fix(reth-bench): return error instead of panic on invalid payload
Previously, reth-bench new-payload-fcu would panic when receiving an
Invalid payload status. Now it returns a proper error, allowing the
benchmark to report the failure gracefully.
Amp-Thread-ID: https://ampcode.com/threads/T-019c06fd-0866-7318-88e1-4094c1b72f80
Co-authored-by: Amp <amp@ampcode.com>
perf: use biased select and prioritize engine events
Use biased select in the main engine loop to always poll engine_service first,
ensuring engine events are processed with priority over built payloads and
shutdown requests.
Amp-Thread-ID: https://ampcode.com/threads/T-019c06cf-3a1d-757d-a219-7b86451674ab
Co-authored-by: Amp <amp@ampcode.com>