Reconciles Queue CRs into Kafka topics + Redis shard-map/queue-meta state:
creates shard-0 on first reconcile, splits a shard's hash range into two
children once its split threshold is crossed, drains and closes a parent
shard once its consumer group has fully caught up and its retention
window has elapsed, and tears down every shard's topic + Redis state on
deletion. Includes the manager entrypoint (cmd/queue-operator) and RBAC.
Implements the kmsvc: key schema (inflight, pending/watermark keyed by
shard+partition, vis_index, dedup, fifo_lock, queue meta, shard map) plus
the atomic reap/ack Lua scripts used for safe multi-replica redelivery
and DLQ routing.
Adds queue_service.proto (SendMessage, SendMessageBatch, ReceiveMessage,
DeleteMessage, DeleteMessageBatch, ChangeMessageVisibility(Batch)) with
grpc-gateway REST annotations, plus the generated Go server/client and
gateway stubs.