Keycloak admin console unreachable when proxied under a path prefix (limitation)

When Keycloak is reverse-proxied at /keycloak/ (as this chart does for path-based routing mode), the admin console redirects to an unprefixed /admin/ path outside anything the Ingress routes, because Keycloak has no KC_HTTP_RELATIVE_PATH set and nginx has no proxy_redirect rewriting the Location header. Normal login is unaffected; only direct admin console access via the public domain breaks. Flagging as a known limitation/documentation gap rather than requesting a fix, since correcting it risks breaking the currently-working /realms//resources proxy rules.