fix(groups): 用户分组不下发内部路由信息

- 普通用户 Group DTO 移除 model_routing/account_count/account_groups，避免泄露内部路由与账号信息\n- 新增 AdminGroup DTO，并仅在管理员分组接口返回完整字段\n- 前端拆分 Group/AdminGroup，管理端页面与 API 使用 AdminGroup\n- 增加 /api/v1/groups/available 契约测试，防止回归

frontend/src/views/admin/AccountsView.vue

@@ -187,14 +187,14 @@ import AccountCapacityCell from '@/components/account/AccountCapacityCell.vue'
 import PlatformTypeBadge from '@/components/common/PlatformTypeBadge.vue'
 import Icon from '@/components/icons/Icon.vue'
 import { formatDateTime, formatRelativeTime } from '@/utils/format'
-import type { Account, Proxy, Group } from '@/types'
+import type { Account, Proxy, AdminGroup } from '@/types'
 
 const { t } = useI18n()
 const appStore = useAppStore()
 const authStore = useAuthStore()
 
 const proxies = ref<Proxy[]>([])
-const groups = ref<Group[]>([])
+const groups = ref<AdminGroup[]>([])
 const selIds = ref<number[]>([])
 const showCreate = ref(false)
 const showEdit = ref(false)

frontend/src/views/admin/GroupsView.vue

@@ -1107,7 +1107,7 @@ import { useI18n } from 'vue-i18n'
 import { useAppStore } from '@/stores/app'
 import { useOnboardingStore } from '@/stores/onboarding'
 import { adminAPI } from '@/api/admin'
-import type { Group, GroupPlatform, SubscriptionType } from '@/types'
+import type { AdminGroup, GroupPlatform, SubscriptionType } from '@/types'
 import type { Column } from '@/components/common/types'
 import AppLayout from '@/components/layout/AppLayout.vue'
 import TablePageLayout from '@/components/layout/TablePageLayout.vue'
@@ -1202,7 +1202,7 @@ const fallbackGroupOptionsForEdit = computed(() => {
   return options
 })
 
-const groups = ref<Group[]>([])
+const groups = ref<AdminGroup[]>([])
 const loading = ref(false)
 const searchQuery = ref('')
 const filters = reactive({
@@ -1223,8 +1223,8 @@ const showCreateModal = ref(false)
 const showEditModal = ref(false)
 const showDeleteDialog = ref(false)
 const submitting = ref(false)
-const editingGroup = ref<Group | null>(null)
-const deletingGroup = ref<Group | null>(null)
+const editingGroup = ref<AdminGroup | null>(null)
+const deletingGroup = ref<AdminGroup | null>(null)
 
 const createForm = reactive({
   name: '',
@@ -1529,7 +1529,7 @@ const handleCreateGroup = async () => {
   }
 }
 
-const handleEdit = async (group: Group) => {
+const handleEdit = async (group: AdminGroup) => {
   editingGroup.value = group
   editForm.name = group.name
   editForm.description = group.description || ''
@@ -1585,7 +1585,7 @@ const handleUpdateGroup = async () => {
   }
 }
 
-const handleDelete = (group: Group) => {
+const handleDelete = (group: AdminGroup) => {
   deletingGroup.value = group
   showDeleteDialog.value = true
 }