Fix fullstack serialization order for adjacent components (#4600)

* fix serialization order

* add regression test

* split out test into a seperate package

* revert logging

* change order

* opinions on structure

* small wait in hydration order test

---------

Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

packages/playwright-tests/fullstack-hydration-order.spec.js

@@ -0,0 +1,17 @@
+// @ts-check
+const { test, expect } = require("@playwright/test");
+
+test("hydration", async ({ page }) => {
+  await page.goto("http://localhost:7979");
+
+  // give time for the page to load and hydrate
+  await page.waitForTimeout(2000);
+
+  // Expect the page to contain a button
+  const button = page.locator("#counter");
+  await expect(button).toContainText("Count 0");
+
+  // Hydration should succeed and clicking the button should increase the count
+  await button.click();
+  await expect(button).toContainText("Count 1");
+});