F03-01: go-oidc embeds the provider's response body in its error for a
non-200 discovery response, which cmd/server logged at startup. Discovery
now runs through a status-recording transport and a non-200 response is
reported as "provider answered HTTP <status>" only; transport errors keep
their cause. A test with a sentinel body proves it reaches neither the
error nor the log.
F03-02: the CSRF middleware exempts only GET, so HEAD and OPTIONS under
/api/v1 without X-MealQuest-CSRF get 403 csrf, matching CONTEXT.MD.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>