fix: avoid not-found redirect for timeslot episode editor

We need to wait for the timeslot to be updated before routing to the
editor page, because otherwise the editor page might redirect back to
the overview because it can’t find the episode for the timeslot.

src/components/shows/TimeSlotRow.vue

@@ -161,7 +161,8 @@ const hasEnded = computed(() => now.value > end.value)
 const { create: createEpisode, isSaving: isCreatingEpisode } = useCreateBehaviour(
   async function () {
     const episode = await episodeStore.create({ showId: props.timeslot.showId })
-    episodeId.value = episode.id
+    // We don’t set episodeId.value here, because we need to know when the change has been persisted.
+    await timeslotStore.partialUpdate(props.timeslot.id, { episodeId: episode.id })
     await router.push({
       name: 'show-timeslot-details',
       params: { timeslotId: props.timeslot.id },