feat: Implement Room Streaming System

- Add RoomStreamingManager to manage room loading and unloading based on player proximity.
- Create StreamingBudgetConfigSO for memory and performance budgeting of the streaming system.
- Introduce TransitionDirector to handle seamless and atmospheric fade transitions between rooms.
- Develop WorldGraph to represent room connectivity and facilitate neighbor queries and distance calculations.
- Implement RoomNode and RoomEdge classes to structure room data and connections.

Assets/_Game/Scripts/Editor/Scene/SceneScaffoldTools.cs

@@ -12,6 +12,8 @@ using BaseGames.UI.MainMenu;
 using BaseGames.UI.Menus;
 using BaseGames.UI.Splash;
 using BaseGames.World;
+using BaseGames.World.Map;
+using BaseGames.World.Streaming;
 using PathBerserker2d;
 using Unity.Cinemachine;
 using UnityEditor;
@@ -230,6 +232,9 @@ namespace BaseGames.Editor
 
             AddScaffoldNote(hudRootGo, "HUDController 已挂载。其内部图片/文本/图标 Prefab 依赖较多，需后续手工补 UI 资源与事件频道。", report);
 
+            // ── 流式加载系统 ──────────────────────────────────────────────────
+            ScaffoldStreamingSystem(services, report);
+
             MarkDirtyAndLog("Persistent 场景脚手架", root, report);
         }
 
@@ -392,6 +397,79 @@ namespace BaseGames.Editor
             MarkDirtyAndLog("Game Room 脚手架", root, report);
         }
 
+        // ─────────────────────────────────────────────────────────────────────
+        // 流式加载系统（RoomStreamingManager + TransitionDirector）
+        // ─────────────────────────────────────────────────────────────────────
+
+        /// <summary>
+        /// 在 [Services] 下创建或更新 SYS_RoomStreamingManager，
+        /// 挂载 <see cref="RoomStreamingManager"/> 与 <see cref="TransitionDirector"/>，
+        /// 并自动绑定已存在的事件频道与配置资产。
+        /// </summary>
+        private static void ScaffoldStreamingSystem(Transform services, List<string> report)
+        {
+            // 预算配置 SO（不存在时自动创建）
+            StreamingBudgetConfigSO budgetConfig = EnsureStreamingBudgetConfigAsset(report);
+
+            // MapDatabaseSO（查找已存在的资产）
+            Object mapDbAsset = FindFirstAssetByType<MapDatabaseSO>("MapDatabase", "MAP_Database", "MapDatabaseSO");
+            if (mapDbAsset == null)
+                report.Add("未找到 MapDatabaseSO 资产。请将 MapDatabaseSO 手工赋给 RoomStreamingManager._mapDatabase 与 TransitionDirector._mapDatabase。");
+
+            // ── SYS_RoomStreamingManager GameObject ──────────────────────────
+            GameObject streamingGo = GetOrCreateChild(services, "SYS_RoomStreamingManager").gameObject;
+
+            RoomStreamingManager streamingMgr   = GetOrAddComponent<RoomStreamingManager>(streamingGo);
+            TransitionDirector   transitionDir  = GetOrAddComponent<TransitionDirector>(streamingGo);
+
+            // ── RoomStreamingManager 字段 ─────────────────────────────────────
+            AssignReference(streamingMgr, "_mapDatabase", mapDbAsset);
+            AssignReference(streamingMgr, "_budget",      budgetConfig);
+            AssignAsset(streamingMgr, "_onRoomEntered",   report, false, "EVT_RoomEntered");
+            AssignAsset(streamingMgr, "_onRoomPreloaded", report, false, "EVT_RoomPreloaded");
+
+            // ── TransitionDirector 字段 ───────────────────────────────────────
+            AssignReference(transitionDir, "_streamingManager", streamingMgr);
+            AssignReference(transitionDir, "_mapDatabase",      mapDbAsset);
+            AssignReference(transitionDir, "_budget",           budgetConfig);
+            AssignAsset(transitionDir, "_onFadeOutRequest",          report, false, "EVT_FadeOutRequest");
+            AssignAsset(transitionDir, "_onFadeInRequest",           report, false, "EVT_FadeInRequest");
+            AssignAsset(transitionDir, "_onRegionNameDisplay",       report, false, "EVT_RegionNameDisplay");
+            AssignAsset(transitionDir, "_onSceneWorldStateRestored", report, false, "EVT_SceneWorldStateRestored");
+
+            report.Add("SYS_RoomStreamingManager：流式加载系统已创建。如 EVT_RoomEntered / EVT_RoomPreloaded 频道尚未存在，请通过 DataHub > Streaming 创建后重新运行脚手架。");
+        }
+
+        /// <summary>
+        /// 在 <c>Assets/_Game/Data/Streaming/</c> 下确保默认预算配置 SO 存在。
+        /// 已存在时直接返回；不存在时自动创建 <c>STR_BudgetConfig_Default.asset</c>。
+        /// </summary>
+        private static StreamingBudgetConfigSO EnsureStreamingBudgetConfigAsset(List<string> report)
+        {
+            // 先查找已有资产
+            string[] guids = AssetDatabase.FindAssets("t:StreamingBudgetConfigSO");
+            if (guids != null && guids.Length > 0)
+            {
+                string path = AssetDatabase.GUIDToAssetPath(guids[0]);
+                var existing = AssetDatabase.LoadAssetAtPath<StreamingBudgetConfigSO>(path);
+                if (existing != null)
+                    return existing;
+            }
+
+            // 没有则创建默认资产
+            const string folder    = "Assets/_Game/Data/Streaming";
+            const string assetPath = folder + "/STR_BudgetConfig_Default.asset";
+            EnsureFolder(folder);
+
+            var created = ScriptableObject.CreateInstance<StreamingBudgetConfigSO>();
+            AssetDatabase.CreateAsset(created, assetPath);
+            AssetDatabase.SaveAssets();
+            AssetDatabase.Refresh();
+
+            report.Add($"已自动创建流式加载预算配置：{assetPath}。可在 DataHub > 流式加载 中编辑默认参数。");
+            return created;
+        }
+
         private static void AssignString(Object target, string propertyName, string value, List<string> report = null)
         {
             SerializedObject serializedObject = new SerializedObject(target);