Debug signalr

Shogi.UI/Shared/GameHubNode.cs

@@ -23,6 +23,19 @@ public class GameHubNode : IAsyncDisposable
 				options.Transports = Microsoft.AspNetCore.Http.Connections.HttpTransportType.WebSockets;
 			})
 		.Build();
+
+		this.hubConnection.Closed += this.HubConnection_Closed;
+	}
+
+	private Task HubConnection_Closed(Exception? arg)
+	{
+		Console.WriteLine("SignalR connection closed");
+		if (arg != null)
+		{
+			Console.WriteLine("Because {0}", arg.Message);
+		}
+
+		return Task.CompletedTask;
 	}
 
 	public bool IsConnected => this.hubConnection.State == HubConnectionState.Connected;