Deploy Ex Configuration

DeployEx Windsurf Rules
- This repository is an Elixir library for AWS deploy automation using Terraform and Ansible.
- Prefer DeployEx.Config for configuration; do not call Mix.env at runtime.
- Use ErrorMessage for errors and return {:ok, _} / {:error, ErrorMessage}.
- Use DeployEx.Utils for shell commands and consistent logging.
- ExAws requests must include region and tag resources with Group, Environment, ManagedBy.
- Use === and !== for comparisons plus Enum.empty? and is_nil where appropriate.
- Avoid one or two letter variable names unless they are standard in OTP.
- Do not use Application.put_env in tests.
- Avoid mocking libraries; prefer real modules and fixtures.
- Treat warnings as errors and keep output clean.