feat: implement sidebar components and authentication flow

- Added sidebar menu components including sidebar-menu-item, sidebar-menu-skeleton, sidebar-menu-sub-button, sidebar-menu-sub-item, sidebar-menu-sub, sidebar-menu, sidebar-provider, sidebar-rail, sidebar-separator, sidebar-trigger, and sidebar.
- Introduced skeleton loading states for sidebar items.
- Integrated tooltip components for enhanced user interaction.
- Developed mobile responsiveness using media queries.
- Established authentication flow with Keycloak, including login, logout, and token management.
- Implemented server-side redirection based on authentication status.
- Enhanced error handling and logging for authentication processes.

frontend/.env.example

@@ -1,10 +1,10 @@
 # Environment variables para frontend
-PUBLIC_API_URL=http://localhost:8000/api/
+VITE_API_URL=http://localhost:8000/api/
 
 # Configuración de Keycloak para SSO
-PUBLIC_KEYCLOAK_URL=http://localhost:8080
-PUBLIC_KEYCLOAK_REALM=master
-PUBLIC_KEYCLOAK_CLIENT_ID=anexo76-frontend
+VITE_KEYCLOAK_URL=http://localhost:8080
+VITE_KEYCLOAK_REALM=master
+VITE_KEYCLOAK_CLIENT_ID=anexo76-frontend
 
 # Opcional: Habilitar/deshabilitar proveedores SSO
 PUBLIC_ENABLE_MICROSOFT_SSO=true