feat: transition from Hyprland to GNOME desktop environment

- Updated Bellerophon configuration to include GNOME desktop settings and packages.
- Added GNOME-specific packages and extensions for enhanced user experience.
- Introduced scripts for display management tailored for ZenBook Duo under GNOME.
- Implemented systemd services for automatic display management and backlight control.
- Integrated UWSM for improved session management in Hyprland.
- Enhanced lid monitoring and USB display management scripts for ZenBook Duo.
- Configured keyring support for GNOME and integrated it with PAM.
- Updated display manager settings to enable GDM for GNOME sessions.

hosts/nixos/Bellerophon/default.nix

@@ -74,8 +74,8 @@
       "hosts/common/optional/services/docker.nix"
       "hosts/common/optional/services/tailscale.nix"
       "hosts/common/optional/audio.nix" # pipewire and cli controls
-      "hosts/common/optional/hyprland.nix"
-      "hosts/common/optional/greetd.nix"
+      "hosts/common/optional/gnome.nix"
+      "hosts/common/optional/gdm.nix"
       "hosts/common/optional/flatpak.nix"
       "hosts/common/optional/thermal-management.nix"