Migrate to Docker Compose structure (if usable alongside GH Actions)

[anth-volk]

This would theoretically allow us to more cleanly specify config

[nwoodruff-co]

@PolicyEngine could you try doing this in a PR

[policyengine]

Created PR #1101 to add Docker Compose structure for local development and CI.

What's included:

• docker-compose.yml with services for production API, development (hot-reload), and testing
• .env.example with documented environment variables
• Updated Dockerfile.build for better Docker Compose integration
• New make docker-* commands for common operations
• Updated README with quick start guide

Usage:

cp .env.example .env
make docker-up        # Start API
make docker-dev       # Development with hot-reload
make docker-test      # Run tests

This works alongside the existing GitHub Actions - no changes to CI/CD required. The Docker Compose setup provides a cleaner way to specify config for local development as mentioned in the issue.

PR: #1101