- /logins page: per-source credentials CRUD (write-only password,
  masked display, 600-perm files in etc/news-harvester/logins/),
  recipe availability badge, one-click login test (background thread,
  page polls result)
- nh_login_preflight auto-selects the source's dedicated browser
  instance (port+profile) when caller didn't set one
- panel env carries SKILLS_DIR so recipe detection works in-process