handshake)
| test(remote_websocket_client_refreshes_url_after_disconnect)'` — 2
passed
- `cargo check -p codex-core-api` — passed
- `just fix -p codex-exec-server` — passed
- `just fix -p codex-core-api` — no test targets; no-op
- `just fmt` — passed
- `just test -p codex-exec-server` — 187 passed; 32 unrelated macOS
sandbox tests could not invoke nested `sandbox-exec` (`Operation not
permitted`)