Rewrite moonlock from Python to Rust (v0.4.0)

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.

pkg/PKGBUILD

@@ -4,24 +4,21 @@
 # Maintainer: Dominik Kressler
 
 pkgname=moonlock-git
-pkgver=0.2.0.r0.g7cee4f4
+pkgver=0.4.0.r0.g0000000
 pkgrel=1
 pkgdesc="A secure Wayland lockscreen with GTK4, PAM and fingerprint support"
-arch=('any')
+arch=('x86_64')
 url="https://gitea.moonarch.de/nevaforget/moonlock"
 license=('MIT')
 depends=(
-    'python'
-    'python-gobject'
     'gtk4'
     'gtk4-layer-shell'
+    'gtk4-session-lock'
     'pam'
 )
 makedepends=(
     'git'
-    'python-build'
-    'python-installer'
-    'python-hatchling'
+    'cargo'
 )
 optdepends=(
     'fprintd: fingerprint authentication support'
@@ -38,13 +35,12 @@ pkgver() {
 
 build() {
     cd "$srcdir/moonlock"
-    rm -rf dist/
-    python -m build --wheel --no-isolation
+    cargo build --release --locked
 }
 
 package() {
     cd "$srcdir/moonlock"
-    python -m installer --destdir="$pkgdir" dist/*.whl
+    install -Dm755 target/release/moonlock "$pkgdir/usr/bin/moonlock"
 
     # PAM configuration
     install -Dm644 config/moonlock-pam "$pkgdir/etc/pam.d/moonlock"