Add Niri desktop configuration with integrated utilities

- Introduced a new power menu script using fuzzel for session management.
- Updated Bellerophon configuration to include Niri desktop and its components.
- Removed obsolete README for Niri and consolidated its configuration files.
- Added swayidle and swaylock integration for idle management and screen locking.
- Implemented waybar for status bar functionality with basic configuration.
- Created fuzzel integration for application launching and menu access.
- Added zenbook debugging scripts for display and keyboard diagnostics.
- Migrated keyring and other configurations to streamline Niri setup.
- Enhanced display management with systemd services for better integration.

hosts/common/optional/niri/swaylock.nix

@@ -0,0 +1,9 @@
+{pkgs, ...}: {
+  environment.systemPackages = with pkgs; [swaylock imagemagick];
+
+  # Provide a system-level helper in /etc/profile.d to point to a lock wrapper
+  environment.etc."profile.d/lockwrapper.sh".text = ''
+    #!/bin/sh
+    export LOCK_WRAPPER="${pkgs.swaylock}/bin/swaylock"
+  '';
+}