A better state and alerts

lib/screens/auth/signup_screen.dart

@@ -5,6 +5,7 @@ import 'package:go_router/go_router.dart';
 import '../../providers/auth_provider.dart';
 import '../../providers/tickets_provider.dart';
 import '../../widgets/responsive_body.dart';
+import '../../utils/snackbar.dart';
 
 class SignUpScreen extends ConsumerStatefulWidget {
   const SignUpScreen({super.key});
@@ -46,9 +47,7 @@ class _SignUpScreenState extends ConsumerState<SignUpScreen> {
   Future<void> _handleSignUp() async {
     if (!_formKey.currentState!.validate()) return;
     if (_selectedOfficeIds.isEmpty) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('Select at least one office.')),
-      );
+      showWarningSnackBar(context, 'Select at least one office.');
       return;
     }
     setState(() => _isLoading = true);
@@ -66,9 +65,7 @@ class _SignUpScreenState extends ConsumerState<SignUpScreen> {
       }
     } on Exception catch (error) {
       if (mounted) {
-        ScaffoldMessenger.of(
-          context,
-        ).showSnackBar(SnackBar(content: Text('Sign up failed: $error')));
+        showErrorSnackBar(context, 'Sign up failed: $error');
       }
     } finally {
       if (mounted) {