pinwheel: Replace purple color scheme with grayscale and amber

Terminals, tmux and Emacs share a grayscale palette with amber
accents instead of Dracula, and the desktop bars and menus use a
matching gray background.

hosts/pinwheel/modules/emacs/default.nix

@@ -35,6 +35,8 @@ in
       TIG_EDITOR = "${e}/bin/e $@";
     };
 
+    home.file.".emacs.d/doom-submarine-theme.el".source = ./doom-submarine-theme.el;
+
     home.packages = [
       e
       ec