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>

features/desktop/waybar/themes/summer-night/config.jsonc

@@ -73,20 +73,6 @@
     "return-type": "json"
   },
 
-  "custom/voxtype": {
-    "exec": "nomarchy-voxtype-status",
-    "return-type": "json",
-    "format": "{icon}",
-    "format-icons": {
-      "idle": "",
-      "recording": "󰍬",
-      "transcribing": "󰔟"
-    },
-    "tooltip": true,
-    "on-click-right": "nomarchy-voxtype-config",
-    "on-click": "nomarchy-voxtype-model"
-  },
-
     "backlight": {
       "max-length": "4",
       "format": "{icon} {percent}%",