Pause Codex retries while local network is unavailable

Summary

Codex currently spends retry attempts even when the local machine has no usable network route. If Wi-Fi/Ethernet/VPN/tethering drops during an active turn, Codex should wait for the device to come back online before starting the next retry attempt.

Expected behavior

• If a retryable API/stream error happens and the local device has no usable network route, Codex should pause before the next retry.
• While paused, user-facing surfaces should show a clear waiting status instead of burning through Reconnecting... n/N.
• Once the local network route returns, Codex should continue with the existing retry/fallback behavior.
• If network availability cannot be determined, Codex should avoid deadlocking and proceed with the existing retry behavior.

Reproduction sketch

1. Start a Codex turn that is actively Thinking/Working.
2. Disable local network connectivity, for example by turning Wi-Fi off and disconnecting Ethernet/VPN.
3. Wait for the current request/stream to fail.
4. Observe Codex retrying according to backoff/max retry counters even though no local network route is available.

Related issues

• #12595
• #22010
• #24045
• #11680