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

server/api/instances/index.get.ts

@@ -0,0 +1,42 @@
+/**
+ * GET /api/instances
+ * List all instances
+ */
+import { query } from '../../utils/database'
+import { baileysManager } from '../../services/baileys/manager'
+
+interface InstanceRow {
+  id: string
+  name: string
+  phone_number: string | null
+  status: string
+  last_connected_at: Date | null
+  created_at: Date
+}
+
+export default defineEventHandler(async (event) => {
+  // Check auth
+  const username = getHeader(event, 'x-authentik-username')
+  if (!username) {
+    throw createError({ statusCode: 401, message: 'Unauthorized' })
+  }
+
+  const result = await query<InstanceRow>(
+    `SELECT id, name, phone_number, status, last_connected_at, created_at
+     FROM instances
+     ORDER BY created_at DESC`
+  )
+
+  // Enrich with live status from manager
+  return result.rows.map(row => {
+    const liveStatus = baileysManager.getStatus(row.id)
+    return {
+      id: row.id,
+      name: row.name,
+      phoneNumber: row.phone_number,
+      status: liveStatus?.status || row.status,
+      lastConnectedAt: row.last_connected_at,
+      createdAt: row.created_at
+    }
+  })
+})