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/Tests/Editor/ShopModelTests.cs

@@ -1,7 +1,9 @@
 using NUnit.Framework;
 using UnityEngine;
+using YachtDice.Dice;
 using YachtDice.Economy;
 using YachtDice.Inventory;
+using YachtDice.Player;
 using YachtDice.Shop;
 using YachtDice.Modifiers.Definition;
 using YachtDice.Modifiers.Runtime;
@@ -13,6 +15,7 @@ namespace YachtDice.Tests
         private CurrencyBank bank;
         private ModifierRegistry registry;
         private InventoryModel inventory;
+        private DiceCollection diceCollection;
         private ShopModel shop;
 
         [SetUp]
@@ -24,7 +27,8 @@ namespace YachtDice.Tests
 
             registry = new ModifierRegistry(5);
             inventory = new InventoryModel(registry);
-            shop = new ShopModel(bank, inventory);
+            diceCollection = new DiceCollection();
+            shop = new ShopModel(bank, inventory, diceCollection);
         }
 
         [TearDown]
@@ -97,8 +101,8 @@ namespace YachtDice.Tests
         [Test]
         public void TryPurchase_FiresPurchaseEvent()
         {
-            ModifierDefinition purchased = null;
-            shop.OnItemPurchased += def => purchased = def;
+            IShopItem purchased = null;
+            shop.OnItemPurchased += item => purchased = item;
 
             var mod = CreateDef("test", shopPrice: 100);
 
@@ -134,5 +138,40 @@ namespace YachtDice.Tests
 
             Assert.AreEqual(ShopItemState.Owned, shop.GetItemState(mod));
         }
+
+        [Test]
+        public void TryPurchase_DieItem_AddsToDiceCollection()
+        {
+            var die = DieDefinitionSO.CreateForTest<StandardDieSO>("test_die", shopPrice: 100);
+
+            bool result = shop.TryPurchase(die);
+
+            Assert.IsTrue(result);
+            Assert.AreEqual(400, bank.Balance);
+            Assert.AreEqual(1, diceCollection.OwnedDice.Count);
+        }
+
+        [Test]
+        public void TryPurchase_DieItem_CannotBeBoughtTwice()
+        {
+            var die = DieDefinitionSO.CreateForTest<StandardDieSO>("unique_die", shopPrice: 100);
+
+            shop.TryPurchase(die);
+            bool secondResult = shop.TryPurchase(die);
+
+            Assert.IsFalse(secondResult);
+            Assert.AreEqual(400, bank.Balance);
+            Assert.AreEqual(1, diceCollection.OwnedDice.Count);
+        }
+
+        [Test]
+        public void GetItemState_Die_Owned_AfterPurchase()
+        {
+            var die = DieDefinitionSO.CreateForTest<StandardDieSO>("die1", shopPrice: 50);
+
+            shop.TryPurchase(die);
+
+            Assert.AreEqual(ShopItemState.Owned, shop.GetItemState(die));
+        }
     }
 }