Read INFINITO_LIFECYCLES from default.env via a new tested_lifecycles() helper; derive TESTED_LIFECYCLES, the README overview envelope, the guide-select role filter, and the invokable-lifecycle lint from it. Add "maintained" to the envelope and drop the redundant hardcoded "alpha beta rc stable" strings from workflows, CLI help, and docs.
Guide selection now skips pre-alpha/eol roles (153 -> 117 testable).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>