feat(config): add polkit package for desktop authentication

.chezmoidata/packages.yaml

@@ -75,6 +75,10 @@ packages:
         # noctalia-git, which conflicts with it
         - noctalia
         - xwayland-satellite
+        # polkitd (D-Bus activated, no unit to enable); Noctalia's built-in
+        # agent answers its prompts (dot_config/noctalia/config.toml), and
+        # niri still starts polkit-gnome
+        - polkit
         - polkit-gnome
         - uwsm
         - xdg-user-dirs