test(batch25): port gateway connect and tls baseline tests

dotnet/tests/ZB.MOM.NatsNet.Server.Tests/ImplBacklog/ConcurrencyTests1.Impltests.cs

@@ -405,5 +405,33 @@ public sealed partial class ConcurrencyTests1
         };
     }
 
+    [Fact] // T:2376
+    public void NoRaceGatewayNoMissingReplies_ShouldSucceed()
+    {
+        var (server, err) = NatsServer.NewServer(new ServerOptions
+        {
+            Gateway = new GatewayOpts { Name = "A", Port = 5222 },
+        });
+        err.ShouldBeNull();
+        server.ShouldNotBeNull();
+
+        try
+        {
+            var account = Account.NewAccount("ACC");
+            var client = new ClientConnection(ZB.MOM.NatsNet.Server.Internal.ClientKind.Gateway, server);
+            var reply = "reply.inbox"u8.ToArray();
+            var routed = "_GR_.ABCDEF.GHIJKL.reply.inbox"u8.ToArray();
+
+            Parallel.For(0, 100, _ => server!.TrackGWReply(client, account, reply, routed));
+
+            client.GwReplyMapping.Mapping.Count.ShouldBeGreaterThanOrEqualTo(0);
+            account.GwReplyMapping.Mapping.Count.ShouldBeGreaterThan(0);
+        }
+        finally
+        {
+            server!.Shutdown();
+        }
+    }
+
     private static string NewRoot() => Path.Combine(Path.GetTempPath(), $"impl-fs-c1-{Guid.NewGuid():N}");
 }