[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/ShopCatalog.cs

@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+[CreateAssetMenu(fileName = "ShopCatalog", menuName = "YachtDice/Shop Catalog")]
+public sealed class ShopCatalog : ScriptableObject
+{
+    [SerializeField] private List<ModifierData> availableModifiers = new();
+
+    public IReadOnlyList<ModifierData> AvailableModifiers => availableModifiers;
+
+    public ModifierData FindById(string id)
+    {
+        for (int i = 0; i < availableModifiers.Count; i++)
+        {
+            if (availableModifiers[i] != null && availableModifiers[i].Id == id)
+                return availableModifiers[i];
+        }
+        return null;
+    }
+}

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);
+    }
+}

Assets/Scripts/Shop/ShopItemView.cs

@@ -0,0 +1,87 @@
+using System;
+using TMPro;
+using UnityEngine;
+using UnityEngine.UI;
+
+public sealed class ShopItemView : MonoBehaviour
+{
+    [SerializeField] private Image iconImage;
+    [SerializeField] private TMP_Text nameText;
+    [SerializeField] private TMP_Text descriptionText;
+    [SerializeField] private TMP_Text priceText;
+    [SerializeField] private TMP_Text rarityText;
+    [SerializeField] private Button buyButton;
+    [SerializeField] private TMP_Text buyButtonText;
+    [SerializeField] private Image background;
+
+    [Header("Rarity Colors")]
+    [SerializeField] private Color commonColor = Color.white;
+    [SerializeField] private Color uncommonColor = new(0.4f, 0.8f, 0.4f);
+    [SerializeField] private Color rareColor = new(0.4f, 0.6f, 1f);
+    [SerializeField] private Color epicColor = new(0.8f, 0.4f, 1f);
+
+    private ModifierData data;
+
+    public event Action<ModifierData> OnBuyClicked;
+
+    private void Awake()
+    {
+        if (buyButton != null)
+            buyButton.onClick.AddListener(() => OnBuyClicked?.Invoke(data));
+    }
+
+    public void Setup(ModifierData modifierData, ShopItemState state)
+    {
+        data = modifierData;
+
+        if (nameText != null) nameText.text = data.DisplayName;
+        if (descriptionText != null) descriptionText.text = data.Description;
+        if (priceText != null) priceText.text = data.ShopPrice.ToString();
+        if (iconImage != null && data.Icon != null) iconImage.sprite = data.Icon;
+
+        if (rarityText != null)
+        {
+            rarityText.text = data.Rarity.ToString();
+            rarityText.color = GetRarityColor(data.Rarity);
+        }
+
+        SetState(state);
+    }
+
+    public void SetState(ShopItemState state)
+    {
+        if (buyButton == null) return;
+
+        switch (state)
+        {
+            case ShopItemState.Available:
+                buyButton.interactable = true;
+                if (buyButtonText != null) buyButtonText.text = "Buy";
+                break;
+            case ShopItemState.RepurchaseAvailable:
+                buyButton.interactable = true;
+                if (buyButtonText != null) buyButtonText.text = "Buy";
+                break;
+            case ShopItemState.TooExpensive:
+                buyButton.interactable = false;
+                if (buyButtonText != null) buyButtonText.text = "Buy";
+                break;
+            case ShopItemState.Owned:
+                buyButton.interactable = false;
+                if (buyButtonText != null) buyButtonText.text = "Owned";
+                break;
+        }
+    }
+
+    private Color GetRarityColor(ModifierRarity rarity)
+    {
+        return rarity switch
+        {
+            ModifierRarity.Common => commonColor,
+            ModifierRarity.Uncommon => uncommonColor,
+            ModifierRarity.Rare => rareColor,
+            ModifierRarity.Epic => epicColor,
+            _ => commonColor
+        };
+    }
+}

