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 (Lettuce Sharded PubSub Resubscribe Possible Issue #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.