🐛 Correctly copy objects

- Fixes timetable data corruption on timetable group change

src/store.js

@@ -155,7 +155,7 @@ export const parsedTimetable = computed(() => {
   return timetable.value.data.map((day) => {
     const parsedDay = [];
     for (const lesson of day) {
-      let usedLesson = lesson;
+      let usedLesson = { ...lesson };
       // Check if lesson has multiple options
       // (timetable groups)
       if (Array.isArray(lesson)) {
@@ -171,7 +171,7 @@ export const parsedTimetable = computed(() => {
             length: lesson[0].length || 1,
           };
         }
-        usedLesson = matchingLesson;
+        usedLesson = { ...matchingLesson };
       }
       // Duplicate the lesson if its length is > 1 for it
       // to show up multiple times in the timetable view