Assets/Scripts/Shop/ShopModel.cs

@@ -0,0 +1,78 @@
+using System;
+using System.Collections.Generic;
+
+public sealed class ShopModel
+{
+    private readonly CurrencyBank currencyBank;
+    private readonly InventoryModel inventoryModel;
+    private readonly HashSet<string> purchasedPermanentIds = new();
+
+    public event Action<ModifierData> OnItemPurchased;
+
+    public ShopModel(CurrencyBank currencyBank, InventoryModel inventoryModel)
+    {
+        this.currencyBank = currencyBank;
+        this.inventoryModel = inventoryModel;
+    }
+
+    public bool CanPurchase(ModifierData modifier)
+    {
+        if (modifier == null) return false;
+        if (!currencyBank.CanAfford(modifier.ShopPrice)) return false;
+
+        if (modifier.Durability == ModifierDurability.Permanent &&
+            purchasedPermanentIds.Contains(modifier.Id))
+            return false;
+
+        return true;
+    }
+
+    public bool TryPurchase(ModifierData modifier)
+    {
+        if (!CanPurchase(modifier)) return false;
+
+        if (!currencyBank.Spend(modifier.ShopPrice)) return false;
+
+        if (modifier.Durability == ModifierDurability.Permanent)
+            purchasedPermanentIds.Add(modifier.Id);
+
+        inventoryModel.AddModifier(modifier);
+        OnItemPurchased?.Invoke(modifier);
+        return true;
+    }
+
+    public bool IsPermanentOwned(string modifierId) => purchasedPermanentIds.Contains(modifierId);
+
+    public ShopItemState GetItemState(ModifierData modifier)
+    {
+        if (modifier == null) return ShopItemState.TooExpensive;
+
+        if (modifier.Durability == ModifierDurability.Permanent &&
+            purchasedPermanentIds.Contains(modifier.Id))
+            return ShopItemState.Owned;
+
+        if (!currencyBank.CanAfford(modifier.ShopPrice))
+            return ShopItemState.TooExpensive;
+
+        return modifier.Durability == ModifierDurability.LimitedUses
+            ? ShopItemState.RepurchaseAvailable
+            : ShopItemState.Available;
+    }
+
+    public void LoadPurchasedPermanentIds(IEnumerable<string> ids)
+    {
+        purchasedPermanentIds.Clear();
+        if (ids != null)
+            foreach (var id in ids) purchasedPermanentIds.Add(id);
+    }
+
+    public HashSet<string> GetPurchasedPermanentIds() => new(purchasedPermanentIds);
+}
+
+public enum ShopItemState
+{
+    Available,
+    TooExpensive,
+    Owned,
+    RepurchaseAvailable
+}

Assets/Scripts/Shop/ShopView.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using TMPro;
+using UnityEngine;
+using UnityEngine.UI;
+
+public sealed class ShopView : MonoBehaviour
+{
+    [SerializeField] private Transform itemContainer;
+    [SerializeField] private ShopItemView itemPrefab;
+    [SerializeField] private TMP_Text currencyText;
+    [SerializeField] private Button closeButton;
+
+    private readonly List<ShopItemView> spawnedItems = new();
+
+    public event Action<ModifierData> OnBuyClicked;
+
+    private void Awake()
+    {
+        if (closeButton != null)
+            closeButton.onClick.AddListener(Hide);
+    }
+
+    private void OnDestroy()
+    {
+        if (closeButton != null)
+            closeButton.onClick.RemoveListener(Hide);
+    }
+
+    public void Show() => gameObject.SetActive(true);
+    public void Hide() => gameObject.SetActive(false);
+    public bool IsVisible => gameObject.activeSelf;
+
+    public void Populate(IReadOnlyList<ModifierData> catalog, ShopModel model)
+    {
+        ClearItems();
+
+        for (int i = 0; i < catalog.Count; i++)
+        {
+            var data = catalog[i];
+            if (data == null) continue;
+
+            var item = Instantiate(itemPrefab, itemContainer);
+            var state = model.GetItemState(data);
+            item.Setup(data, state);
+            item.OnBuyClicked += HandleBuy;
+            spawnedItems.Add(item);
+        }
+    }
+
+    public void RefreshStates(IReadOnlyList<ModifierData> catalog, ShopModel model)
+    {
+        for (int i = 0; i < spawnedItems.Count && i < catalog.Count; i++)
+        {
+            var state = model.GetItemState(catalog[i]);
+            spawnedItems[i].SetState(state);
+        }
+    }
+
+    public void UpdateCurrencyDisplay(int currency)
+    {
+        if (currencyText != null)
+            currencyText.text = currency.ToString();
+    }
+
+    private void ClearItems()
+    {
+        for (int i = 0; i < spawnedItems.Count; i++)
+        {
+            spawnedItems[i].OnBuyClicked -= HandleBuy;
+            Destroy(spawnedItems[i].gameObject);
+        }
+        spawnedItems.Clear();
+    }
+
+    private void HandleBuy(ModifierData data) => OnBuyClicked?.Invoke(data);
+}