fix(auth): always redirect to phone login when unauthenticated

After logout or on app start with no/invalid token, the browser URL
might be #/dashboard or #/auth/login. Using addPostFrameCallback to
navigate to phoneLoginRoute once the navigator is ready ensures the
user always lands on the phone login screen.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/providers/auth_provider.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:prosapp_web_app/models/usuario.dart';
 import 'package:prosapp_web_app/providers/professional_provider.dart';
 import 'package:prosapp_web_app/providers/services_provider.dart';
@@ -170,6 +171,7 @@ class AuthProvider extends ChangeNotifier {
     if (token == null) {
       authStatus = AuthStatus.notAuthenticated;
       notifyListeners();
+      _redirectToPhoneLogin();
       return false;
     }
     try {
@@ -183,10 +185,17 @@ class AuthProvider extends ChangeNotifier {
       await _api.deleteToken();
       authStatus = AuthStatus.notAuthenticated;
       notifyListeners();
+      _redirectToPhoneLogin();
       return false;
     }
   }
 
+  void _redirectToPhoneLogin() {
+    SchedulerBinding.instance.addPostFrameCallback((_) {
+      NavigationService.replaceTo(Flurorouter.phoneLoginRoute);
+    });
+  }
+
   Future<void> logout() async {
     await _api.deleteToken();
     authStatus = AuthStatus.notAuthenticated;