fix: wrap custom script content in try-catch to prevent ReferenceError

Fixes FORMBRICKS-V3

User-provided custom scripts may reference undefined variables (like
zp_token), causing ReferenceErrors that break the survey. This fix
wraps inline script content in a try-catch block to catch and log
runtime errors without breaking the survey experience.

The error will be logged to the console with a clear warning message,
allowing self-hosted admins to debug their custom scripts while
ensuring the survey remains functional for end users.

apps/web/modules/survey/link/components/custom-scripts-injector.tsx

@@ -56,9 +56,16 @@ export const CustomScriptsInjector = ({
           newScript.setAttribute(attr.name, attr.value);
         });
 
-        // Copy inline script content
+        // Copy inline script content, wrapped in try-catch to prevent runtime errors
         if (script.textContent) {
-          newScript.textContent = script.textContent;
+          // Wrap inline scripts in try-catch to prevent user script errors from breaking the survey
+          newScript.textContent = `
+try {
+${script.textContent}
+} catch (error) {
+  console.warn("[Formbricks] Error in custom script:", error);
+}
+          `.trim();
         }
 
         document.head.appendChild(newScript);