fix(ui): Toast 撤销可暂停，存储告警提升为全局

- Toast 自动关闭支持悬停/聚焦暂停，移开后按剩余时间继续
- 存储异常提示移到 App 级，看板与今日视图都能看到
- 归档隐藏与筛选隐藏分开说明，并提示列内排序暂停原因

src/components/ToastHost.vue

@@ -16,6 +16,10 @@ const { toasts } = storeToRefs(store)
       :key="toast.id"
       role="status"
       class="pointer-events-auto flex w-full max-w-sm items-center gap-3 rounded-md bg-slate-800 px-3 py-2 text-sm text-white shadow-panel dark:bg-zinc-100 dark:text-zinc-900"
+      @mouseenter="store.pause(toast.id)"
+      @mouseleave="store.resume(toast.id)"
+      @focusin="store.pause(toast.id)"
+      @focusout="store.resume(toast.id)"
     >
       <span class="min-w-0 flex-1 wrap-break-word">{{ toast.message }}</span>