[jeremydmiller]

Closes #5236

Problem

KafkaListener.DeferAsync() (and KafkaTopicGroupListener's) called _receiver.ReceivedAsync() directly. When the durable inbox write keeps failing, DurableReceiver.receiveOneAsync settles the delivery by deferring it, from inside its own receive, so the cycle in the reported stack trace never unwinds:

DurableReceiver.receiveOneAsync → KafkaListener.DeferAsync → DurableReceiver.ReceivedAsync → RetryBlock.PostAsync → DurableReceiver.receiveOneAsync → …

The process dies of a stack overflow (exit 139). A latched receiver loops the same way through its _deferBlock. The loop also kept the receiver busy, which got in the way of the drain that PauseForInboxRecoveryAsync runs.

Fix

New KafkaDeferredRedelivery, used by both Kafka listeners:

• DeferAsync returns at once. The envelope goes back to the receiver on its own task, after a short pause (KafkaDeferredRedelivery.Delay, 1 second, internal), so the stack can't grow and a receiver that keeps deferring can't spin.
• It only redelivers while the listener is running. Once the listener stops, including the pause for inbox recovery, the envelope is left alone. Its offset was never completed, so the KafkaOffsetCommitter watermark keeps the committed position below it and the restarted consumer reads it again. Offsets never move past a message that wasn't persisted.

Behavior note: Kafka has no native requeue, so Requeue error policies go through this same path and now redeliver after about 1 second instead of immediately.

Tests

• deferred_redelivery_does_not_recurse_5236 (broker-free): a receiver that defers every envelope, as the failing inbox does. The stack depth stays flat across 20 redeliveries, DeferAsync doesn't wait for the redelivery, and nothing is redelivered after the listener stops.
• Against a local broker + Postgres: duplicate_message_handling_with_postgres_inbox, durable_topic_group_batching_4026, disable_requeueing, commit_strategy_end_to_end, compliance suites: 70/70.
• Pinned wolverine.slnx -c Release -f net9.0 build is clean.

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