Third triple audit (quality, performance, security). Key fixes:
- Blur padding offset: texture at (-pad,-pad) prevents edge darkening on all sides
- Wallpaper loads after lock.lock() — disk I/O no longer delays lock acquisition
- begin_verification disconnects old signal handler before registering new one
- resume_async resets failed_attempts to prevent premature exhaustion
- Unknown VerifyStatus with done=true triggers restart instead of hanging
- symlink_metadata() replaces separate is_file()+is_symlink() (TOCTOU)
- faillock_warning dead code removed, blur sigma clamped to [0,100]
- Redundant Zeroizing<Vec<u8>> removed, on_verify_status restricted to pub(crate)
- Warn logging for non-UTF-8 GECOS and avatar path errors
- Default impl for FingerprintListener, 3 new tests (47 total)
Complete rewrite of the Wayland lockscreen from Python/PyGObject to
Rust/gtk4-rs for memory safety in security-critical PAM code and
consistency with the moonset/moongreet Rust ecosystem.
Modules: main, lockscreen, auth (PAM FFI), fingerprint (fprintd D-Bus),
config, i18n, users, power. 37 unit tests.
Security: PAM conversation callback with Zeroizing password, panic hook
that never unlocks, root check, ext-session-lock-v1 compositor policy,
absolute loginctl path, avatar symlink rejection.
