curl -X POST '/unified-transactions/export' \
  -H 'Authorization: Bearer YOUR_ACCESS_TOKEN' \
  -H 'Content-Type: application/json' \
  -d '{
    "format": "pdf",
    "date_from": "2026-03-01",
    "date_to": "2026-03-31",
    "types": ["deposit", "withdrawal", "swap"]
  }'

{
  "success": true,
  "data": {
    "export_id": "exp_01abc123",
    "format": "pdf",
    "status": "processing",
    "filters": {
      "date_from": "2026-03-01",
      "date_to": "2026-03-31",
      "types": ["deposit", "withdrawal", "swap"]
    },
    "created_at": "2026-04-01T12:00:00Z"
  }
}