Login, forced password change, admin layout with every 05 §2 page in the
sidebar (unbuilt ones name their milestone), Users table/cards + drawer
(General tab), one-time temporary passwords, reset password. The last
active admin can't be demoted, deactivated or deleted. Audit diffs only
mask secret strings. scripts/e2e has a dependency-free CDP browser check
for this task's acceptance flow.
Task: M1-T4
