feat: add Solana USDT/USDC support and refine admin payouts UI

app/admin/layout.tsx

@@ -16,7 +16,8 @@ import {
     ChevronDown,
     Wallet,
     Building2,
-    Code2
+    Code2,
+    ArrowUpRight
 } from 'lucide-react';
 
 export default function AdminLayout({
@@ -35,6 +36,7 @@ export default function AdminLayout({
     const navItems = [
         { label: 'Genel Bakış', icon: LayoutDashboard, href: '/admin' },
         { label: 'Firmalar', icon: Building2, href: '/admin/merchants' },
+        { label: 'Ödemeler', icon: ArrowUpRight, href: '/admin/payouts' },
         { label: 'İşlemler', icon: CreditCard, href: '/admin/transactions' },
         { label: 'Müşteriler', icon: Users, href: '/admin/customers' },
         { label: 'Analizler', icon: BarChart3, href: '/admin/analytics' },