feat(后台分组): 分组筛选与分组列仅超管可见，非超管一律隐藏

管理员/普通用户数据已由后端裁剪到本人可访问分组，分组维度对其无意义；
账号归属分组是超管职责，故只有超管需要按分组筛选与区分。

- 隐藏分组筛选+分组列：品牌数据库、查询ASIN、最低价ASIN、去重总数据、
  店铺管理、用户密钥
- 仅隐藏分组展示：店铺数据记录(筛选框+卡片行)、图片视频任务(所属分组行)、
  撞款检测(明细抽屉分组列+卡片分组标签)
- 弹窗分组选择保留展示但锁定：非超管仅1个可访问分组时自动选中并置灰
  (查询/最低价ASIN 另联动加载该分组店铺)，多分组不锁以免限制用户
- 空数据行 colspan 随列显隐动态化
- 新增 tests/align-group-visibility.test.ts 回归守卫(5 条)

admin-frontend-vue/src/pages/shop/ShopManagePage.vue

@@ -18,6 +18,8 @@ import type { ShopCredential, ShopGroupOption, ShopSummary } from './shop-dto.ts
 import OldPagination from '@/components/OldPagination.vue'
 
 const session = useAdminSessionStore()
+/** 仅超管需要分组维度：非超管数据由后端裁剪到本人分组，分组筛选/列一律不展示。 */
+const isSuperAdmin = computed(() => session.isSuperAdmin)
 const loading = ref(false)
 const rows = ref<ShopSummary[]>([])
 const total = ref(0)
@@ -42,6 +44,11 @@ const revealedPasswordCache = ref<Record<number, string>>({})
 const revealedRowId = ref<number | null>(null)
 
 const groupOptions = computed(() => groups.value)
+/** 非超管仅有一个可访问分组时，弹窗分组选择锁定为该组（保留展示、不可改）。 */
+const lockedGroupId = computed<number | null>(() => {
+  if (isSuperAdmin.value) return null
+  return groups.value.length === 1 ? groups.value[0].id : null
+})
 
 function shownPassword(row: ShopSummary): string {
   if (revealedRowId.value !== row.id) return row.passwordMasked || '******'
@@ -123,13 +130,14 @@ function goJump() {
 function openCreate() {
   editingId.value = null
   Object.assign(form, emptyShopManageForm())
+  if (lockedGroupId.value != null) form.groupId = lockedGroupId.value
   dialogVisible.value = true
 }
 
 function openEdit(row: ShopSummary) {
   editingId.value = row.id
   Object.assign(form, {
-    groupId: row.groupId,
+    groupId: row.groupId ?? lockedGroupId.value,
     shopName: row.shopName,
     mallName: row.mallName,
     znUsername: row.znUsername,
@@ -214,7 +222,7 @@ onMounted(() => {
       </div>
 
       <div class="form-row shop-filter-row">
-        <div class="form-group" style="min-width: 180px">
+        <div v-if="isSuperAdmin" class="form-group" style="min-width: 180px">
           <label>分组</label>
           <el-select v-model="filter.groupId" class="admin-filter" filterable clearable placeholder="全部分组">
             <el-option v-for="group in groupOptions" :key="group.id" :label="group.groupName" :value="group.id" />
@@ -232,7 +240,7 @@ onMounted(() => {
           <thead>
             <tr>
               <th style="width: 58px">序号</th>
-              <th style="width: 120px">分组</th>
+              <th v-if="isSuperAdmin" style="width: 120px">分组</th>
               <th style="width: 150px">店铺名</th>
               <th style="width: 130px">店铺商城名</th>
               <th style="width: 130px">自动化账号</th>
@@ -247,7 +255,7 @@ onMounted(() => {
             <template v-if="rows.length">
               <tr v-for="(row, index) in rows" :key="row.id">
                 <td>{{ (page - 1) * pageSize + index + 1 }}</td>
-                <td data-text :title="row.groupName || '—'">{{ row.groupName || '—' }}</td>
+                <td v-if="isSuperAdmin" data-text :title="row.groupName || '—'">{{ row.groupName || '—' }}</td>
                 <td :title="row.shopName">{{ row.shopName }}</td>
                 <td :title="row.mallName || '—'">{{ row.mallName || '—' }}</td>
                 <td :title="row.znUsername || '—'">{{ row.znUsername || '—' }}</td>
@@ -273,10 +281,10 @@ onMounted(() => {
               </tr>
             </template>
             <tr v-else-if="loading">
-              <td colspan="10" class="empty-tip">加载中...</td>
+              <td :colspan="isSuperAdmin ? 10 : 9" class="empty-tip">加载中...</td>
             </tr>
             <tr v-else>
-              <td colspan="10" class="empty-tip">暂无店铺</td>
+              <td :colspan="isSuperAdmin ? 10 : 9" class="empty-tip">暂无店铺</td>
             </tr>
           </tbody>
         </table>
@@ -287,7 +295,7 @@ onMounted(() => {
     <el-dialog v-model="dialogVisible" :title="editingId == null ? '新增店铺' : '编辑店铺'" width="600px">
       <el-form label-width="120px">
         <el-form-item label="所属分组" required>
-          <el-select filterable v-model="form.groupId" placeholder="选择分组">
+          <el-select filterable v-model="form.groupId" placeholder="选择分组" :disabled="lockedGroupId != null">
             <el-option v-for="group in groupOptions" :key="group.id" :label="group.groupName" :value="group.id" />
           </el-select>
         </el-form-item>
@@ -316,7 +324,7 @@ onMounted(() => {
     <el-dialog v-model="credentialVisible" title="店铺明文凭据" width="560px">
       <el-descriptions v-if="credential" :column="1" border>
         <el-descriptions-item label="店铺名">{{ credential.shopName }}</el-descriptions-item>
-        <el-descriptions-item label="分组">{{ credential.groupName || '—' }}</el-descriptions-item>
+        <el-descriptions-item v-if="isSuperAdmin" label="分组">{{ credential.groupName || '—' }}</el-descriptions-item>
         <el-descriptions-item label="店铺商城名">{{ credential.mallName || '—' }}</el-descriptions-item>
         <el-descriptions-item label="账号">{{ credential.account }}</el-descriptions-item>
         <el-descriptions-item label="密码">