Refactoring of the interaction system and preliminary integration of save/load functionality across the game. (#44)

### Interactables Architecture Refactor
- Converted composition to inheritance, moved from component-based to class-based interactables. No more requirement for chain of "Interactable -> Item" etc.
- Created `InteractableBase` abstract base class with common functionality that replaces the old component
- Specialized child classes: `Pickup`, `ItemSlot`, `LevelSwitch`, `MinigameSwitch`, `CombinationItem`, `OneClickInteraction` are now children classes
- Light updates to the interactable inspector, moved some things arround, added collapsible inspector sections in the  UI for better editor experience

### State Machine Integration
- Custom `AppleMachine` inheritong from Pixelplacement's StateMachine which implements our own interface for saving, easy place for future improvements
- Replaced all previous StateMachines by `AppleMachine`
- Custom `AppleState`  extends from default `State`. Added serialization, split state logic into "EnterState", "RestoreState", "ExitState" allowing for separate logic when triggering in-game vs loading game
- Restores directly to target state without triggering transitional logic
- Migration tool converts existing instances

### Prefab Organization
- Saved changes from scenes into prefabs
- Cleaned up duplicated components, confusing prefabs hierarchies
- Created prefab variants where possible
- Consolidated Environment prefabs and moved them out of Placeholders subfolder into main Environment folder
- Organized item prefabs from PrefabsPLACEHOLDER into proper Items folder
- Updated prefab references - All scene references updated to new locations
- Removed placeholder files from Characters, Levels, UI, and Minigames folders

### Scene Updates
- Quarry scene with major updates
- Saved multiple working versions (Quarry, Quarry_Fixed, Quarry_OLD)
- Added proper lighting data
- Updated all interactable components to new architecture

### Minor editor tools
- New tool for testing cards from an editor window (no in-scene object required)
- Updated Interactable Inspector
- New debug option to opt in-and-out of the save/load system
- Tooling for easier migration

Co-authored-by: Michal Pikulski <michal.a.pikulski@gmail.com>
Reviewed-on: #44

Assets/Scripts/Interactions/Interactable.cs

@@ -17,9 +17,10 @@ namespace Interactions
     }
     
     /// <summary>
-    /// Represents an interactable object that can respond to tap input events.
+    /// Base class for interactable objects that can respond to tap input events.
+    /// Subclasses should override OnCharacterArrived() to implement interaction-specific logic.
     /// </summary>
-    public class Interactable : MonoBehaviour, ITouchInputConsumer
+    public class InteractableBase : MonoBehaviour, ITouchInputConsumer
     {
         [Header("Interaction Settings")]
         public bool isOneTime;
@@ -34,8 +35,8 @@ namespace Interactions
         
         // Helpers for managing interaction state
         private bool _interactionInProgress;
-        private PlayerTouchController _playerRef;
-        private FollowerController _followerController;
+        protected PlayerTouchController _playerRef;
+        protected FollowerController _followerController;
         private bool _isActive = true;
         private InteractionEventType _currentEventType;
         
@@ -420,7 +421,7 @@ namespace Interactions
             if (step != null && !step.IsStepUnlocked() && slot == null)
             {
                 DebugUIMessage.Show("This step is locked!", Color.yellow);
-                BroadcastInteractionComplete(false);
+                CompleteInteraction(false);
                 // Reset variables for next time
                 _interactionInProgress = false;
                 _playerRef = null;
@@ -434,6 +435,9 @@ namespace Interactions
             // Broadcast appropriate event
             characterArrived?.Invoke();
             
+            // Call the virtual method for subclasses to override
+            OnCharacterArrived();
+            
             // Reset variables for next time
             _interactionInProgress = false;
             _playerRef = null;
@@ -441,6 +445,17 @@ namespace Interactions
             return Task.CompletedTask;
         }
         
+        /// <summary>
+        /// Called when the character has arrived at the interaction point.
+        /// Subclasses should override this to implement interaction-specific logic
+        /// and call CompleteInteraction(bool success) when done.
+        /// </summary>
+        protected virtual void OnCharacterArrived()
+        {
+            // Default implementation does nothing - subclasses should override
+            // and call CompleteInteraction when their logic is complete
+        }
+        
         private async void OnInteractionComplete(bool success)
         {
             // Dispatch InteractionComplete event
@@ -481,11 +496,25 @@ namespace Interactions
             throw new NotImplementedException();
         }
 
-        public void BroadcastInteractionComplete(bool success)
+        /// <summary>
+        /// Call this from subclasses to mark the interaction as complete.
+        /// </summary>
+        /// <param name="success">Whether the interaction was successful</param>
+        protected void CompleteInteraction(bool success)
         {
             interactionComplete?.Invoke(success);
         }
         
+        /// <summary>
+        /// Legacy method for backward compatibility. Use CompleteInteraction instead.
+        /// </summary>
+        /// TODO: Remove this method in future versions
+        [Obsolete("Use CompleteInteraction instead")]
+        public void BroadcastInteractionComplete(bool success)
+        {
+            CompleteInteraction(success);
+        }
+        
     #if UNITY_EDITOR
         /// <summary>
         /// Draws gizmos for pickup interaction range in the editor.