🐛 Default classList to an array

src/store.js

@@ -46,7 +46,7 @@ export const changeDate = ref(new Date());
 export const timetable = ref({ trusted: true });
 export const substitutions = ref({});
 export const history = ref({});
-export const classList = ref({});
+export const classList = ref([]);
 
 /* API functions */
 // Set the `VITE_API_ENDPOINT` env variable when