- gem dotenv loads .env (and .env.<environment>[.local]) at startup; real environment variables take precedence. - database.yml takes host, port, user, password and name from NUMOLUS_DATABASE_*; the database is called numolus by default. - .env.example documents every setting; .env itself stays ignored. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>