Fix unsafe property access and stale await in DurationInput, ModalAccountInfo, FilesPage

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/views/AccountManagement/ModalAccountInfo.vue

@@ -63,6 +63,6 @@ const is_active = computed(() => currentViewingUser.value.is_active);
 
 onBeforeMount(async () => {
   await acctMgmtStore.getUserDetail(currentViewingUser.value.username);
-  visitTime.value = currentViewingUser.value.detail.visits;
+  visitTime.value = currentViewingUser.value.detail?.visits ?? 0;
 });
 </script>