Module scheduling 

Scheduling and queue management (Section 12).

Manages PendingVerify, FetchQueue, and InFlightFetch queues for the replication pipeline. Each key progresses through at most one queue at a time, with strict dedup across all three stages.

Structs

InFlightEntry

An in-flight fetch entry tracking an active download.

ReplicationQueues

Central queue manager for the replication pipeline.