Fix contextObject.waitForFunction error in iframe contexts

Co-authored-by: kobenguyent <[email protected]>

Author: Copilot

lib/helper/Playwright.js

@@ -2808,8 +2808,9 @@ class Playwright extends Helper {
 
     return Promise.race([
       // Strategy 1: waitForFunction that checks both body AND title text
+      // Use this.page instead of contextObject because FrameLocator doesn't have waitForFunction
       // Original only checked document.body.innerText, missing title text like "TestEd"
-      contextObject.waitForFunction(
+      this.page.waitForFunction(
         function (text) {
           // Check body text (original behavior)
           if (document.body && document.body.innerText && document.body.innerText.indexOf(text) > -1) {