add game completion handling and menu navigation

Code/Systems/GameManager.cs

@@ -13,7 +13,9 @@ public partial class GameManager : Node
     
     [Export] private Control _winScreen;
     [Export] private Control _loseScreen;
+    [Export] private Control _gameCompleteScreen;
     [Export] private Label _dayLabel;
+    [Export] private PackedScene _mainMenuScene;
     
     private int _currentDayIndex = 0;
     private Node _currentMiniGame;
@@ -21,7 +23,7 @@ public partial class GameManager : Node
     public override void _Ready()
     {
         EventBus.OnLiftCompleted += HandleLiftResult;
-        StartDay(_currentDayIndex);
+        CallDeferred(nameof(StartDay), _currentDayIndex);
     }
 
     public override void _ExitTree()
@@ -34,7 +36,16 @@ public partial class GameManager : Node
         if (index >= _days.Count)
         {
             GD.Print("YOU BEAT THE GYM! ALL DAYS COMPLETE.");
-            // TODO: Show "Game Complete" screen
+            _currentMiniGame?.QueueFree();
+            _hazardSystem.ClearHazards();
+        
+            if (_winScreen != null) _winScreen.Visible = false;
+            if (_loseScreen != null) _loseScreen.Visible = false;
+        
+            if (_gameCompleteScreen != null) 
+            {
+                _gameCompleteScreen.Visible = true;
+            }
             return;
         }
 
@@ -68,18 +79,33 @@ public partial class GameManager : Node
         {
             GD.Print("Day Complete! Next day loading...");
             if (_winScreen != null) _winScreen.Visible = true;
-            
-            // Wait for player input to proceed, or auto-load after delay
-            // For now, let's auto-advance after 3 seconds for the prototype
-            GetTree().CreateTimer(3.0f).Timeout += () => NextDay();
         }
         else
         {
             GD.Print("FAIL! Go home.");
             if (_loseScreen != null) _loseScreen.Visible = true;
-            
-            // Restart day after delay
-            GetTree().CreateTimer(3.0f).Timeout += () => RestartDay();
+        }
+    }
+    
+    public void OnNextDayPressed()
+    {
+        NextDay();
+    }
+
+    public void OnRetryPressed()
+    {
+        RestartDay();
+    }
+
+    public void OnMenuPressed()
+    {
+        if (_mainMenuScene != null)
+        {
+            GetTree().ChangeSceneToPacked(_mainMenuScene);
+        }
+        else
+        {
+            GetTree().Quit(); 
         }
     }