feat: migrate payment provider to easy-pay, add order history and refund support

- Replace zpay with easy-pay payment provider (new lib/easy-pay/ module)
- Add order history page for users (pay/orders)
- Add GET /api/orders/my endpoint to list user's own orders
- Add GET /api/users/[id] endpoint for sub2api user lookup
- Add order status tracking module (lib/order/status.ts)
- Update config to support easy-pay credentials (merchant ID, key, gateway)
- Update PaymentForm and PaymentQRCode components for easy-pay flow
- Update pay page and admin page with new order management UI
- Update order service to support easy-pay, cancellation, and refund

src/components/OrderStatus.tsx

@@ -0,0 +1,68 @@
+'use client';
+
+interface OrderStatusProps {
+  status: string;
+  onBack: () => void;
+}
+
+const STATUS_CONFIG: Record<string, { label: string; color: string; icon: string; message: string }> = {
+  COMPLETED: {
+    label: '充值成功',
+    color: 'text-green-600',
+    icon: '✓',
+    message: '余额已到账，感谢您的充值！',
+  },
+  PAID: {
+    label: '充值中',
+    color: 'text-blue-600',
+    icon: '⟳',
+    message: '支付成功，正在充值余额中...',
+  },
+  RECHARGING: {
+    label: '充值中',
+    color: 'text-blue-600',
+    icon: '⟳',
+    message: '正在充值余额中，请稍候...',
+  },
+  FAILED: {
+    label: '充值失败',
+    color: 'text-red-600',
+    icon: '✗',
+    message: '充值失败，请联系管理员处理。',
+  },
+  EXPIRED: {
+    label: '订单超时',
+    color: 'text-gray-500',
+    icon: '⏰',
+    message: '订单已超时，请重新创建订单。',
+  },
+  CANCELLED: {
+    label: '已取消',
+    color: 'text-gray-500',
+    icon: '✗',
+    message: '订单已取消。',
+  },
+};
+
+export default function OrderStatus({ status, onBack }: OrderStatusProps) {
+  const config = STATUS_CONFIG[status] || {
+    label: status,
+    color: 'text-gray-600',
+    icon: '?',
+    message: '未知状态',
+  };
+
+  return (
+    <div className="flex flex-col items-center space-y-4 py-8">
+      <div className={`text-6xl ${config.color}`}>{config.icon}</div>
+      <h2 className={`text-xl font-bold ${config.color}`}>{config.label}</h2>
+      <p className="text-center text-gray-500">{config.message}</p>
+      <button
+        onClick={onBack}
+        className="mt-4 w-full rounded-lg bg-blue-600 py-3 font-medium text-white hover:bg-blue-700"
+      >
+        {status === 'COMPLETED' ? '完成' : '返回充值'}
+      </button>
+    </div>
+  );
+}