feat: remove unused voxtype dictation feature

Voxtype voice-typing was a full feature (5 scripts, a waybar widget, a
keybind, and a NixOS option) that this install does not use. The
nomarchy.system.voxtype option had no consumer — nothing read it — so the
widget and SUPER+CTRL+X bind were never actually gated by it.

Removes the scripts, default config, the SUPER+CTRL+X bind, the waybar
module (main + summer-night theme + css), the dead option, the installer
comment, and the docs. SCRIPTS.md/KEYBINDINGS.md regenerated; OPTIONS.md
and SKILL.md hand-updated.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

core/system/options.nix

@@ -206,14 +206,5 @@ in
         most users want this off.
       '';
     };
-
-    voxtype = {
-      enable = lib.mkEnableOption ''
-        voxtype voice-typing integration. NOTE: voxtype is not packaged in
-        nixpkgs — when enabled, install voxtype yourself (e.g. via
-        `home.packages = [ (pkgs.callPackage … {}) ]`). With this off the
-        SUPER+CTRL+X keybinding and waybar widget are no-ops.
-      '';
-    };
   };
 }