refactor(nixvim): change back mini.base16 to dedicated nord theme plugin

modules/home-manager/stylix.nix

@@ -1,7 +1,6 @@
 # One Nord palette for everything stylix has a target for: gtk, qt,
-# noctalia, ghostty, nixvim. niri has no target and reads the colors in
-# niri.nix. Only the home-manager module is used, so boot, console and
-# sddm are left alone.
+# noctalia, ghostty. Niri has no target and reads the colors in niri.nix. 
+# Only the home-manager module is used, so boot, console and sddm are left alone.
 
 { pkgs, ... }:
 
@@ -28,6 +27,9 @@
       firefox.enable = false;
       # the bar keeps 0xProto instead of the sans-serif font
       noctalia.fonts.enable = false;
+      # nord.nvim is calmer than the base16 palette, e.g. no line number
+      # background, see nixvim.nix
+      nixvim.enable = false;
       # the hand-built status line in tmux.nix uses ANSI color names, which
       # already follow the terminal palette
       tmux.enable = false;