Last life cycle refactor updates + add comprehensive documentation (#57)

Co-authored-by: Michal Pikulski <michal.a.pikulski@gmail.com>
Reviewed-on: #57

Assets/Scripts/Core/ItemManager.cs

@@ -47,8 +47,6 @@ namespace Core
         // Broadcasts when any two items are successfully combined
         // Args: first item data, second item data, result item data
         public event Action<PickupItemData, PickupItemData, PickupItemData> OnItemsCombined;
-
-        public override int ManagedAwakePriority => 75; // Item registry
         
         internal override void OnManagedAwake()
         {
@@ -67,10 +65,8 @@ namespace Core
             ClearAllRegistrations();
         }
         
-        protected override void OnDestroy()
+        internal override void OnManagedDestroy()
         {
-            base.OnDestroy();
-            
             // Ensure we clean up any subscriptions from registered items when the manager is destroyed
             ClearAllRegistrations();
         }