refactor: Consolidate skill component logic into SkillComponentBase and update manager access to singletons.

scripts/Resources/SkillData.cs

@@ -10,11 +10,10 @@ public partial class SkillData : Resource
     [Export] public string Name { get; set; } = "New Skill";
     [Export] public string Description { get; set; } = "New Skill";
     [Export] public Texture2D Icon { get; set; }
-    [Export] public bool IsActive { get; set; } = false;
     [Export] public int Level { get; set; } = 1;
     [Export] public SkillType Type { get; set; } = SkillType.Throw;
     [Export] public PackedScene Node { get; set; }
     [Export] public Array<SkillUpgrade> Upgrades { get; set; } = [];
-    
+
     public int MaxLevel => Upgrades.Count;
 }