- Add .env.example (referenced by README Quick Start; populates
SECRET_KEY/POSTGRES_*/AUTH0_* used by docker-compose).
- Add .dockerignore so `COPY . .` no longer bakes .git, __pycache__,
venv, local data, and secrets into the image.
- Rewrite README Docker Deployment into a single `docker compose
up -d --build` flow on port 5021; fix local-dev access port 5000->5021.
- Drop obsolete `version: '3.8'` from docker-compose.yml.
Co-Authored-By: Claude <noreply@anthropic.com>
