拆分 MapEntity 职责

- TowerSelectionPresenter：选中态 + 攻击范围展示
- CombatSelectInputService：点击事件逻辑（位置计算、点击对象识别、组装 CombatSelectFormUserData）
- TowerPlacementService：建造/升级/销毁与塔映射管理
- MapTopologyService：维护地图拓扑结构与寻路缓存

Assets/GameMain/Scripts/CustomComponent/CombatNode/EnemyManager.cs

@@ -5,6 +5,7 @@ using GeometryTD.DataTable;
 using GeometryTD.Definition;
 using GeometryTD.Entity;
 using GeometryTD.Entity.EntityData;
+using GeometryTD.Map;
 using UnityEngine;
 using UnityGameFramework.Runtime;