Use TypedConfigService for configuration and never read process.env in feature services. Add DTO validation, tests with mocked persistence, and a matching migration for each entity change. Use Conventional Commits and branches such as feature/, fix/, docs/, and chore/; run npm run lint, npm test, and npm run build before opening a pull request.
Public classes and methods use JSDoc describing purpose, parameters, and return values. Module ownership follows the feature list in ARCHITECTURE.md.