Add enemy respawner and related components for room lifecycle management

- Implemented EnemyRespawner to manage enemy spawning and respawning within rooms.
- Added IRoomLifecycle interface for room activation and dormancy handling.
- Created supporting classes and metadata for enemy perception and threat assessment.
- Established streaming system components for room state management and transitions.
- Added necessary metadata files for new scripts to ensure proper integration with Unity.

Assets/_Game/Scripts/World/Streaming/RoomHandle.cs

@@ -96,6 +96,13 @@ namespace BaseGames.World.Streaming
         {
             if (State == RoomState.Unloaded || State == RoomState.Unloading || !_sceneHandle.IsValid()) yield break;
 
+            // 若正处于加载中，等待加载完成后再卸载（Addressables 不支持对未完成的句柄直接卸载）
+            if (State == RoomState.Loading)
+            {
+                while (!_sceneHandle.IsDone)
+                    yield return null;
+            }
+
             // Active 状态先走 Deactivate，再设置 Unloading
             bool needsDeactivate = State == RoomState.Active ||
                                    State == RoomState.Activating ||