PartitionLog

A Log view bound to a single partition: the partition-indexed operations with the index pre-applied, so a per-partition consumer holds its slice of the log without threading the partition through every call.

Deliberately not the whole Log surface — the database-level operations (Log.openGroupSubscription, one consumer-group membership per database, and Log.epoch) belong to the shared log, reached through DatabaseLogs, not to a single partition's view.