fix: keep OAuth loading overlay active through saga processing

Agent-Logs-Url: https://github.com/MobilityData/mobilitydatabase-web/sessions/b4256bb5-f74f-4082-9899-f38339538c9a

Co-authored-by: Alessandro100 <18631060+Alessandro100@users.noreply.github.com>

Author: Copilot

src/app/[locale]/sign-in/SignIn.tsx

@@ -97,6 +97,12 @@ export default function SignIn(): React.ReactElement {
     },
   });
 
+  React.useEffect(() => {
+    if (emailLoginError != null) {
+      setIsOAuthLoading(false);
+    }
+  }, [emailLoginError]);
+
   React.useEffect(() => {
     if (userProfileStatus === 'registered') {
       if (searchParams.has('add_feed')) {
@@ -126,7 +132,6 @@ export default function SignIn(): React.ReactElement {
           setIsOAuthLoading(false);
           setShowNoEmailSnackbar(true);
         } else {
-          setIsOAuthLoading(false);
           dispatch(loginWithProvider({ oauthProvider, userCredential }));
         }
       })