Refactor and clean up codebase:

- Introduced `IGameRepository` interface and its implementation.
- Transitioned namespaces to `file-scoped` for consistency.
- Simplified class definitions, e.g., `Game` and `SixDigitInt`.
- Restructured `GameField` logic for improved readability and functionality.
- Fixed formatting issues in `API.csproj` and added a `using` directive in `Program.cs`.

API/Controllers/GameHubSocket.cs

@@ -4,18 +4,18 @@ namespace API.Controllers;
 
 public class GameHubSocket : Hub
 {
-    public async Task CreateGame(string playerName, )
+    public async Task CreateGame(string playerName)
     {
-        await Groups.AddToGroupAsync(Context.ConnectionId, gameId);
-        await Clients.Group(gameId).SendAsync("PlayerJoined", new
+        // TODO: create 
+        await Groups.AddToGroupAsync(Context.ConnectionId, "gameId");
+        await Clients.Group("gameId").SendAsync("PlayerJoined", new
         {
-            ConnectionId = Context.ConnectionId,
+            Context.ConnectionId,
             PlayerName = playerName
         });
     }
 
     public async Task JoinGame(string gameId, string playerName)
     {
-
     }
 }