A home site forwarded every identity route to auth_base_url, so it never knew
who was visiting and could only ever offer "Sign in". It now runs the OIDC
flow itself and shows "My Account" and, for admins, "Admin" -- both pointing
at the deployment that owns those pages.
There is no user table on a home deployment, so the session cookie carries the
claims we need (username, email, admin flag) rather than a row id. It is
HMAC-signed, so it is tamper-evident, and holds nothing secret. The admin test
mirrors upsert_oidc_user: app_admin_emails or an admin group in the claims.
Also decouples oidc_issuer from auth_base_url. They are different hosts --
Authentik on one, the accounts app on another -- and deriving one from the
other only worked when they happened to coincide. OIDC_ISSUER is now its own
variable, required unless APP_ROLE=home.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
ryan