Run matched prompts through the Go and pinned OpenRouter routes either as intentional shadows or as separately selected primary/fallback trials. Keep task text and reasoning constant. Use session route availability and gateway telemetry—not worker self-report—to record requested route, actual serving slug, retries, fallback index, build fingerprint, failure, and latency. Compare outputs with task evidence. This is a route experiment, not a model vote or an automatic failover promise.
