Add validateLegacyDiscoveryHosts() next to the allowlist in
lib/api/v1/base-url.ts and a unit test that pins the registered
production configuration (app.accounted.se canonical,
app.gnubok.se SKV OAuth pin). The invariant is checked both ways:
the NEXT_PUBLIC_SKV_OAUTH_BASE_URL host must be reflectable by
discovery (canonical or allowlisted), and every allowlist member
must be accounted for by the registered configuration. Drift is
now a red CI test instead of a silent production re-auth failure
near a filing deadline. No runtime behavior changes.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
