S3-native distributed tracing with no index to maintain and TraceQL for structural queries

Istiod is the single-binary control plane that merges Pilot, Citadel, and Galley. It compiles routing rules into Envoy xDS configuration and pushes it to every sidecar over gRPC streaming.

Two replicas can find their differences in O(log N) hash comparisons instead of comparing every record. Compare root hashes, recurse into the subtree that differs, and narrow down to exactly the divergent blocks