fix: session B — Go-faithful auth error states, NKey padding, permissions, signal disposal

dotnet/src/ZB.MOM.NatsNet.Server/NatsServer.Signals.cs

@@ -73,7 +73,7 @@ public sealed partial class NatsServer
         });
     }
 
-    private void DisposeSignalHandlers()
+    internal void DisposeSignalHandlers()
     {
         _sigHup?.Dispose();
         _sigTerm?.Dispose();