Overhaul game state logic to support gameplay loop

Zennysoft.Game.Ma/src/ui/player_ui/PlayerInfoUI.cs

@@ -9,6 +9,8 @@ namespace Zennysoft.Game.Ma;
 public interface IPlayerInfoUI : IControl
 {
   public void DisplayMessage(string message);
+
+  public void Activate();
 }
 
 [Meta(typeof(IAutoNode))]
@@ -33,6 +35,10 @@ public partial class PlayerInfoUI : Control, IPlayerInfoUI
   public void OnResolved()
   {
     _labelSettings = GD.Load<LabelSettings>("res://src/ui/label_settings/InventoryFullAlertLabelSetting.tres");
+  }
+
+  public void Activate()
+  {
     Player.Stats.CurrentHP.Sync += CurrentHP_Sync;
     Player.Stats.MaximumHP.Sync += MaximumHP_Sync;