- Introduced a new `ClusterManager` to handle cluster membership events and facilitate event replication across relay peers.
- Implemented HTTP endpoints for retrieving the latest serial and fetching events within a specified range.
- Enhanced event handling to process cluster membership events (Kind 39108) and update relay lists accordingly.
- Updated configuration to support cluster administrators and their management capabilities.
- Added comprehensive tests to validate the new cluster replication functionalities.
- Documented the cluster replication protocol in a new specification file.
- Bumped version to reflect these changes.