So the operator can click through the page on their own machine before it is delivered: cmd/mail-page-dev
serves internal/web's real handlers on 127.0.0.1 alone, over invented mail in two accounts and an in-memory
mail reading that fills every section, with an always-signed-in stand-in; nothing reaches the bus, a
database, Keycloak or a mail server. -now fixes today. The README says how to run it and what is a stand-in.