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/PuzzleS/ObjectiveStepBehaviour.cs

@@ -8,7 +8,7 @@ namespace PuzzleS
     /// <summary>
     /// Manages the state and interactions for a single puzzle step, including unlock/lock logic and event handling.
     /// </summary>
-    [RequireComponent(typeof(Interactable))]
+    [RequireComponent(typeof(InteractableBase))]
     public class ObjectiveStepBehaviour : MonoBehaviour, IPuzzlePrompt
     {
         /// <summary>
@@ -20,7 +20,7 @@ namespace PuzzleS
         [SerializeField] private GameObject puzzleIndicator;
         [SerializeField] private bool drawPromptRangeGizmo = true;
 
-        private Interactable _interactable;
+        private InteractableBase _interactable;
         private bool _isUnlocked = false;
         private bool _isCompleted = false;
         private IPuzzlePrompt _indicator;
@@ -33,7 +33,7 @@ namespace PuzzleS
 
         void Awake()
         {
-            _interactable = GetComponent<Interactable>();
+            _interactable = GetComponent<InteractableBase>();
             
             // Initialize the indicator if it exists, but ensure it's hidden initially
             if (puzzleIndicator != null)
@@ -60,7 +60,7 @@ namespace PuzzleS
         void OnEnable()
         {
             if (_interactable == null)
-                _interactable = GetComponent<Interactable>();
+                _interactable = GetComponent<InteractableBase>();
             
             if (_interactable != null)
             {