Fix: Move composables and components into app/ directory

- Resolve SSR error "useAuthentik is not defined"
- Follow Nuxt 4 directory structure conventions
- When app/ exists, all app directories must be inside it
- This enables proper auto-import of composables

nuxt4/app/composables/useAuthentik.ts

@@ -0,0 +1,58 @@
+/**
+ * Composable para leer información de usuario de Authentik
+ * Los headers son inyectados por Authentik Proxy Outpost
+ */
+export const useAuthentik = () => {
+  // Leer headers en el servidor y almacenarlos en state
+  const authentikUser = useState('authentikUser', () => {
+    // Solo en el servidor, leer los headers
+    if (process.server) {
+      const headers = useRequestHeaders()
+
+      const username = headers['x-authentik-username']
+      const email = headers['x-authentik-email']
+      const name = headers['x-authentik-name']
+      const groups = headers['x-authentik-groups']
+      const uid = headers['x-authentik-uid']
+
+      // Si no hay username, el usuario no está autenticado
+      if (!username) {
+        return null
+      }
+
+      return {
+        username,
+        email,
+        name,
+        groups: groups ? groups.split('|') : [],
+        uid,
+        // Generar avatar URL usando UI Avatars
+        avatar: `https://ui-avatars.com/api/?name=${encodeURIComponent(name || username)}&background=random&size=128`
+      }
+    }
+
+    return null
+  })
+
+  const user = computed(() => authentikUser.value)
+  const isAuthenticated = computed(() => !!user.value)
+
+  const logout = () => {
+    // Authentik Proxy Outpost maneja el logout
+    // Redirigir a /outpost.goauthentik.io/sign_out
+    navigateTo('/outpost.goauthentik.io/sign_out', { external: true })
+  }
+
+  const goToProfile = () => {
+    // URL de perfil de Authentik
+    const authentikUrl = useRuntimeConfig().public.authentikUrl || 'https://authentik.nucleoriofrio.com'
+    navigateTo(`${authentikUrl}/if/user/`, { external: true, open: { target: '_blank' } })
+  }
+
+  return {
+    user,
+    isAuthenticated,
+    logout,
+    goToProfile
+  }
+}