feat(moongreet-git): install moongreet polkit rule

Ships config/polkit/50-moongreet-power.rules (new in moongreet v0.8.3)
to /usr/share/polkit-1/rules.d/ so the greeter user can reboot and
power off without authentication.

Reset pkgrel to 1 — the pkgver bump to 0.8.3 will be picked up by
pkgver-bot after the moongreet tag is pushed.

moongreet-git/PKGBUILD

@@ -5,7 +5,7 @@
 
 pkgname=moongreet-git
 pkgver=0.8.3.r0.g48d363b
-pkgrel=2
+pkgrel=1
 pkgdesc="A greetd greeter for Wayland with GTK4 and Layer Shell"
 arch=('x86_64')
 url="https://gitea.moonarch.de/nevaforget/greetd-moongreet"
@@ -42,6 +42,10 @@ package() {
     # Greeter config
     install -Dm644 config/moongreet.toml "$pkgdir/etc/moongreet/moongreet.toml"
 
+    # Polkit rule — allow the greeter user to reboot/power off
+    install -Dm644 config/polkit/50-moongreet-power.rules \
+        "$pkgdir/usr/share/polkit-1/rules.d/50-moongreet-power.rules"
+
     # Cache directories
     install -dm700 "$pkgdir/var/cache/moongreet"
     install -dm700 "$pkgdir/var/cache/moongreet/last-session"