Add landing page, referral system, usage quotas, search API management, and yearly pricing

- Separate workspace landing from login for better UX
- Referral system rewards both parties with Pro days
- Quota enforcement prevents abuse without breaking endpoints
- 7-day free trial with auto-downgrade on expiry
- Admin-managed search provider config (SearXNG, Bing)
- 15% discount on annual subscriptions
- MCP search server wrapping opencode search
- Fix discovery module field name mismatch causing 422

admin-frontend/src/router/index.js

@@ -68,6 +68,14 @@ const routes = [
       { path: '', name: 'Invoices', component: () => import('@/views/Invoices.vue'), meta: { title: '发票管理' } },
     ]
   },
+  {
+    path: '/system/search-config',
+    component: AdminLayout,
+    meta: { requiresAuth: true },
+    children: [
+      { path: '', name: 'SearchConfig', component: () => import('@/views/SearchConfig.vue'), meta: { title: '搜索配置' } },
+    ]
+  },
 ]
 
 const router = createRouter({ history: createWebHistory('/admin/'), routes })