Fix OAuth login navigation - use full page reload instead of SPA navigation

The /api/auth/authentik endpoint is a server redirect, not a Nuxt route.
Changed from navigateTo() to window.location.href for proper HTTP redirect.

nuxt4-app/app/pages/login.vue

@@ -8,8 +8,8 @@ const route = useRoute()
 const redirectPath = route.query.redirect as string || '/'
 
 const login = () => {
-  // Navegar a la ruta de OAuth (ahora en /api/auth/authentik)
-  navigateTo('/api/auth/authentik')
+  // Hacer una navegación completa del navegador (no SPA) al endpoint de OAuth
+  window.location.href = '/api/auth/authentik'
 }
 </script>