feat(stage): 提供tmagicRuntimeReady message事件通知

packages/stage/src/StageCore.ts

@@ -230,11 +230,11 @@ export default class StageCore extends EventEmitter {
    * 挂载Dom节点
    * @param el 将stage挂载到该Dom节点上
    */
-  public mount(el: HTMLDivElement): void {
+  public async mount(el: HTMLDivElement) {
     this.container = el;
     const { mask, renderer } = this;
 
-    renderer.mount(el);
+    await renderer.mount(el);
     mask.mount(el);
 
     this.emit('mounted');

packages/stage/src/StageRender.ts

@@ -121,5 +121,12 @@ export default class StageRender extends EventEmitter {
     }
 
     this.emit('onload');
+
+    this.contentWindow.postMessage(
+      {
+        tmagicRuntimeReady: true,
+      },
+      '*',
+    );
   };
 }