feat: Add billing routes in server.js for retrieving and updating billing data, and integrate BillingManager in App.jsx for navigation

frontend/src/App.jsx

@@ -27,6 +27,7 @@ import DomainsNewManager from './DomainsNewManager';
 import IPRangesManager from './IPRangesManager';
 import ASNsNewManager from './ASNsNewManager';
 import AutoUrlManager from './AutoUrlManager';
+import BillingManager from './BillingManager';
 import './App.css';
 import axios from 'axios';
 import {
@@ -60,6 +61,7 @@ function MainLayout() {
     { id: 'asns', title: 'AS', icon: IconNetwork, path: '/asns' },
     { id: 'auto-urls', title: 'Авто URL', icon: IconDownload, path: '/auto-urls' },
     { id: 'servers', title: 'Серверы', icon: IconServer, path: '/servers' },
+    { id: 'billing', title: 'Биллинг', icon: IconCreditCard, path: '/billing' },
     { id: 'filters', title: 'Фильтры', icon: IconFilter, path: '/filters' },
     { id: 'files', title: 'Файлы', icon: IconFileText, path: '/files' },
     { id: 'cloud', title: 'Облако', icon: IconCloud, path: '/cloud' },
@@ -108,6 +110,7 @@ function MainLayout() {
           <Route path="/asns" element={<ASNsNewManager />} />
           <Route path="/auto-urls" element={<AutoUrlManager />} />
           <Route path="/servers" element={<ServerManager />} />
+          <Route path="/billing" element={<BillingManager />} />
           <Route path="/filters" element={<FilterManager />} />
           <Route path="/" element={<Navigate to="/domains" replace />} />
         </Routes>