feat(item): implement item editing functionality

This commit introduces the capability to edit existing items. The `ItemEditModal` has been refactored to support both creation and editing modes.

- The modal UI (title, buttons) and submission logic now adapt based on whether an item is being added or edited.
- A new `editItem` function is added to the `useItemsStore` to handle the update logic.
- Form validation for the item name is enhanced to correctly check for uniqueness during edits.
- The table's row action menu now opens the modal in edit mode, pre-populating the form.
- The `latestId` generation logic is improved for robustness.
- Additionally, this commit adds row selection checkboxes to the items table.

app/composables/items.ts

@@ -42,9 +42,11 @@ const _useItems = () => {
           item.createdAt.getFullYear() === thisYear
       ).length;
     }),
-    latestId: computed(
-      () => (items.value?.[items.value.length - 1]?.id ?? 0) + 1
-    ),
+    latestId: computed(() => {
+      const arr = items.value ?? [];
+      if (arr.length === 0) return 1;
+      return Math.max(...arr.map((i) => i.id)) + 1;
+    }),
   };
 
   const isNameAvailable = (name: string) =>
@@ -54,11 +56,26 @@ const _useItems = () => {
     items.value = [...(items.value ?? []), item]; // <-- 替换数组引用
   };
 
+  const editItem = (item: Item) => {
+    const index = (items.value ?? []).findIndex((i) => i.id === item.id);
+    if (index === -1) return; // 未找到则直接返回
+
+    // 生成一个新的数组（保持响应式）
+    const updatedItems = [...(items.value ?? [])];
+    updatedItems[index] = {
+      ...updatedItems[index],
+      ...item,
+      updatedAt: new Date(), // 自动更新时间戳
+    };
+
+    items.value = updatedItems; // 替换引用，触发 UI 更新
+  };
+
   const removeItem = (id: number) => {
     items.value = (items.value ?? []).filter((i) => i.id !== id); // <-- 替换数组引用
   };
 
-  return { items, stats, isNameAvailable, addItem, removeItem };
+  return { items, stats, isNameAvailable, addItem, editItem, removeItem };
 };
 
 export const useItemsStore = createSharedComposable(_useItems);