[Add] Universal modifier system, shop, inventory & persistence

Replace hardcoded BonusForOnes/MultiplierForSixes with data-driven
modifier system supporting 2 scopes (SelectedCategory, AnyCategoryClosed),
4 effect types, durability modes (Permanent, LimitedUses), and
configurable targets via ScriptableObject (ModifierData).

- Modifier domain: ModifierEnums, ModifierTarget, ModifierData,
  ModifierRuntime, ModifierEffect (dict-based strategy), ModifierPipeline
  (4-pass: cat-additive → cat-multiplicative → final-additive → final-multiplicative)
- ScoringSystem: replaced old modifier list with ModifierPipeline integration,
  added OnCategoryConfirmed event
- Shop MVC: ShopCatalog (SO), ShopModel, ShopView, ShopItemView, ShopController
- Inventory MVC: InventoryModel (activate/deactivate/sell/durability),
  InventoryView, InventorySlotView, InventoryController
- CurrencyBank: editor-adjustable balance with events
- Persistence: SaveData + SaveSystem (Newtonsoft JSON + PlayerPrefs)
- Editor: ModifierAssetCreator menu item to generate 6 example modifiers + catalog
- Tests: 6 test classes covering effects, pipeline, scoring, shop, inventory, save
- GameController: wired shop/inventory/save lifecycle
- GameInfoView: added currency display, shop/inventory toggle buttons

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Assets/Scripts/Shop/ShopController.cs

@@ -0,0 +1,55 @@
+using UnityEngine;
+
+public sealed class ShopController : MonoBehaviour
+{
+    [SerializeField] private ShopCatalog catalog;
+    [SerializeField] private ShopView shopView;
+    [SerializeField] private CurrencyBank currencyBank;
+
+    private ShopModel model;
+
+    public ShopCatalog Catalog => catalog;
+
+    public void Initialize(ShopModel shopModel)
+    {
+        model = shopModel;
+
+        shopView.OnBuyClicked += HandleBuyClicked;
+
+        if (currencyBank != null)
+            currencyBank.OnBalanceChanged += HandleCurrencyChanged;
+
+        model.OnItemPurchased += HandleItemPurchased;
+
+        shopView.Populate(catalog.AvailableModifiers, model);
+        shopView.UpdateCurrencyDisplay(currencyBank != null ? currencyBank.Balance : 0);
+    }
+
+    private void OnDestroy()
+    {
+        if (shopView != null)
+            shopView.OnBuyClicked -= HandleBuyClicked;
+
+        if (currencyBank != null)
+            currencyBank.OnBalanceChanged -= HandleCurrencyChanged;
+
+        if (model != null)
+            model.OnItemPurchased -= HandleItemPurchased;
+    }
+
+    private void HandleBuyClicked(ModifierData data)
+    {
+        model.TryPurchase(data);
+    }
+
+    private void HandleCurrencyChanged(int newBalance)
+    {
+        shopView.UpdateCurrencyDisplay(newBalance);
+        shopView.RefreshStates(catalog.AvailableModifiers, model);
+    }
+
+    private void HandleItemPurchased(ModifierData data)
+    {
+        shopView.RefreshStates(catalog.AvailableModifiers, model);
+    }
+}