fix(mesh): memoize dialer/provider on first use — a lost PreStart race self-heals at the first refresh (review-prescribed)

src/Server/ZB.MOM.WW.OtOpcUa.ControlPlane/Communication/CentralCommunicationActor.cs

@@ -73,6 +73,18 @@ public sealed class CentralCommunicationActor : ReceiveActor, IWithTimers
     private IMeshCommandDialer? _dialer;
     private IMeshPskProvider? _pskProvider;
 
+    // Memoize-on-first-use, NOT PreStart-only: PreStart runs on a dispatcher thread concurrently
+    // with the builder's remaining starters, so its resolve can lose a millisecond-wide race
+    // against AuditWriterActorKey's registration (starter #4) and Resolve() would swallow that
+    // into a PERMANENT silent null — the known-cluster gate never published, fail-open. These
+    // properties retry on first use instead; the first RefreshContacts arrives as a message,
+    // long after every starter finished, so a lost boot race self-heals there. Actor-thread
+    // only, so ??= needs no synchronisation; both are container singletons, so a repeat resolve
+    // is a dictionary hit.
+    private IMeshPskProvider? PskProvider => _pskProvider ??= Resolve(_pskProviderFactory, nameof(IMeshPskProvider));
+
+    private IMeshCommandDialer? Dialer => _dialer ??= Resolve(_dialerFactory, nameof(IMeshCommandDialer));
+
     private readonly ILoggingAdapter _log = Context.GetLogger();
     private readonly bool _useClusterClient;
     private readonly bool _useGrpc;
@@ -382,7 +394,7 @@ public sealed class CentralCommunicationActor : ReceiveActor, IWithTimers
     {
         var commandType = cmd.Message.GetType().Name;
 
-        var dialer = _dialer;
+        var dialer = Dialer;
         if (dialer is null)
         {
             _log.Error(
@@ -796,8 +808,8 @@ public sealed class CentralCommunicationActor : ReceiveActor, IWithTimers
     /// </remarks>
     private void PublishKnownClusters(ContactsLoaded msg)
     {
-        _pskProvider?.SetKnownClusters(msg.ClusterIds);
-        _pskProvider?.InvalidateAll();
+        PskProvider?.SetKnownClusters(msg.ClusterIds);
+        PskProvider?.InvalidateAll();
     }
 
     /// <summary>Stops a cluster's existing client and creates a replacement for its new contact set.</summary>