chore: 更新仓库 URL (ecs-framework → esengine)

仓库已从 esengine/ecs-framework 重命名为 esengine/esengine
更新所有引用旧 URL 的文件

examples/core-demos/src/main.ts

@@ -1,5 +1,5 @@
 import { DEMO_REGISTRY, DemoBase } from './demos';
-import { Core } from '@esengine/ecs-framework';
+import { Core } from '@esengine/esengine';
 
 class DemoManager {
     private demos: Map<string, typeof DemoBase> = new Map();