Add logo SVG asset and improve authentication error handling

- Added a new logo SVG asset to the AssetsManager for better branding.
- Updated the AuthViewModel to notify listeners on authentication error changes.
- Modified DesktopNavigationWidget to use the new logo SVG with specified dimensions for improved layout.

lib/core/constants/assets.dart

@@ -5,6 +5,7 @@ class AssetsManager {
   static const logoSmall = 'assets/icons/logo_small.svg';
   static const logoBig = 'assets/icons/logo_big.svg';
   static const logoBigPng = 'assets/pngs/logo-big.png';
+  static const logoSvg = 'assets/icons/logo.svg';
 
   //bottom navigation
   static const homeActive = 'assets/icons/home_active.svg';

lib/view_models/auth_view_model.dart

@@ -84,6 +84,7 @@ class AuthViewModel with ChangeNotifier {
         break;
       case Error<LoginResponseModel>():
         _errorMessage = result.error.toString();
+        notifyListeners();
         break;
     }
 

lib/views/shared/desktop_navigation_widget.dart

@@ -47,7 +47,11 @@ class DesktopNavigationWidget extends StatelessWidget {
                 context.read<TabNavigationService>().onTabSelected(0);
               }
             },
-            child: SvgPicture.asset(AssetsManager.logoSmall),
+            child: SizedBox(
+              width: 150,
+              height: 48,
+              child: SvgPicture.asset(AssetsManager.logoSvg),
+            ),
           ),
           const Spacer(),
           _navigationItem(