lock primitives: power-from-lock, login1 polkit rule, gesture rail progress

seat0-active polkit rule so power off/reboot/suspend stop returning
challenge into a session with no polkit agent on the lock surface.
Lock-surface buttons stay gated behind allowPowerFromLock (opt-in) and
requirePasswordToPower. SystemGestureRail progressive gesture + mission
control nav flag.

packaging/arch/PKGBUILD

@@ -8,7 +8,7 @@ pkgdesc="Sovereign agent substrate — server, TUI, surfaces"
 arch=('aarch64' 'x86_64')
 url="https://github.com/Fimeg/souveraine"
 license=('MIT')
-depends=('gcc-libs')
+depends=('gcc-libs' 'polkit')
 makedepends=('cargo' 'git')
 options=('!lto')
 
@@ -44,5 +44,12 @@ package() {
     install -Dm644 packaging/arch/souveraine.sysusers \
         "$pkgdir/usr/lib/sysusers.d/souveraine.conf"
 
+    # Let the active local session power off / reboot / suspend / hibernate
+    # without an interactive polkit challenge — otherwise the lock surface
+    # (no agent above session lock) silently no-ops these and every shutdown
+    # is a fastboot hard-reboot.
+    install -Dm644 packaging/arch/souveraine-login1.rules \
+        "$pkgdir/etc/polkit-1/rules.d/49-souveraine-login1.rules"
+
     install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
 }