Add MainMenu and Marketplace components; implement game management and skill unlocking features

scripts/UI/MainMenu.cs

@@ -0,0 +1,67 @@
+using Godot;
+using Mr.BrickAdventures.Autoloads;
+
+namespace Mr.BrickAdventures.scripts.UI;
+
+public partial class MainMenu : Node
+{
+    [Export] public Control MainMenuControl { get; set; }
+    [Export] public Button NewGameButton { get; set; }
+    [Export] public Button ContinueButton { get; set; }
+    [Export] public Button SettingsButton { get; set; }
+    [Export] public Button CreditsButton { get; set; }
+    [Export] public Button ExitButton { get; set; }
+    [Export] public Label VersionLabel { get; set; }
+    [Export] public Control SettingsControl { get; set; }
+    [Export] public Control CreditsControl { get; set; }
+    
+    private SaveSystem _saveSystem;
+    private GameManager _gameManager;
+    private UIManager _uiManager;
+
+    public override void _Ready()
+    {
+        _saveSystem = GetNode<SaveSystem>("/root/SaveSystem");
+        _gameManager = GetNode<GameManager>("/root/GameManager");
+        _uiManager = GetNode<UIManager>("/root/UIManager");
+
+        NewGameButton.Pressed += OnNewGamePressed;
+        ContinueButton.Pressed += OnContinuePressed;
+        SettingsButton.Pressed += OnSettingsPressed;
+        CreditsButton.Pressed += OnCreditsPressed;
+        ExitButton.Pressed += OnExitPressed;
+
+        VersionLabel.Text = $"v. {ProjectSettings.GetSetting("application/config/version")}";
+        ContinueButton.Disabled = !_saveSystem.CheckSaveExists();
+
+        if (_saveSystem.CheckSaveExists())
+            ContinueButton.GrabFocus();
+        else
+            NewGameButton.GrabFocus();
+    }
+
+    private void OnExitPressed()
+    {
+        _gameManager.QuitGame();
+    }
+
+    private void OnCreditsPressed()
+    {
+        _uiManager.PushScreen(CreditsControl);
+    }
+
+    private void OnSettingsPressed()
+    {
+        _uiManager.PushScreen(SettingsControl);
+    }
+
+    private void OnContinuePressed()
+    {
+        _gameManager.ContinueGame();
+    }
+
+    private void OnNewGamePressed()
+    {
+        _gameManager.StartNewGame();
+    }
+}