重构项目结构：整理gitignore，移动source目录到根目录，统一依赖管理

src/ECS/Utils/index.ts

@@ -0,0 +1,7 @@
+// ECS工具类导出
+export { EntityList } from './EntityList';
+export { EntityProcessorList } from './EntityProcessorList';
+export { IdentifierPool } from './IdentifierPool';
+export { Matcher } from './Matcher';
+export { Bits } from './Bits';
+export { ComponentTypeManager } from './ComponentTypeManager';