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.Api/Controllers/Extentions.cs

@@ -0,0 +1,11 @@
+using System.Security.Claims;
+
+namespace Shogi.Api.Controllers;
+
+public static class Extentions
+{
+	public static string? GetId(this ClaimsPrincipal self)
+	{
+		return self.Claims.FirstOrDefault(claim => claim.Type == ClaimTypes.NameIdentifier)?.Value;
+	}
+}