## What changed
- Add `x-cluster-name` from `OPENAI_CLUSTER` and
`x-openai-internal-caller` from `DD_SERVICE` to rendezvous WebSocket
handshakes when the environment values are nonempty and valid HTTP header
values.
- Apply the rendezvous headers to both client and remote executor connections
while preserving the existing W3C trace context headers.
GitOrigin-RevId: fead0244ba24fa208990b92d2170a9ae76ff2ceb
## What changed
- Rename `ReqwestHttpClient` to `RouteAwareHttpClient` to reflect that delegated HTTP uses Codex's shared route-aware transport.
- Use `codex_http_client` response and error types plus transport-neutral `http` and `url` types, removing the exec server's direct `reqwest` dependency.
## Testing
- Cover fragment stripping and Unicode hostname normalization for delegated HTTP requests.
GitOrigin-RevId: 8b0fc60a76004feb57198bfb4afb1371c9ceb1bd
## Summary
- Record bounded duration and outcome metrics for remote environment
registration and Noise rendezvous connection attempts.
- Count reconnects by bounded reason: disconnect, connection failure, or
rejected registration.
- Trace registration at the owning client boundary without exporting raw
environment or registration identifiers.
- Replace the stale pre-Noise WebSocket observability design with the
current remote transport model.
## Stack
Review and land this stack in order:
1. #27466 — trace exec-server JSON-RPC requests
2. #27467 — record bounded connection, request, and process lifecycle
metrics
3. #27470 — observe remote registration and Noise rendezvous lifecycle
**(this PR)**
## Validation
- `just test -p codex-exec-server --lib` (149 passed)
- `just test -p codex-cli --test exec_server` (4 passed)
- `just argument-comment-lint`
- `just bazel-lock-check`
- `just fix -p codex-exec-server -p codex-cli`
- `just fmt`
