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/Editor/Tools/ItemPrefabEditor.cs

@@ -8,7 +8,7 @@ namespace Editor
     public class ItemPrefabEditorWindow : EditorWindow
     {
         private GameObject _selectedGameObject;
-        private Interactable _interactable;
+        private InteractableBase _interactable;
         private PickupItemData _pickupData;
         private PuzzleStepSO _objectiveData;
         private UnityEditor.Editor _soEditor;
@@ -42,17 +42,17 @@ namespace Editor
             if (Selection.activeGameObject != null)
             {
                 _selectedGameObject = Selection.activeGameObject;
-                _interactable = _selectedGameObject.GetComponent<Interactable>();
+                _interactable = _selectedGameObject.GetComponent<InteractableBase>();
             }
             else if (Selection.activeObject is GameObject go)
             {
                 _selectedGameObject = go;
-                _interactable = go.GetComponent<Interactable>();
+                _interactable = go.GetComponent<InteractableBase>();
             }
 
             if (_selectedGameObject == null || _interactable == null)
             {
-                EditorGUILayout.HelpBox("Select a GameObject or prefab with an Interactable component to edit.", MessageType.Info);
+                EditorGUILayout.HelpBox("Select a GameObject or prefab with an InteractableBase component to edit.", MessageType.Info);
                 return;
             }
 

Assets/Editor/Tools/PrefabCreatorWindow.cs

@@ -1,4 +1,4 @@
-using UnityEditor;
+using UnityEditor;
 using UnityEngine;
 using System.IO;
 using Interactions;
@@ -124,7 +124,7 @@ namespace Editor
         private void CreatePrefab()
         {
             var go = new GameObject(_prefabName);
-            go.AddComponent<Interactable>();
+            // Note: No need to add InteractableBase separately - Pickup and ItemSlot inherit from it
             go.AddComponent<BoxCollider>();
             int interactableLayer = LayerMask.NameToLayer("Interactable");
             if (interactableLayer != -1)