feat(world-streaming): 添加世界流式加载系统 (#288)

实现基于区块的世界流式加载系统，支持开放世界游戏：

运行时包 (@esengine/world-streaming):
- ChunkComponent: 区块实体组件，包含坐标、边界、状态
- StreamingAnchorComponent: 流式锚点组件（玩家/摄像机）
- ChunkLoaderComponent: 流式加载配置组件
- ChunkStreamingSystem: 区块加载/卸载调度系统
- ChunkCullingSystem: 区块可见性剔除系统
- ChunkManager: 区块生命周期管理服务
- SpatialHashGrid: 空间哈希网格
- ChunkSerializer: 区块序列化

编辑器包 (@esengine/world-streaming-editor):
- ChunkVisualizer: 区块可视化覆盖层
- ChunkLoaderInspectorProvider: 区块加载器检视器
- StreamingAnchorInspectorProvider: 流式锚点检视器
- WorldStreamingPlugin: 完整插件导出

packages/world-streaming/src/WorldStreamingModule.ts

@@ -0,0 +1,50 @@
+import type { IScene, ServiceContainer } from '@esengine/ecs-framework';
+import { ComponentRegistry } from '@esengine/ecs-framework';
+import type { IRuntimeModule, SystemContext } from '@esengine/engine-core';
+import { ChunkComponent } from './components/ChunkComponent';
+import { StreamingAnchorComponent } from './components/StreamingAnchorComponent';
+import { ChunkLoaderComponent } from './components/ChunkLoaderComponent';
+import { ChunkStreamingSystem } from './systems/ChunkStreamingSystem';
+import { ChunkCullingSystem } from './systems/ChunkCullingSystem';
+import { ChunkManager } from './services/ChunkManager';
+
+/**
+ * 世界流式加载模块
+ *
+ * Runtime module for world streaming functionality.
+ *
+ * 提供世界流式加载功能的运行时模块。
+ */
+export class WorldStreamingModule implements IRuntimeModule {
+    private _chunkManager: ChunkManager | null = null;
+
+    get chunkManager(): ChunkManager | null {
+        return this._chunkManager;
+    }
+
+    registerComponents(registry: typeof ComponentRegistry): void {
+        registry.register(ChunkComponent);
+        registry.register(StreamingAnchorComponent);
+        registry.register(ChunkLoaderComponent);
+    }
+
+    registerServices(services: ServiceContainer): void {
+        this._chunkManager = new ChunkManager();
+        services.registerInstance(ChunkManager, this._chunkManager);
+    }
+
+    createSystems(scene: IScene, _context: SystemContext): void {
+        const streamingSystem = new ChunkStreamingSystem();
+        if (this._chunkManager) {
+            streamingSystem.setChunkManager(this._chunkManager);
+        }
+        scene.addSystem(streamingSystem);
+        scene.addSystem(new ChunkCullingSystem());
+    }
+
+    onSystemsCreated(_scene: IScene, _context: SystemContext): void {
+        // No post-creation setup needed
+    }
+}
+
+export const worldStreamingModule = new WorldStreamingModule();