refactor: replace plasma-bigscreen role with kodi

Remove the custom plasma-bigscreen role and package, switching boxy and
gym-box to use the existing kodi role instead. The kodi role now
supports wayland and appLauncherServer with the same options.

machines/boxy/configuration.nix

@@ -7,10 +7,10 @@
 with lib;
 
 {
-  imports =
-    [ # Include the results of the hardware scan.
-      ./hardware-configuration.nix
-    ];
+  imports = [
+    # Include the results of the hardware scan.
+    ./hardware-configuration.nix
+  ];
 
   roles = {
     audio.enable = true;
@@ -22,11 +22,12 @@ with lib;
       sddm = true;
       wayland = true;
     };
-    plasma-bigscreen = {
+    kodi = {
       enable = true;
       autologin = true;
-      jellyfinScaleFactor = 1.0;
+      wayland = true;
       appLauncherServer.enable = true;
+      jellyfinScaleFactor = 1.0;
     };
     nfs-mounts.enable = true;
     users.enable = true;