Rework shop to support multiple item types and add unified PlayerModel

Generalize the shop from selling only ModifierDefinition to any IShopItem
(modifiers + dice). Add purchase condition checks, hover tooltips, and
fixed prices. Introduce PlayerModel as a facade over CurrencyBank,
InventoryModel, and DiceCollection for centralized state and save/load.

New files:
- IShopItem interface for purchasable items
- ShopCatalog SO (unified catalog for all item types)
- ShopTooltipView (description on hover)
- PlayerModel (aggregates player state)
- DiceCollection (owned dice tracking)
- DiceCatalog SO (dice definition registry)
- DiceCollectionTests

Modified:
- ModifierDefinition/DieDefinitionSO implement IShopItem
- ShopModel/ShopView/ShopItemView/ShopController use IShopItem
- SaveData v3 with OwnedDiceIds
- GameController uses PlayerModel for save/load
- GameLifetimeScope registers new services

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

Assets/Scripts/Dice/DiceCatalog.cs

@@ -0,0 +1,32 @@
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace YachtDice.Dice
+{
+    [CreateAssetMenu(fileName = "DiceCatalog", menuName = "YachtDice/Dice/Catalog")]
+    public class DiceCatalog : ScriptableObject
+    {
+        [SerializeField] private List<DieDefinitionSO> dice = new();
+
+        public IReadOnlyList<DieDefinitionSO> All => dice;
+
+        public DieDefinitionSO FindById(string id)
+        {
+            for (int i = 0; i < dice.Count; i++)
+            {
+                if (dice[i] != null && dice[i].Id == id)
+                    return dice[i];
+            }
+            return null;
+        }
+
+#if UNITY_EDITOR
+        public static DiceCatalog CreateForTest(List<DieDefinitionSO> defs)
+        {
+            var catalog = CreateInstance<DiceCatalog>();
+            catalog.dice = defs ?? new List<DieDefinitionSO>();
+            return catalog;
+        }
+#endif
+    }
+}