fix: docker-compose.prod.yml usar red coolify externa (Coolify usa este archivo, no docker-compose.yml)

Coolify usa /artifacts/.../docker-compose.prod.yml en el deploy.
Ese archivo tenía 'whatsapp-network' local bridge — el contenedor nunca
se conectaba a la red 'coolify' donde está el Redis → SERVFAIL en DNS.

Cambios:
- networks: whatsapp-network → coolify (external: true)
- container_name: removido (Coolify asigna el suyo)
- healthcheck: timeout 5s→10s, start_period 30s→60s

docker-compose.prod.yml

@@ -10,7 +10,7 @@ services:
       dockerfile: Dockerfile
       args:
         - APP_ENV=production
-    container_name: whatsapp-app
+    # container_name: NO definir — Coolify asigna su propio nombre
     restart: always
     # Coolify/Traefik gestiona el enrutamiento - no exponer puertos directamente
     expose:
@@ -55,13 +55,13 @@ services:
       - PHP_OPCACHE_ENABLE=1
       
     networks:
-      - whatsapp-network
+      - coolify
     healthcheck:
-      test: ["CMD", "curl", "-f", "http://localhost/health.php"]
+      test: ["CMD-SHELL", "curl -sf http://localhost/health.php || exit 1"]
       interval: 30s
-      timeout: 5s
+      timeout: 10s
       retries: 3
-      start_period: 30s
+      start_period: 60s
 
   # Redis: gestionado como Database Resource en Coolify (externo)
   # Worker: corre dentro del contenedor app vía Supervisor
@@ -74,5 +74,5 @@ volumes:
     driver: local
 
 networks:
-  whatsapp-network:
-    driver: bridge
+  coolify:
+    external: true