fix: address copilot review comments

Author: javorosas

src/main/java/io/facturapi/models/complements/pago/PagoComplementData.java

@@ -16,15 +16,25 @@ public class PagoComplementData {
   private List<PaymentRelatedDocument> relatedDocuments = new ArrayList<>();
   private String currency;
   private Double exchange;
+  @JsonProperty("num_operacion")
   private String numOperacion;
+  @JsonProperty("rfc_emisor_cta_ord")
   private String rfcEmisorCtaOrd;
+  @JsonProperty("nom_banco_ord_ext")
   private String nomBancoOrdExt;
+  @JsonProperty("cta_ordenante")
   private String ctaOrdenante;
+  @JsonProperty("rfc_emisor_cta_ben")
   private String rfcEmisorCtaBen;
+  @JsonProperty("cta_beneficiario")
   private String ctaBeneficiario;
+  @JsonProperty("tipo_cad_pago")
   private String tipoCadPago;
+  @JsonProperty("cert_pago")
   private String certPago;
+  @JsonProperty("cad_pago")
   private String cadPago;
+  @JsonProperty("sello_pago")
   private String selloPago;
 
   public PaymentForm getPaymentForm() { return paymentForm; }

src/test/java/io/facturapi/StubHttpClient.java

@@ -10,6 +10,7 @@
 import java.net.http.HttpHeaders;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
+import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.nio.ByteBuffer;
 import java.util.ArrayDeque;
@@ -42,7 +43,9 @@ static final class QueuedResponse {
   private final List<HttpRequest> requests = new ArrayList<>();
 
   void enqueueJson(int statusCode, String json) {
-    queue.add(new QueuedResponse(statusCode, json.getBytes(), Map.of("Content-Type", List.of("application/json"))));
+    queue.add(
+      new QueuedResponse(statusCode, json.getBytes(StandardCharsets.UTF_8), Map.of("Content-Type", List.of("application/json")))
+    );
   }
 
   void enqueueBinary(int statusCode, byte[] bytes, String contentType) {