feat(dashboard): 增加极品专区与保险成交统计

- 仪表盘新增今日极品专区、保险8%、保险4%成交数量
- 展示近7日每日成交趋势和明细
- 按已支付订单口径统计，补充回归测试

frontend/src/features/admin/api/adminDashboard.ts

@@ -42,6 +42,20 @@ export interface ListingDailyOverview {
   timezone: string
 }
 
+export interface TradingDayStats {
+  date: string
+  premium_order_count: number
+  insurance_8_order_count: number
+  insurance_4_order_count: number
+}
+
+export interface TradingDailyOverview {
+  today: TradingDayStats
+  trend: TradingDayStats[]
+  days: number
+  timezone: string
+}
+
 export interface ListingUploaderDayStats {
   date: string
   uploader_id: number
@@ -82,6 +96,7 @@ export interface AdminDashboard {
   metrics: DashboardMetrics
   pending: DashboardPending
   listing_daily: ListingDailyOverview
+  trading_daily: TradingDailyOverview
   manual_entry_today: ManualEntryTodayStats[]
   recent_orders: DashboardRecentOrder[]
   recent_disputes: DashboardRecentDispute[]
@@ -95,10 +110,18 @@ const emptyDayStats = (): ListingDayStats => ({
   trade_leave_count: 0,
 })
 
+const emptyTradingDayStats = (): TradingDayStats => ({
+  date: '',
+  premium_order_count: 0,
+  insurance_8_order_count: 0,
+  insurance_4_order_count: 0,
+})
+
 export async function fetchAdminDashboard() {
   const { data } = await apiClient.get<ApiResponse<AdminDashboard>>('/admin/dashboard')
   const payload = data.data
   const listingDaily = payload.listing_daily
+  const tradingDaily = payload.trading_daily
   return {
     ...payload,
     listing_daily: {
@@ -111,6 +134,12 @@ export async function fetchAdminDashboard() {
       days: listingDaily?.days ?? 7,
       timezone: listingDaily?.timezone ?? 'Asia/Shanghai',
     },
+    trading_daily: {
+      today: tradingDaily?.today ?? emptyTradingDayStats(),
+      trend: tradingDaily?.trend ?? [],
+      days: tradingDaily?.days ?? 7,
+      timezone: tradingDaily?.timezone ?? 'Asia/Shanghai',
+    },
     manual_entry_today: payload.manual_entry_today ?? [],
     recent_orders: payload.recent_orders ?? [],
     recent_disputes: payload.recent_disputes ?? [],