fix legacy wrapper

Author: trueadm

packages/svelte/src/legacy/legacy-client.js

@@ -2,7 +2,7 @@
 import { mutable_source, set } from '../internal/client/reactivity/sources.js';
 import { user_pre_effect } from '../internal/client/reactivity/effects.js';
 import { hydrate, mount, unmount } from '../internal/client/render.js';
-import { get } from '../internal/client/runtime.js';
+import { flush_sync, get, } from '../internal/client/runtime.js';
 import { define_property } from '../internal/shared/utils.js';
 
 /**
@@ -110,6 +110,8 @@ class Svelte4Component {
 			recover: options.recover
 		});
 
+		flush_sync();
+
 		this.#events = props.$$events;
 
 		for (const key of Object.keys(this.#instance)) {