fix(communication): generation-suffixed, sanitized ClusterClient actor names to prevent recreate name collision

src/ZB.MOM.WW.ScadaBridge.Communication/Actors/CentralCommunicationActor.cs

@@ -32,11 +32,35 @@ public interface ISiteClientFactory
 /// </summary>
 public class DefaultSiteClientFactory : ISiteClientFactory
 {
+    /// <summary>
+    /// Per-incarnation generation counter. Context.Stop of the previous client is
+    /// asynchronous — its actor name stays reserved until termination completes —
+    /// so a same-named recreate in the same message handling throws
+    /// InvalidActorNameException. A generation suffix makes every incarnation's
+    /// name unique by construction (mirrors SiteStreamGrpcServer._actorCounter).
+    /// </summary>
+    private long _generation;
+
     /// <inheritdoc />
     public IActorRef Create(ActorSystem system, string siteId, ImmutableHashSet<ActorPath> contacts)
     {
         var settings = ClusterClientSettings.Create(system).WithInitialContacts(contacts);
-        return system.ActorOf(ClusterClient.Props(settings), $"site-client-{siteId}");
+        var name = $"site-client-{SanitizeForActorName(siteId)}-{System.Threading.Interlocked.Increment(ref _generation)}";
+        return system.ActorOf(ClusterClient.Props(settings), name);
+    }
+
+    /// <summary>
+    /// Maps an arbitrary SiteIdentifier onto a valid Akka actor-path element:
+    /// letters/digits/'-'/'_' pass through, everything else becomes '_'. Uniqueness
+    /// is NOT required here (the generation suffix guarantees it); only validity is.
+    /// </summary>
+    internal static string SanitizeForActorName(string siteId)
+    {
+        if (string.IsNullOrEmpty(siteId)) return "site";
+        var sanitized = new string(siteId
+            .Select(c => char.IsAsciiLetterOrDigit(c) || c is '-' or '_' ? c : '_')
+            .ToArray());
+        return ActorPath.IsValidPathElement(sanitized) ? sanitized : "site";
     }
 }