fix: don't show export ready message when no export exists

The API returns an empty object {} with 200 status when no export
exists. This truthy value was being set as exportInfo, causing the
"ready for download" message and button to render with a blank date.

frontend/src/views/user/settings/DataExport.vue

@@ -93,7 +93,7 @@ const formattedExpiresDate = computed(() => exportInfo.value ? formatDisplayDate
 onMounted(async () => {
 	try {
 		const data = await dataExportService.status()
-		exportInfo.value = data
+		exportInfo.value = data?.id ? data : null
 	} catch {
 		exportInfo.value = null
 	}