Fix sharded pubsub auto-resubscription after Redis cluster rebalancing

[byunjuneseok]

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Summary

Fixes missing auto-resubscription for Sharded Pub/Sub after Redis cluster rebalancing.

Issues

• No resubscribe mechanism on slot movement (https://github.com/redis/lettuce/issues/3213)

Fixes

• Introduced ShardedPubSubAutoResubscribeListener for automatic resubscribe
• Tracked intentional unsubscribes in async/reactive sunsubscribe
• Leveraged existing cluster redirection for reconnection

Result

Sharded Pub/Sub subscriptions now automatically resubscribe on slot rebalancing while preserving intentional client unsubscribe behavior.

[byunjuneseok]

@tishun // Hi, I noticed this PR is marked for 7.0.0.RELEASE. Just wondering if there’s anything I can do to help move this forward?

Best,