fix: handle window property access in sandboxed environments

Wraps window.self === window.top check in try-catch to prevent
TypeError in Instagram iOS WebView where window.webkit.messageHandlers
is undefined. Defaults to false if error occurs.

Fixes FORMBRICKS-PP

packages/surveys/src/components/general/survey.tsx

@@ -169,7 +169,13 @@ export function Survey({
     );
   }, [survey.variables]);
 
-  const autoFocusEnabled = autoFocus ?? window.self === window.top;
+  const autoFocusEnabled = (() => {
+    try {
+      return autoFocus ?? window.self === window.top;
+    } catch {
+      return autoFocus ?? false;
+    }
+  })();
 
   // Block-based navigation: track current block ID instead of question ID
   const [blockId, setBlockId] = useState(() => {