fix(electron): respect locale for spellchecker (#8844)

may fix #8837.
fix AF-1712

MacOS automatically do spellcheck based on given text. This only works for Win/Linux.
![image.png](https://graphite-user-uploaded-assets-prod.s3.amazonaws.com/T2klNLEk0wxLh4NRDzhk/25058395-d70a-42a4-b869-c69fa71bc418.png)

packages/frontend/apps/electron/src/main/ui/handlers.ts

@@ -1,6 +1,7 @@
 import { app, nativeTheme, shell } from 'electron';
 import { getLinkPreview } from 'link-preview-js';
 
+import { isMacOS } from '../../shared/utils';
 import { persistentConfig } from '../config-storage/persist';
 import { logger } from '../logger';
 import type { WorkbenchViewMeta } from '../shared-state-schema';
@@ -220,4 +221,15 @@ export const uiHandlers = {
     app.relaunch();
     app.quit();
   },
+  onLanguageChange: async (e, language: string) => {
+    // only works for win/linux
+    // see https://www.electronjs.org/docs/latest/tutorial/spellchecker#how-to-set-the-languages-the-spellchecker-uses
+    if (isMacOS()) {
+      return;
+    }
+
+    if (e.sender.session.availableSpellCheckerLanguages.includes(language)) {
+      e.sender.session.setSpellCheckerLanguages([language, 'en-US']);
+    }
+  },
 } satisfies NamespaceHandlers;