curl --request GET \
  --url https://api.contazen.ro/v1/clients/{id} \
  --header 'Authorization: Bearer <token>'

{
  "success": true,
  "data": {
    "id": "cli_1a2b3c4d5e",
    "object": "client",
    "name": "<string>",
    "email": "jsmith@example.com",
    "phone": "<string>",
    "cui": "<string>",
    "cui_prefix": "<string>",
    "rc": "<string>",
    "address": "<string>",
    "city": "<string>",
    "county": "<string>",
    "country": "<string>",
    "postal_code": "<string>",
    "iban": "<string>",
    "bank": "<string>",
    "contact_person": "<string>",
    "created_at": 123,
    "updated_at": 123,
    "metadata": {
      "invoices_count": 123,
      "total_invoiced": 123,
      "unpaid_total": 123
    },
    "stats": {
      "total_invoiced": 123,
      "total_collected": 123,
      "avg_payment_days": 123,
      "last_payment": {
        "date": 123,
        "amount": 123,
        "currency": "<string>",
        "bill_id": "<string>",
        "bill_number": "<string>"
      },
      "monthly_series": [
        {
          "label": "Mar 2026",
          "year": 123,
          "month": 123,
          "invoiced": 123,
          "collected": 123
        }
      ]
    }
  },
  "meta": {
    "version": "v1",
    "request_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "response_time": "23.45ms"
  }
}