- sudo -u yichu replaced by NH_RUN_USER env (linux panels running as
  root configure the execution user; empty = current user, darwin
  always direct) — last hardcode outside guarded legacy tools
- logins.html: emit meta refresh only while a login test is running
  (content=0 caused an infinite reload loop)
- deploy/migrate keep their overridable yichu defaults (legacy server
  tools, already parameterized via args/env)