Refactor, cleanup code and add documentaiton

Assets/Scripts/CardSystem/StateMachine/CardStateMachine.cs

@@ -0,0 +1,19 @@
+using Core.SaveLoad;
+
+namespace UI.CardSystem.StateMachine
+{
+    /// <summary>
+    /// Card state machine that opts out of save system.
+    /// Cards are transient UI elements that don't need persistence.
+    /// </summary>
+    public class CardStateMachine : AppleMachine
+    {
+        /// <summary>
+        /// Opt out of save/load system - cards are transient and spawned from data.
+        /// </summary>
+        public override bool ShouldParticipateInSave()
+        {
+            return false;
+        }
+    }
+}