feat: consolidate Kanagawa theme and refine Walker and Limine styling

modules/capabilities/plymouth.nix

@@ -1,7 +1,7 @@
 { ... }:
 {
   flake.modules.nixos.plymouth =
-    { pkgs, ... }:
+    { ... }:
     {
       boot = {
         consoleLogLevel = 3;
@@ -16,8 +16,6 @@
 
         plymouth = {
           enable = true;
-          theme = "spinner_alt";
-          themePackages = [ pkgs.adi1090x-plymouth-themes ];
         };
       };
     };