Add cluster replication configuration and enhance event handling

- Introduced support for cluster replication in the ORLY system, allowing for distributed relay clusters with active replication.
- Updated the configuration to include a new option for propagating privileged events to relay peers.
- Enhanced the `ClusterManager` to manage event propagation based on the new configuration setting.
- Improved the handling of event fetching to respect the propagation settings, ensuring better privacy for privileged events.
- Updated documentation to reflect the new cluster replication features and privacy considerations.
- Bumped version to v0.24.3 to reflect these changes.

app/main.go

@@ -164,7 +164,7 @@ func Run(
 	}
 
 	if len(clusterAdminNpubs) > 0 {
-		l.clusterManager = dsync.NewClusterManager(ctx, db, clusterAdminNpubs)
+		l.clusterManager = dsync.NewClusterManager(ctx, db, clusterAdminNpubs, cfg.ClusterPropagatePrivilegedEvents, l.publishers)
 		l.clusterManager.Start()
 		log.I.F("cluster replication manager initialized with %d admin npubs", len(clusterAdminNpubs))
 	}