chore(nix): enable RustDesk and update configurations

- Uncommented `rustdesk.nix` in MX system and added `rustdesk-flutter` to GUI services.
- Disabled `services.rustdesk-server.signal` on X1 system to align with updated settings.

modules/nixos/services/gui/default.nix

@@ -167,6 +167,7 @@ in
         yubikey-personalization
         zellij
         gnome-remote-desktop
+        rustdesk-flutter
       ]
       ++ lib.optionals pkgs.stdenv.targetPlatform.isx86_64 (
         with pkgs;

systems/x86_64-linux/mx/default.nix

@@ -15,7 +15,7 @@
     ./nginx.nix
     ./postgresql.nix
     ./rspamd.nix
-    # ./rustdesk.nix
+    ./rustdesk.nix
     ./users.nix
   ];
 

systems/x86_64-linux/x1/default.nix

@@ -11,7 +11,8 @@ with lib.metacfg;
     ./hardware-configuration.nix
   ];
 
-  services.rustdesk-server.enable = true;
+  services.rustdesk-server.signal.enable = false;
+
   services.tailscale.enable = true;
 
   services.cratedocs-mcp.enable = true;