refactor(frontend): scripts -> utility

packages/frontend/src/stream.ts

@@ -8,7 +8,7 @@ import { markRaw } from 'vue';
 import { $i } from '@/account.js';
 import { wsOrigin } from '@@/js/config.js';
 // TODO: No WebsocketモードでStreamMockが使えそう
-//import { StreamMock } from '@/scripts/stream-mock.js';
+//import { StreamMock } from '@/utility/stream-mock.js';
 
 // heart beat interval in ms
 const HEART_BEAT_INTERVAL = 1000 * 60;