The 'latest' Zitadel image requires the Login UI v2, which runs as a separate
'login' container this stack doesn't deploy, so OIDC redirected to /ui/v2/login
and returned {code:5, Not Found}. provision.ps1 now disables the loginV2
requirement via the feature API so OIDC uses the built-in /ui/login. Also
applied to the running instance.