Add UTM on hard login redirect

Author: daveearley

frontend/src/api/client.ts

@@ -47,7 +47,9 @@ api.interceptors.response.use(
         if (isAuthError && (!isAllowedUnauthenticatedPath || isManageEventPath)) {
             // Store the current URL before redirecting to the login page
             window?.localStorage?.setItem(PREVIOUS_URL_KEY, window?.location.href);
-            window?.location?.replace(LOGIN_PATH);
+            // Preserve query params (UTM tracking) during redirect
+            const searchParams = window?.location?.search || '';
+            window?.location?.replace(LOGIN_PATH + searchParams);
         }
 
         return Promise.reject(error);