keyboardManager: don't append locale layout if already present (#13616)

* keyboardManager: don't append locale layout if already present

_buildGroupStrings() unconditionally appends the locale-derived layout
to the XKB group. When the user's configured layouts already include
the locale layout (e.g. 'ru' with ru_RU.UTF-8 locale), this produces
duplicates like 'us,ru,ru', adding a phantom third layout to the
switcher.

Check whether the locale layout is already present before appending it.

* Rename variable to alreadyIncluded for clarity

Address code review feedback: rename `dominated` to `alreadyIncluded`
for better self-description of the boolean's purpose.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

---------

Co-authored-by: Yuriy Tolpygo <[email protected]>
Co-authored-by: Claude Opus 4.6 <[email protected]>

Author: 3 people

js/ui/keyboardManager.js

@@ -160,7 +160,9 @@ var KeyboardManager = class {
     }
 
     _buildGroupStrings(_group) {
-        let group = _group.concat(this._localeLayoutInfo);
+        let alreadyIncluded = _group.some(g => g.layout === this._localeLayoutInfo.layout &&
+                                                g.variant === this._localeLayoutInfo.variant);
+        let group = alreadyIncluded ? _group : _group.concat(this._localeLayoutInfo);
         let layouts = group.map(g => g.layout).join(',');
         let variants = group.map(g => g.variant).join(',');
         return [layouts, variants];