refactor 5:

- MapData.cs 现在会携带战斗初始上下文：
    - InitialCoin
    - 建塔 TowerStatsData 快照
    - TryConsumeCoin / AddCoin 运行时回调
- CombatLoadingState.cs 负责从 CombatInRunResourceManager 读取 coin 和 build stats 快照，组装 MapData 后再交给加载链。
- CombatLoadSession.cs 改成接收外部构造好的 MapData，不再自己只塞一个 LevelId。
- CombatScheduler.cs 不再在 Start() 里直接发起地图加载，加载细节回到 CombatLoadingState。
- MapEntity.cs 已经不再直接读 GameEntry.CombatNode 的 coin / build count / build stats，也不再通过它做 coin 读写：
    - 初始 coin 和 build stats 从 MapData 读取
    - 后续 coin 通过 CombatCoinChangedEventArgs 同步
    - 建塔/升级/拆塔时的 coin 变更通过 MapData 注入回调执行

Assets/GameMain/Scripts/Entity/EntityData/MapData.cs

@@ -1,4 +1,7 @@
 using System;
+using System.Collections.Generic;
+using GeometryTD.Definition;
+using GeometryTD.CustomUtility;
 using UnityEngine;
 
 namespace GeometryTD.Entity.EntityData
@@ -7,6 +10,11 @@ namespace GeometryTD.Entity.EntityData
     public class MapData : EntityDataBase
     {
         [SerializeField] private int _levelId = 0;
+        [SerializeField] private int _initialCoin = 0;
+        [SerializeField] private TowerStatsData[] _buildTowerStatsSnapshot = Array.Empty<TowerStatsData>();
+
+        [NonSerialized] private Func<int, bool> _tryConsumeCoin;
+        [NonSerialized] private Action<int> _addCoin;
 
         public MapData(int entityId, int levelId, Vector3 position) : this(entityId, 0, levelId, position)
         {
@@ -18,10 +26,110 @@ namespace GeometryTD.Entity.EntityData
             Position = position;
         }
 
+        public MapData(
+            int entityId,
+            int typeId,
+            int levelId,
+            Vector3 position,
+            int initialCoin,
+            IReadOnlyList<TowerStatsData> buildTowerStatsSnapshot,
+            Func<int, bool> tryConsumeCoin,
+            Action<int> addCoin) : base(entityId, typeId)
+        {
+            _levelId = levelId;
+            Position = position;
+            _initialCoin = Mathf.Max(0, initialCoin);
+            SetBuildTowerStatsSnapshot(buildTowerStatsSnapshot);
+            _tryConsumeCoin = tryConsumeCoin;
+            _addCoin = addCoin;
+        }
+
         public int LevelId
         {
             get => _levelId;
             set => _levelId = value;
         }
+
+        public int InitialCoin
+        {
+            get => _initialCoin;
+            set => _initialCoin = Mathf.Max(0, value);
+        }
+
+        public int CurrentBuildTowerCount => _buildTowerStatsSnapshot != null ? _buildTowerStatsSnapshot.Length : 0;
+
+        public void BindCombatCallbacks(Func<int, bool> tryConsumeCoin, Action<int> addCoin)
+        {
+            _tryConsumeCoin = tryConsumeCoin;
+            _addCoin = addCoin;
+        }
+
+        public bool TryConsumeCoin(int coin)
+        {
+            int requiredCoin = Mathf.Max(0, coin);
+            if (requiredCoin <= 0)
+            {
+                return true;
+            }
+
+            return _tryConsumeCoin != null && _tryConsumeCoin.Invoke(requiredCoin);
+        }
+
+        public void AddCoin(int coin)
+        {
+            int amount = Mathf.Max(0, coin);
+            if (amount <= 0)
+            {
+                return;
+            }
+
+            _addCoin?.Invoke(amount);
+        }
+
+        public bool TryGetBuildTowerStats(int buildIndex, out TowerStatsData stats)
+        {
+            stats = null;
+            if (_buildTowerStatsSnapshot == null || buildIndex < 0 || buildIndex >= _buildTowerStatsSnapshot.Length)
+            {
+                return false;
+            }
+
+            TowerStatsData sourceStats = _buildTowerStatsSnapshot[buildIndex];
+            if (sourceStats == null)
+            {
+                return false;
+            }
+
+            stats = InventoryCloneUtility.CloneTowerStats(sourceStats);
+            return stats != null;
+        }
+
+        public void SetBuildTowerStatsSnapshot(IReadOnlyList<TowerStatsData> buildTowerStatsSnapshot)
+        {
+            if (buildTowerStatsSnapshot == null || buildTowerStatsSnapshot.Count <= 0)
+            {
+                _buildTowerStatsSnapshot = Array.Empty<TowerStatsData>();
+                return;
+            }
+
+            _buildTowerStatsSnapshot = new TowerStatsData[buildTowerStatsSnapshot.Count];
+            for (int i = 0; i < buildTowerStatsSnapshot.Count; i++)
+            {
+                _buildTowerStatsSnapshot[i] = InventoryCloneUtility.CloneTowerStats(buildTowerStatsSnapshot[i]);
+            }
+        }
+
+        public MapData CloneForEntity(int entityId, Vector3 position)
+        {
+            return new MapData(
+                entityId,
+                TypeId,
+                _levelId,
+                position,
+                _initialCoin,
+                _buildTowerStatsSnapshot,
+                _tryConsumeCoin,
+                _addCoin);
+        }
     }
 }