Rails Maintenance

Identify the requested maintenance mode and use only the matching procedure: setup-environment for first-time setup, apply-code-conventions for path-specific conventions, refactor-code for behavior-preserving cleanup, or a focused engine procedure for engine work.

Preserve the app's configuration and conventions. Run checks relevant to changed files. Do not force TDD, security scans, full-suite runs, documentation, or PR steps when they do not apply. Use a checkpoint for production, security/authorization, deployment, or irreversible changes.