[Caideyipi]

Problem

When a consensus subscription queue was deactivated during leader changes or queue removal, it discarded prefetched and in-flight events. The next poll used client-reported progress, which advances when an event is observed and can be ahead of its ACK. Those events were then skipped without a WAL-gap signal.

Fix

• Initialize replay from the subscription commit manager's committed progress after a queue reset, rather than the poll progress hint.
• Add a regression test proving that an unacknowledged event is replayed after deactivation and reactivation.

This preserves at-least-once delivery across queue lifecycle resets while retaining the existing ACK-based commit frontier.

Validation

• mvn clean test -T 2 -Dtest=ConsensusPrefetchingQueueDeliveryTest,ConsensusPrefetchingQueueTest -Dsurefire.failIfNoSpecifiedTests=false -pl iotdb-core/datanode -am -P with-integration-tests
• 67 tests passed, 0 failures, 0 errors.

[Caideyipi]

Initial self-review passed with no actionable findings; no fixes were needed. Verified with clean-source reactor tests: 67 tests passed, with 0 failures and 0 errors, including the new deactivation replay regression test.

[Caideyipi]

Independent re-review completed for the full current PR diff and relevant context. No source-behavior or test-logic issues were found.

One comment-only finding was fixed in e40e0f0: ConsensusPrefetchingQueue.java:315 still described initialization using a poll progress hint. The comment now describes successful initialization from committed progress (or its fallback), matching the implementation.

Validation: mvn spotless:apply -P with-integration-tests completed successfully, and git diff --check passed. The author-provided remote clean-reactor result is 67 tests passed, 0 failures and 0 errors. The new ConsensusPrefetchingQueueDeliveryTest#testDeactivationReplaysUncommittedEventInsteadOfUsingPollProgress has not been run locally; tests were not rerun for this comment-only fix.

The remote head was verified as e40e0f0. This PR remains open and non-draft under the author's explicit comment-only exception. This session performed one review round.