- All docker-compose services now use src/.env (prod), src/.env.development (local)
- docker-compose.staging.yml added with staging.conf nginx config
- Root .env removed; all vars consolidated in src/.env
- MARIADB_* vars added to all env files for db service
- .gitignore cleaned up (removed duplicate src/.env entry)
- src/.env.example updated with DB_ROOT_PASSWORD and MARIADB_* vars
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>