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

test/shell.d/menu-test.sh

@@ -325,6 +325,7 @@ assertDeepEqual(
   [
     'remove.package',
     'remove.ai',
+    'remove.dictation',
     'remove.service',
     'remove.development',
     'remove.theme',
@@ -336,7 +337,7 @@ assertDeepEqual(
     'remove.preinstalls',
     'remove.security'
   ],
-  'menu orders Remove categories like their Install counterparts, followed by Remove-only categories'
+  'menu keeps the Remove category order'
 )
 assert(
   defaultById['setup.security.passwordless-sudo'].action.includes('omarchy-sudo-passwordless'),