scripts/uninstall-linux-x11.sh — strips ahfail from common PAM service
files and removes binaries (via ninja uninstall or known paths).
scripts/uninstall-macos.sh — strips ahfail from screensaverui/screensaver
and removes /usr/local/lib/ahfail/.
README: add Uninstall section covering all four cases (X11, Wayland,
Homebrew macOS, manual macOS).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
