MapData + Event 解耦已完成一轮收口

- `MapData` 已收口为纯初始化快照，不再承载 coin 写接口委托
- 已新增 `MapEntityLoadContext`
  - 用于把 `MapData` 快照与 coin 命令通道拆开传给地图加载
- `CombatLoadingState` 现在会组装：
  - `MapData`
  - `MapEntityLoadContext`
- `CombatLoadSession` / `EntityExtension.ShowMap(...)` 已切到 `MapEntityLoadContext`
- `MapEntity` 当前通过：
  - `MapEntityLoadContext` 获取初始快照与 coin 命令通道
  - `CombatCoinChangedEventArgs` 同步后续 coin 变化
- 已新增 `MapCombatRuntimeBridge`
  - 收口地图侧 coin 当前值、命令调用与事件订阅
- `MapEntity` 不再自己维护 `_currentCoin` 和 coin 事件订阅样板

Assets/GameMain/Scripts/UI/Combat/UseCase/CombatFinishFormUseCase.cs

@@ -7,7 +7,7 @@ namespace GeometryTD.UI
 {
     public class CombatFinishFormUseCase : IUIUseCase
     {
-        private CombatScheduler _combatScheduler;
+        private ICombatSchedulerHost _combatSchedulerHost;
         private CombatSettlementContext _settlementContext;
         private bool _isSummaryPrepared;
 
@@ -27,14 +27,14 @@ namespace GeometryTD.UI
             _isSummaryPrepared = true;
         }
 
-        public CombatFinishFormUseCase(CombatScheduler combatScheduler)
+        internal CombatFinishFormUseCase(ICombatSchedulerHost combatSchedulerHost)
         {
-            this._combatScheduler = combatScheduler;
+            _combatSchedulerHost = combatSchedulerHost;
         }
 
         public bool TryReturnToMenu()
         {
-            return _combatScheduler.OnCombatFinishReturnRequested();
+            return _combatSchedulerHost != null && _combatSchedulerHost.OnCombatFinishReturnRequested();
         }
 
         private CombatFinishFormRawData BuildModel()
@@ -44,7 +44,7 @@ namespace GeometryTD.UI
                 _settlementContext = null;
             }
 
-            BackpackInventoryData rewardInventory = _settlementContext?.RewardInventory;
+            BackpackInventoryData rewardInventory = _settlementContext?.Summary.RewardInventory;
             if (rewardInventory == null)
             {
                 rewardInventory = InventorySeedUtility.CreateSampleInventory();
@@ -52,8 +52,8 @@ namespace GeometryTD.UI
 
             return new CombatFinishFormRawData
             {
-                DefeatedEnemyCount = Mathf.Max(0, _settlementContext?.DefeatedEnemyCount ?? 0),
-                GainedGold = Mathf.Max(0, _settlementContext?.GainedGold ?? 0),
+                DefeatedEnemyCount = Mathf.Max(0, _settlementContext?.Summary.DefeatedEnemyCount ?? 0),
+                GainedGold = Mathf.Max(0, _settlementContext?.Summary.GainedGold ?? 0),
                 RewardInventory = rewardInventory,
                 CanReturn = true
             };