curl -X GET '/crypto-gateway/overview' \
  -H 'Authorization: Bearer YOUR_ACCESS_TOKEN'

{
  "success": true,
  "data": {
    "total_payments": 150,
    "total_volume_usd": 25000.00,
    "paid_count": 120,
    "pending_count": 10,
    "expired_count": 20,
    "conversion_rate": "80%"
  }
}