feat(item): add delete functionality

This commit introduces the ability to delete items. A new `ItemDeleteModal` component provides a confirmation step
before removal.

- Adds a 'Delete' option to the action menu in the items table.
- Refactors the `useItems` composable to ensure reactivity with `useLocalStorage` by creating new array references on
add/remove operations.
- Renames `AddModal` to `EditModal` to better align with its future role in both adding and editing items.

app/layouts/default.vue

@@ -36,7 +36,7 @@ const items = computed<NavigationMenuItem[]>(() => [
   {
     label: "物品管理",
     to: "/",
-    icon: "marketeq:home-alt-3",
+    icon: "marketeq:box",
   },
   {
     label: "导出配置",