feat: add MercadoPago payments, subscription service, and webhooks

- MercadoPago PreApproval integration for recurring subscriptions
- Subscription service with caching, manual payment, payment history
- Webhook handler with HMAC-SHA256 signature verification
- Admin endpoints for subscription management and payment links
- Email notifications on payment success/failure/cancellation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/app.ts

@@ -15,6 +15,8 @@ import { usuariosRoutes } from './routes/usuarios.routes.js';
 import { tenantsRoutes } from './routes/tenants.routes.js';
 import fielRoutes from './routes/fiel.routes.js';
 import satRoutes from './routes/sat.routes.js';
+import { webhookRoutes } from './routes/webhook.routes.js';
+import { subscriptionRoutes } from './routes/subscription.routes.js';
 
 const app: Express = express();
 
@@ -47,6 +49,8 @@ app.use('/api/usuarios', usuariosRoutes);
 app.use('/api/tenants', tenantsRoutes);
 app.use('/api/fiel', fielRoutes);
 app.use('/api/sat', satRoutes);
+app.use('/api/webhooks', webhookRoutes);
+app.use('/api/subscriptions', subscriptionRoutes);
 
 // Error handling
 app.use(errorMiddleware);