The cookie that carries a sign-in across the provider was signed with a
key each process made for itself, so with two control planes behind a
balancer a callback reaching the other one was refused as tampered — half
of all sign-ins. The key is now the store's oidc-state secret, sealed like
the others and the same on every control plane.
Changelog: the fixes since v0.14.2.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
