archinstall's FilesystemHandler.perform_filesystem_operations defaults to
show_countdown=True, which runs a ~4.5s "5...4...3...2...1" warning
(_final_warning) before wiping the disk. That prompt is meant for
archinstall's interactive TUI; in our orchestrated/dashboard install it
renders nowhere and just sleeps silently on every full-disk install.
Pass show_countdown=False, guarded by an introspection check so it stays
safe on newer archinstall releases that dropped both the countdown and the
parameter. Generalize _method_accepts_users into _method_accepts for the
check.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
