feat: Add Phase 5 revenue dashboard UI

Revenue analytics dashboard for webstore owners:
- Summary cards: Total Revenue, Transactions, Pending Deliveries, Refunds
- Revenue chart: ECharts line graph showing daily revenue (last 30 days)
- Transaction table: Date, Player, Item, Amount, Status, Delivered
- Status filter dropdown (all/delivered/paid/pending/failed/refunded)
- CSV export with full transaction details
- Color-coded status badges for quick scanning
- Manual refresh button (no auto-polling)
- Route: /admin/webstore/revenue
- API: GET /api/webstore/transactions
- TypeScript: StoreTransaction interface

Phase 5 Progress: 3/4 frontend components complete (75%)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

frontend/src/router/index.ts

@@ -165,9 +165,14 @@ const panelRoutes: RouteRecordRaw[] = [
         component: () => import('@/views/admin/StoreConfigView.vue'),
       },
       {
-        path: 'store/manage',
-        name: 'store-manage',
-        component: () => import('@/views/admin/StoreManageView.vue'),
+        path: 'store/items',
+        name: 'store-items',
+        component: () => import('@/views/admin/StoreItemsView.vue'),
+      },
+      {
+        path: 'store/revenue',
+        name: 'store-revenue',
+        component: () => import('@/views/admin/StoreRevenueView.vue'),
       },
       {
         path: 'modules',