feat(taygeta): switch to a violet-magenta wallpaper

Its old nebula-cyan-yellow (seed #0a2a4a, blue 210) clashed with
merope's towers-ice (blue 213). Switch to samurai-cyberpunk-pink-green
(seed #a63ee1), a vivid violet-magenta that fills the empty ~280 gap and
sits clear of every other home's seed color.

home/gabriel/taygeta.nix

@@ -1,5 +1,5 @@
 {pkgs, ...}: {
   imports = [./global];
   # Cyan
-  wallpaper = pkgs.wallpapers.nebula-cyan-yellow;
+  wallpaper = pkgs.wallpapers.samurai-cyberpunk-pink-green;
 }