[Refactor] Add folder-based namespaces to all C# scripts

Wrap all 39 scripts and 6 test files in namespaces matching their folder
structure (e.g. Assets/Scripts/Dice/ → YachtDice.Dice). Add cross-namespace
using directives where types are referenced across modules. Set rootNamespace
in both .asmdef files (YachtDice, YachtDice.Tests).

Namespace mapping:
- YachtDice.Dice — Dice, DiceRoller
- YachtDice.Economy — CurrencyBank
- YachtDice.Game — GameManager, DiceManager, DebugGameInput
- YachtDice.Inventory — InventoryController/Model/SlotView/View
- YachtDice.Modifiers — ModifierData/Effect/Enums/Pipeline/Runtime/Target
- YachtDice.Persistence — SaveData, SaveSystem
- YachtDice.Scoring — CategoryScorer, ScoreResult, ScoringSystem, YachtCategory
- YachtDice.Shop — ShopCatalog/Controller/ItemView/Model/View
- YachtDice.UI — CategoryRowView, DicePanelView, GameController, GameInfoView, ScoreCardView
- YachtDice.Editor — ModifierAssetCreator
- YachtDice.Tests — all test files

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

Assets/Scripts/Tests/Editor/InventoryModelTests.cs

@@ -1,5 +1,10 @@
 using NUnit.Framework;
 using UnityEngine;
+using YachtDice.Inventory;
+using YachtDice.Modifiers;
+
+namespace YachtDice.Tests
+{
 
 public sealed class InventoryModelTests
 {
@@ -153,3 +158,4 @@ public sealed class InventoryModelTests
         Assert.IsTrue(fired);
     }
 }
+}

Assets/Scripts/Tests/Editor/ModifierEffectTests.cs

@@ -1,5 +1,10 @@
 using NUnit.Framework;
 using UnityEngine;
+using YachtDice.Modifiers;
+using YachtDice.Scoring;
+
+namespace YachtDice.Tests
+{
 
 public sealed class ModifierEffectTests
 {
@@ -87,3 +92,4 @@ public sealed class ModifierEffectTests
         Assert.AreEqual(1.5f, result.Multiplier, 0.001f);
     }
 }
+}

Assets/Scripts/Tests/Editor/ModifierPipelineTests.cs

@@ -1,6 +1,11 @@
 using System.Collections.Generic;
 using NUnit.Framework;
 using UnityEngine;
+using YachtDice.Modifiers;
+using YachtDice.Scoring;
+
+namespace YachtDice.Tests
+{
 
 public sealed class ModifierPipelineTests
 {
@@ -134,3 +139,4 @@ public sealed class ModifierPipelineTests
         Assert.AreEqual(10, result.FinalScore);
     }
 }
+}

Assets/Scripts/Tests/Editor/SaveSystemTests.cs

@@ -1,6 +1,10 @@
 using System.Collections.Generic;
 using NUnit.Framework;
 using UnityEngine;
+using YachtDice.Persistence;
+
+namespace YachtDice.Tests
+{
 
 public sealed class SaveSystemTests
 {
@@ -86,3 +90,4 @@ public sealed class SaveSystemTests
         Assert.AreEqual(0, loaded.Currency);
     }
 }
+}

Assets/Scripts/Tests/Editor/ScoringSystemTests.cs

@@ -1,6 +1,11 @@
 using System.Collections.Generic;
 using NUnit.Framework;
 using UnityEngine;
+using YachtDice.Scoring;
+using YachtDice.Modifiers;
+
+namespace YachtDice.Tests
+{
 
 public sealed class ScoringSystemTests
 {
@@ -96,3 +101,4 @@ public sealed class ScoringSystemTests
         Assert.AreEqual(50, result.FinalScore);
     }
 }
+}

Assets/Scripts/Tests/Editor/ShopModelTests.cs

@@ -1,5 +1,12 @@
 using NUnit.Framework;
 using UnityEngine;
+using YachtDice.Economy;
+using YachtDice.Inventory;
+using YachtDice.Shop;
+using YachtDice.Modifiers;
+
+namespace YachtDice.Tests
+{
 
 public sealed class ShopModelTests
 {
@@ -128,3 +135,4 @@ public sealed class ShopModelTests
         Assert.AreEqual(ShopItemState.Owned, shop.GetItemState(mod));
     }
 }
+}

Assets/Scripts/Tests/Editor/YachtDice.Tests.Editor.asmdef

@@ -1,6 +1,6 @@
 {
     "name": "YachtDice.Tests.Editor",
-    "rootNamespace": "",
+    "rootNamespace": "YachtDice.Tests",
     "references": [
         "UnityEngine.TestRunner",
         "UnityEditor.TestRunner",