feat(physics): 集成 Rapier2D 物理引擎并修复预览重置问题 (#244)

* feat(physics): 集成 Rapier2D 物理引擎并修复预览重置问题

* fix: 修复 CI 流程并清理代码

packages/physics-rapier2d/src/runtime/index.ts

@@ -0,0 +1,17 @@
+/**
+ * Physics 2D Runtime Entry
+ * 2D 物理运行时入口
+ *
+ * 包含 WASM 依赖，用于实际运行时环境
+ * Contains WASM dependencies, for actual runtime environment
+ */
+
+// Re-export runtime module with WASM
+export { PhysicsRuntimeModule, default as physicsRuntimeModule } from '../PhysicsRuntimeModule';
+
+// Re-export world and system (they have WASM type dependencies)
+export { Physics2DWorld } from '../world/Physics2DWorld';
+export type { Physics2DWorldState } from '../world/Physics2DWorld';
+
+export { Physics2DSystem } from '../systems/Physics2DSystem';
+export type { Physics2DSystemConfig } from '../systems/Physics2DSystem';