Migrate discourse off the cc-ci compose overlay per plan §9 / plan-prefer-env-over-compose-overlay.md:
- recipe_meta: drop UPGRADE_BASE_VERSION + COMPOSE_FILE + CHAOS_BASE_DEPLOY; set APP_START_PERIOD=1200s
via EXTRA_ENV (the recipe-PR exposes start_period: ${APP_START_PERIOD:-5m}); declare upgrade tier N/A
(both published prev bases pin removed bitnami images; Adversary §7.1 granted, REVIEW-2 efe3790).
- delete tests/discourse/compose.ccci-health.yml + install_steps.sh (existed only to copy the overlay).
- DECISIONS.md + STATUS-2 record the §9 guardrail + discourse shape (upgrade N/A, env start_period,
pg_backup restore-hook recipe-PR = 5th data-loss recipe cc-ci caught).
recipe-PR head now 8b8df17 (start_period env var added). Not a claim — run STAGES=install,backup,restore,custom next.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>