fix: wrap auth views in AuthLayout and remove duplicate logo from PhoneLoginView

- admin_handlers: wrap PhoneLoginView, LoginView, RegisterView in AuthLayout
  so the gradient split panel / header renders correctly
- phone_login_view: remove standalone logo block (AuthLayout provides it)
  and remove unused phone_form_provider import

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

lib/router/admin_handlers.dart

@@ -1,4 +1,5 @@
 import 'package:prosapp_web_app/providers/auth_provider.dart';
+import 'package:prosapp_web_app/ui/layouts/auth/auth_layout.dart';
 import 'package:prosapp_web_app/ui/views/dashboard_view.dart';
 import 'package:prosapp_web_app/ui/views/login_view.dart';
 import 'package:prosapp_web_app/ui/views/phone_login_view.dart';
@@ -9,9 +10,8 @@ import 'package:provider/provider.dart';
 class AdminHandlers {
   static Handler phone = Handler(handlerFunc: (context, params) {
     final authProvider = Provider.of<AuthProvider>(context!);
-
     if (authProvider.authStatus == AuthStatus.notAuthenticated) {
-      return const PhoneLoginView();
+      return const AuthLayout(child: PhoneLoginView());
     } else {
       return const DashboardView();
     }
@@ -19,9 +19,8 @@ class AdminHandlers {
 
   static Handler login = Handler(handlerFunc: (context, params) {
     final authProvider = Provider.of<AuthProvider>(context!);
-
     if (authProvider.authStatus == AuthStatus.notAuthenticated) {
-      return const LoginView();
+      return const AuthLayout(child: LoginView());
     } else {
       return const DashboardView();
     }
@@ -29,9 +28,8 @@ class AdminHandlers {
 
   static Handler register = Handler(handlerFunc: (context, params) {
     final authProvider = Provider.of<AuthProvider>(context!);
-
     if (authProvider.authStatus == AuthStatus.notAuthenticated) {
-      return const RegisterView();
+      return const AuthLayout(child: RegisterView());
     } else {
       return const DashboardView();
     }