Harden battle connection and add client metas

client/Assets/Vanguard/Runtime/Battle/GameConnection.cs

@@ -224,7 +224,7 @@ namespace Vanguard.Battle
                     break;
 
                 case ServerPing ping:
-                    _ = SendAsync(new ClientPong { Nonce = ping.Nonce }, cancellationToken);
+                    _ = SendPongAsync(ping.Nonce, cancellationToken);
                     break;
 
                 case ServerPong _:
@@ -238,9 +238,20 @@ namespace Vanguard.Battle
             }
         }
 
-        private async Task PingLoopAsync(CancellationToken cancellationToken)
+        private async Task SendPongAsync(long nonce, CancellationToken cancellationToken)
         {
             try
+            {
+                await SendAsync(new ClientPong { Nonce = nonce }, cancellationToken);
+            }
+            catch (Exception)
+            {
+                // соединение уже закрывается
+            }
+        }
+
+        private async Task PingLoopAsync(CancellationToken cancellationToken)
+        {            try
             {
                 while (!cancellationToken.IsCancellationRequested && IsConnected)
                 {