Replace custom socket implementation with SignalR.

Replace MSAL and custom cookie auth with Microsoft.Identity.EntityFramework
Also some UI redesign to accommodate different login experience.

Shogi.UI/Pages/Play/PlayPage.razor

@@ -0,0 +1,28 @@
+@attribute [Authorize]
+@page "/play/{sessionId}"
+
+@inject GameHubNode node
+
+@if (string.IsNullOrWhiteSpace(SessionId))
+{
+	return;
+}
+<main class="PrimaryTheme">
+	<AuthorizeView>
+		<GameBoard SessionId="@SessionId" />
+	</AuthorizeView>
+</main>
+
+@code {
+
+	[Parameter]
+	public string? SessionId { get; set; }
+
+	protected override async Task OnParametersSetAsync()
+	{
+		if (!node.IsConnected)
+		{
+			await node.BeginListen();
+		}
+	}
+}