GitLab CI mechanics, any instance or tier: rules, includes, scans, releases, Pages. TRIGGER when: editing `.gitlab-ci.yml`, `.gitlab/ci/`, `.gitlab/changelog_config.yml` or a CI/CD component `templates/*.yml`; setting up CI on GitLab; user asks about GitLab CI rules, runners, schedules, the vulnerability report, Releases or Pages. SKIP when: the repo is on GitHub (`github-actions-conventions`). Load `ci-conventions` alongside.
