[Fase 3] Etapa 9 - Docker Compose Final

## Objetivo
Criar o docker-compose.yml final orquestrando todos os servicos.

## Tarefas
- [ ] Orquestrar: postgres, redis, config-server, eureka-server, gateway, auth-service, catalog-service, loan-service, prometheus, grafana, zipkin
- [ ] Configurar depends_on com healthchecks
- [ ] Testar subida completa do ambiente

## Commit
chore(docker): add full microservices docker-compose