doc: Clarify async updates are supported but clusterin isn't (#5359)

Author: mshabarov

articles/flow/ui-state/shared-signals.adoc

@@ -205,22 +205,24 @@ Signal.effect(component, () -> {
 ----
 
 
-=== Getting Cluster-Confirmed Values
+=== Getting Confirmed Values Asynchronously
 
-The `peekConfirmed()` method returns the last value that has been confirmed by the cluster. This is useful in distributed scenarios where you need to know the definitive server-confirmed state:
+The `peekConfirmed()` method returns the last value that has been asynchronously confirmed. This is useful in distributed scenarios where you need to know the definitive server-confirmed state:
 
 [source,java]
 ----
 SharedValueSignal<String> signal = new SharedValueSignal<>(String.class);
 
-// Get the locally-known value (may include optimistic updates)
+// Get the locally known value (may include optimistic updates)
 String optimistic = signal.peek();
 
-// Get only the cluster-confirmed value
+// Get only the asynchronously confirmed value
 String confirmed = signal.peekConfirmed();
 ----
 
-In single-server deployments, `peekConfirmed()` typically returns the same value as `peek()`. In clustered environments, there may be a brief delay between optimistic local updates and cluster confirmation.
+Shared signals currently support asynchronously confirmed updates only in single JVM environments but don't yet provide an  implementation for asynchronous updates and confirmations in a cluster environment.
+
+In single JVM deployments, `peekConfirmed()` typically returns the same value as `peek()`. In clustered environments, there may be a brief delay between optimistic local updates and cluster confirmation.
 
 
 == Writing Values