Seven canaries prove both halves of the server's job:
- GREEN: good apps are reported healthy (good-simple + good-significant)
- RED: broken apps are caught at intended tier (false-green guard + 4 per-tier)
Fixtures: custom-html-bkp-bad (backup tier RED) + custom-html-rst-bad (restore tier RED).
All 7 canaries verified on live server (see STATUS-regression.md for artifacts).
Not wired to per-commit CI — run on-demand: pytest -m canary tests/regression/
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>