Revert "Create db and db access. Add json converter for board array. Add tests for json conversion"

This reverts commit 7a532e52e1.

JoshHeaps.Net/Models/GameState.cs

@@ -1,8 +1,4 @@
 using JoshHeaps.Net.Services.Implementations;
-using JoshHeaps.Net.Utilities;
-using Microsoft.EntityFrameworkCore.Storage.ValueConversion.Internal;
-using System.ComponentModel.DataAnnotations.Schema;
-using System.Text.Json.Serialization;
 
 namespace JoshHeaps.Net.Models;
 
@@ -12,7 +8,6 @@ public class GameState
 
     // 8x8 board of references. Null if no piece is present.
     // row 0 at top -> row 7 at bottom (typical 0-based array).
-    [JsonConverter(typeof(ChessBoardConverter))]
     public ChessPiece?[,] Board { get; set; }
 
     // Whose turn is it?
@@ -47,10 +42,7 @@ public class GameState
     public Guid BlackPlayerId { get; set; }
 
     public bool IsVsComputer { get; set; } = false;
-    public int ComputerDifficulty { get; set; } = 20;
 
-    [JsonIgnore]          // <-- exclude from JSON
-    [NotMapped]           // <-- EF won't try to persist it either
     public Stockfish? Computer { get; set; }
 
     // optional: convenience