Approved brainstorming design: a config flag that disables AdminUI login,
auto-authenticating every request as 'multi-role-test' with all roles via an
always-succeeding AuthenticationHandler registered under the cookie scheme name.
Default off; enabled in docker-dev (central-1/central-2). AdminUI cookie surface
only; OPC UA LDAP + deploy API key untouched.
Joseph Doherty