task-90(店铺中心): 实现店铺分组选项加载

新增 shop-group-model.ts(ShopManageGroupItemVo 下拉项解析) 并在
shop-manage-api.ts 增加 fetchShopManageGroups(GET /api/admin/shop-manages/groups，
后端限定普通管理员可访问分组)。

TDD: task-90.test.ts 8 用例先 RED 后 GREEN。

admin-frontend-vue/src/pages/shop/shop-group-model.ts

@@ -0,0 +1,34 @@
+/** 店铺分组选项解析模型（任务 90）：解析 ShopManageGroupItemVo 数组为下拉选项，纯逻辑。 */
+import { unwrap } from '../../api/envelope.ts'
+import type { ShopGroupOption } from './shop-dto.ts'
+
+function text(value: unknown): string {
+  return typeof value === 'string' ? value.trim() : ''
+}
+
+function numberOrNull(value: unknown): number | null {
+  return typeof value === 'number' && Number.isFinite(value) ? Math.floor(value) : null
+}
+
+/** 解析单条分组下拉项；缺 id 视为无效。 */
+export function toShopGroupOption(raw: unknown): ShopGroupOption | null {
+  if (!raw || typeof raw !== 'object') return null
+  const record = raw as Record<string, unknown>
+  const id = numberOrNull(record.id)
+  if (id === null) return null
+  const option: ShopGroupOption = { id, groupName: text(record.groupName ?? record.group_name) }
+  const memberCount = numberOrNull(record.memberCount ?? record.member_count)
+  if (memberCount !== null) option.memberCount = memberCount
+  const leaderUsername = text(record.leaderUsername ?? record.leader_username)
+  if (leaderUsername) option.leaderUsername = leaderUsername
+  return option
+}
+
+/** 归一化分组下拉负载（信封或已解包数组）为选项列表；空/无效项过滤。 */
+export function parseShopManageGroups(payload: unknown): ShopGroupOption[] {
+  const data = unwrap<unknown>(payload)
+  if (!Array.isArray(data)) return []
+  return data
+    .map((raw) => toShopGroupOption(raw))
+    .filter((option): option is ShopGroupOption => option !== null)
+}

admin-frontend-vue/src/pages/shop/shop-manage-api.ts

@@ -1,9 +1,11 @@
-/** 店铺列表加载适配（任务 88）：GET /api/admin/shop-manages + 分页/筛选归一与解析。 */
+/** 店铺列表加载与分组选项适配（任务 88/90）：GET /api/admin/shop-manages(/groups) + 归一与解析。 */
 import { http } from '@/api/http'
 import { parseShopManagePage } from './shop-manage-model.ts'
+import { parseShopManageGroups } from './shop-group-model.ts'
 import {
   normalizeShopListParams,
   toShopManagePageQuery,
+  type ShopGroupOption,
   type ShopManageListParams,
   type ShopPageResult,
 } from './shop-dto.ts'
@@ -15,3 +17,11 @@ export async function fetchShopManageList(params: Partial<ShopManageListParams>
   const { data } = await http.get<unknown>(SHOP_MANAGE_ENDPOINT, { params: toShopManagePageQuery(normalized) })
   return parseShopManagePage(data)
 }
+
+export const SHOP_MANAGE_GROUPS_ENDPOINT = '/api/admin/shop-manages/groups'
+
+/** 加载店铺分组下拉选项（超级管理员取全部，普通管理员由后端限定可访问分组）。 */
+export async function fetchShopManageGroups(): Promise<ShopGroupOption[]> {
+  const { data } = await http.get<unknown>(SHOP_MANAGE_GROUPS_ENDPOINT)
+  return parseShopManageGroups(data)
+}