Add attribute system with core stats and gameplay components

GameCore/Combat/ProjectileComponent.cs

@@ -0,0 +1,13 @@
+using GameCore.Combat.Interfaces;
+using GameCore.ECS;
+using GameCore.ECS.Interfaces;
+
+namespace GameCore.Combat;
+
+public class ProjectileComponent : IComponent
+{
+    public Entity Owner { get; set; }
+    public float Lifetime { get; set; }
+
+    public List<IEffect> OnHitEffects { get; set; } = [];
+}