## Why
Remote executors need to recover from confirmed authentication-service outages and spread reconnect attempts after a shared outage. Registration retries must remain limited to confirmed failures before a write, since replaying an ambiguous request can replace a newer registration.
## What changed
- Retry registry responses with HTTP 502 and `authentication_service_unavailable`, alongside the existing HTTP 503 `registration_conflict` retries.
- Accept structured registry errors in `detail`, keeping the canonical `error` authoritative when both are present.
- Randomize reconnect delays between half and all of the current exponential backoff, retaining the 30-second cap.
## Testing
Add coverage for reconnect jitter bounds, authentication-outage retry cancellation, error-envelope precedence, and preservation of Noise identity and initialized sessions across retries. Make the HTTP-header helper cleanup test wait for the helper PID before cancellation and verify process termination when the provider is dropped.
GitOrigin-RevId: 35fdb57732d17b0bbfeca8a4dc557a0988e29a31
## Why
Private IP destinations always bypassed inherited upstream proxies, preventing their use for private networks reachable through an upstream VPN proxy.
## What changed
- Add `codex exec-server --proxy-private-ips-via-upstream`, also configurable with `CODEX_EXEC_SERVER_PROXY_PRIVATE_IPS_VIA_UPSTREAM=true`. The setting defaults to disabled.
- Allow permitted RFC 1918, carrier-grade NAT, and IPv6 unique-local destinations to use an applicable upstream proxy. Loopback and link-local destinations retain direct routing, and destination access policy still applies.
- Keep connections direct when no valid upstream proxy applies or `allow_upstream_proxy=false`. Errors after selecting an upstream proxy do not trigger a direct retry.
- Rename `ExecServerRuntimePaths` to `ExecServerRuntimeOptions` and carry the routing setting from executor startup into the managed network proxy.
## Testing
Add routing coverage for private address ranges, special-use addresses, and public targets with the option enabled and disabled. Verify that HTTP and CONNECT requests still enforce destination allowlists and denylists, and update the CLI help snapshot.
GitOrigin-RevId: b7c9cc7da0e0f545694a6521b74c9b36b7b92769
## Why
Remote environment registration can return an explicit `503` `registration_conflict` after the registry finishes its own recovery attempts. Retrying ambiguous failures is unsafe because a timed-out request may still have replaced a newer registration.
## What changed
- Retry only explicit `registration_conflict` responses with jittered backoff, both during initial registration and after a rejected relay connection.
- Apply the existing connection timeout to the complete registration attempt, including response-body diagnostics.
- Keep retry waits and in-flight requests cancellable while preserving the Noise identity and initialized session across successful recovery.
## Testing
Added unit coverage for retry eligibility and timeout handling, plus relay tests for identity and session preservation and prompt shutdown during registration.
GitOrigin-RevId: 374e6fdac4755f377cbea9400c76a228b790945a
Anton Panasenko