feat: reverse proxy config

[taygumus]

Reverse Proxy Configuration Refactor

Summary

This PR refactors the production setup to delegate HTTPS and certificate management to an external reverse proxy.

Changes

• Removed Certbot service and related renewal/issue scripts
• Removed certificate volumes and ACME challenge handling from the WordPress stack
• Simplified production Nginx configuration to serve HTTP only
• Attached the nginx service to the external proxy network
• Introduced a stable Docker network alias (wp-docker-stack-nginx) for reverse proxy upstream resolution

Resulting Architecture

• TLS termination handled by the reverse proxy
• WordPress stack Nginx serves plain HTTP internally
• Reverse proxy routes traffic via Docker network alias
• Improved scalability and cleaner separation of concerns

This makes the stack production-ready, proxy-friendly, and easier to scale across multiple projects.