Merge ServiceLevel replay fixes for freshness integration

src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OpcUaApplicationHost.cs

@@ -560,10 +560,15 @@ public sealed class OpcUaApplicationHost : IAsyncDisposable
     /// <returns>A task that represents the asynchronous operation.</returns>
     public async ValueTask DisposeAsync()
     {
-        if (_impersonateHandler is not null && _server?.CurrentInstance?.SessionManager is { } sessionManager)
+        try
         {
-            try { sessionManager.ImpersonateUser -= _impersonateHandler; }
-            catch (Exception ex) { _logger.LogWarning(ex, "OpcUaApplicationHost: detaching ImpersonateUser threw"); }
+            // An explicit SDK stop may already have halted CurrentInstance; still continue disposal.
+            if (_impersonateHandler is not null && _server?.CurrentInstance?.SessionManager is { } sessionManager)
+                sessionManager.ImpersonateUser -= _impersonateHandler;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "OpcUaApplicationHost: detaching ImpersonateUser threw");
         }
         _impersonateHandler = null;
 

src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/SdkServiceLevelPublisher.cs

@@ -38,8 +38,8 @@ public sealed class SdkServiceLevelPublisher : IServiceLevelPublisher
         var node = _serverInternal.ServerObject?.ServiceLevel;
         if (node is null)
         {
-            _logger.LogWarning("SdkServiceLevelPublisher: ServerObject.ServiceLevel unavailable; skipping write");
-            return;
+            _logger.LogWarning("SdkServiceLevelPublisher: ServerObject.ServiceLevel unavailable");
+            throw new InvalidOperationException("Server.ServiceLevel is unavailable.");
         }
 
         try
@@ -55,6 +55,7 @@ public sealed class SdkServiceLevelPublisher : IServiceLevelPublisher
         catch (Exception ex)
         {
             _logger.LogWarning(ex, "SdkServiceLevelPublisher: write to Server.ServiceLevel threw");
+            throw;
         }
     }
 }