feat: WhatsApp Nucleo con Nuxt 4 + Baileys v7

Reemplazo completo de Evolution API por implementación directa con Baileys.

Características:
- Dashboard completo con Nuxt UI v4
- Soporte para múltiples instancias de WhatsApp
- Conexión via QR code o pairing code
- Persistencia de mensajes en PostgreSQL
- API REST para integraciones externas
- Webhooks con firma HMAC
- SSE para actualizaciones en tiempo real
- Autenticación con Authentik

app/composables/useAuthentik.ts

@@ -0,0 +1,68 @@
+/**
+ * Composable para leer información de usuario de Authentik
+ * Los headers son inyectados por Authentik Proxy Outpost
+ */
+
+interface AuthentikUser {
+  username: string
+  email: string | undefined
+  name: string | undefined
+  groups: string[]
+  uid: string | undefined
+  avatar: string
+}
+
+export const useAuthentik = () => {
+  const authentikUser = useState<AuthentikUser | null>('authentikUser', () => {
+    if (import.meta.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']
+
+      if (!username) {
+        return null
+      }
+
+      return {
+        username,
+        email,
+        name,
+        groups: groups ? groups.split('|').filter(g => g.trim()) : [],
+        uid,
+        avatar: `https://ui-avatars.com/api/?name=${encodeURIComponent(name || username)}&background=075e54&color=fff&size=128`
+      }
+    }
+
+    return null
+  })
+
+  const user = computed(() => authentikUser.value)
+  const isAuthenticated = computed(() => !!user.value)
+
+  const logout = () => {
+    const authentikUrl = useRuntimeConfig().public.authentikUrl || 'https://authentik.nucleoriofrio.com'
+    navigateTo(`${authentikUrl}/flows/-/default/invalidation/`, { external: true })
+  }
+
+  const goToProfile = () => {
+    const authentikUrl = useRuntimeConfig().public.authentikUrl || 'https://authentik.nucleoriofrio.com'
+    navigateTo(`${authentikUrl}/if/user/`, { external: true, open: { target: '_blank' } })
+  }
+
+  const hasGroup = (groupName: string): boolean => {
+    if (!user.value) return false
+    return user.value.groups.includes(groupName)
+  }
+
+  return {
+    user,
+    isAuthenticated,
+    logout,
+    goToProfile,
+    hasGroup
+  }
+}