The consumption side of shared durable queues:
- Thread `shared` through BundleTrigger::Queue + QueueTriggerSpec + the
trigger identity; validate_bundle_for requires a shared queue on a group
to name a declared kind='queue' collection (a shared queue on an app is
rejected by the existing app-owner shared guard).
- materialize: a shared queue template materializes a consumer per
descendant (the M5 one-consumer-slot skip is bypassed for shared —
competing consumers are intended; each descendant gets one copy).
- dispatcher: ActiveQueueConsumer gains shared_group (from the materialized
copy's source template via LEFT JOIN); dispatch_one_queue +
handle_queue_failure route claim/ack/nack/terminal to the group store
when shared_group is Some, via q_claim/q_ack/q_nack/q_terminal helpers. A
group claim is normalized to a ClaimedMessage under the consuming app so
the handler path is unchanged; the reclaim task also drains the group
store. Exhausted shared messages are dropped (no group dead-letter store
yet — documented deferral).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>