Add selectable Voxtype and Superwhisper dictation (#14552)

* Add selectable dictation backends

* Move dictation migration after repository priority update

* Extract backend-specific dictation installers

* Keep dictation installer dispatcher executable

* Call dictation backend installers directly

* Drop legacy Superwhisper migration and runtime cleanup

* Separate dictation defaults from generic recording protocol

* Add backend-specific dictation removers

* Preserve existing Voxtype selection during upgrade

* Make dictation backend selection safe and retryable

* Show the dictation indicator only for selected Voxtype

* Allow switching away from stopped Superwhisper

* Remove the built-in bar dictation indicator

* Store default dictation selection under defaults

* Rename dictation backend selector to use

* Move dictation removers into their own menu category

shell/plugins/menu/MenuModel.js

@@ -398,6 +398,7 @@ var GUARD_READERS = [
   "omarchy-default-browser",
   "omarchy-default-editor",
   "omarchy-default-terminal",
+  "omarchy-default-dictation",
   "omarchy-dns"
 ]