[Enhancement] Preserve suspend flag when rewriting POP revive retry records

### Before Creating the Enhancement Request

- [x] I have confirmed that this should be classified as an enhancement rather than a bug/feature.

### Summary

Preserve the POP suspend flag when revive retry records are rewritten or converted, so suspended retries do not later increment reconsumeTimes as normal retries.

### Motivation

Some POP revive paths rebuild PopConsumerRecord or PopCheckPoint during backoff/retry handling. If suspend is not copied, it defaults to false and changes the retry semantics.

### Describe the Solution You'd Like

Copy suspend in the POP revive backoff rewrite paths and KV-to-FS transfer path, with regression tests covering the rewritten records/checkpoints.

### Describe Alternatives You've Considered

No

### Additional Context

_No response_

Search for PopConsumerRecord and PopCheckPoint construction in the POP revive backoff rewrite paths and the KV-to-FS transfer path. Review the existing regression tests first; done means rewritten records and checkpoints retain the suspend flag and the new tests pass.

Written by the indexing model from the issue text.