Release storage/elasticsearch/v0.2.1

session/redis: fix linter and add tests (#374)

- Introduced TestService_AsyncPersisterNum_DefaultClamp to verify
default clamp behavior for async persister number.
- Added TestService_AppendEvent_NoPanic_AfterClose to ensure AppendEvent
does not panic after service closure.
- Implemented TestService_SessionEventLimit_TrimsOldest to confirm that
only the latest events are retained when exceeding the session event
limit.
- Updated AppendEvent method to handle event channel indexing more
robustly and added context cancellation in async worker.