Fix chart tasks failing with findElementInShadowDOM not defined

When all init scripts are merged into a single string and registered
via add_init_script, function declarations are not accessible from
outside the init script context (e.g. via iframe.evaluate_handle).
Explicitly assigning the function to window ensures it is globally
accessible regardless of how the merged script is scoped.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: aldro61

src/browsergym/workarena/tasks/utils/js_utils.js

@@ -34,6 +34,9 @@ function findElementInShadowDOM(selector, root = document) {
     // Return null if the element is not found in any shadow root
     return null;
 }
+// Explicitly expose on window so it is accessible via frame.evaluate_handle()
+// when all init scripts are merged into a single string (see base.py).
+window.findElementInShadowDOM = findElementInShadowDOM;
 
 
 /**