refactor(frontend): use ESM

packages/frontend/src/theme-store.ts

@@ -3,10 +3,10 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { Theme } from './scripts/theme';
-import { miLocalStorage } from './local-storage';
-import { api } from '@/os';
-import { $i } from '@/account';
+import { Theme } from '@/scripts/theme.js';
+import { miLocalStorage } from '@/local-storage.js';
+import { api } from '@/os.js';
+import { $i } from '@/account.js';
 
 const lsCacheKey = $i ? `themes:${$i.id}` as const : null;