补全 CombatNode 逻辑 + 重构 EnemyManager

- 添加了关卡内的难度系数与掉落
    - 难度系数：每循环一轮波次敌人血量翻倍
    - 道具掉落：按照掉落概率曲线根据波次计算当前爆率，并从新增的道具池里选择道具
    - `CombatResourceManager`：统一维护关卡内资源状态（硬币/金币/道具掉落）
- 重构 `EnemyManager`：
    - `EnemyManager`：编排子服务，不承载具体业务细节
    - `EnemySpawnDirector`：管理刷怪时序
    - `SpawnerResolver`：管理出生点与路径
    - `EnemyLifecycleTracker`：追踪敌人生命周期
    - `EnemyConfigService`：管理敌人配置与倍率

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

@@ -35,6 +35,9 @@ namespace GeometryTD.UI
             LevelThemeType themeType = level != null ? level.LevelThemeType : GameEntry.CombatNode.CurrentThemeType;
             int levelId = level != null ? level.Id : 0;
             int baseHpMax = level != null ? level.BaseHp : 0;
+            int enemyHpRateMultiplier = ResolveEnemyHpRateMultiplier(
+                GameEntry.CombatNode.CurrentPhaseIndex,
+                GameEntry.CombatNode.CurrentLevelPhaseCount);
 
             return new CombatInfoFormRawData
             {
@@ -45,9 +48,26 @@ namespace GeometryTD.UI
                 Coin = GameEntry.CombatNode.CurrentCoin,
                 BaseHp = GameEntry.CombatNode.CurrentBaseHp,
                 BaseHpMax = baseHpMax,
+                EnemyHpRateMultiplier = enemyHpRateMultiplier,
                 CanPause = true,
                 CanEnd = GameEntry.CombatNode.CanEndCombat
             };
         }
+
+        private static int ResolveEnemyHpRateMultiplier(int currentPhaseIndex, int totalPhaseCount)
+        {
+            if (currentPhaseIndex <= 0 || totalPhaseCount <= 0)
+            {
+                return 1;
+            }
+
+            int completedLoopCount = UnityEngine.Mathf.Max(0, (currentPhaseIndex - 1) / totalPhaseCount);
+            if (completedLoopCount >= 30)
+            {
+                return int.MaxValue;
+            }
+
+            return 1 << completedLoopCount;
+        }
     }
 }