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/fixtures/indicator-contract/shell.qml

@@ -198,16 +198,6 @@ ShellRoot {
         root.assertTrue(root.commandCount("omarchy-capture-screenrecording --stop-recording") === 1, "Screen Recording left click stops active recording")
       }
 
-      var dictation = root.createIndicator("Dictation")
-      if (dictation) {
-        dictation.moduleName = "Dictation"
-        root.injectBar(dictation)
-        dictation.triggerPress(Qt.LeftButton)
-        dictation.triggerPress(Qt.RightButton)
-        root.assertTrue(root.commandCount("omarchy-voxtype-config") === 2, "Dictation clicks run config command")
-        root.assertTrue(root.commandCount("omarchy-voxtype-model") === 0, "Dictation clicks do not run model command")
-      }
-
       var stayAwake = root.createIndicator("StayAwake")
       if (stayAwake) {
         stayAwake.moduleName = "StayAwake"