feat: add formats endpoint and update factura handler

- Add GET /api/v1/formats to list available formats
- Simplify HandleFacturas to accept raw JSON (format auto-detected)
- Remove format query param handling

api/handler.go

@@ -12,6 +12,7 @@ import (
 	"VerifactuMidAPI/internal/cert"
 	"VerifactuMidAPI/internal/config"
 	"VerifactuMidAPI/internal/crypto"
+	"VerifactuMidAPI/internal/formats"
 )
 
 type RegisterInput struct {
@@ -178,17 +179,7 @@ func (h *Handler) HandleFacturas(w http.ResponseWriter, r *http.Request) {
 
 	log.Printf("facturas request: %s", string(body))
 
-	var input internal.AltaInput
-	if err := json.Unmarshal(body, &input); err != nil {
-		log.Printf("json unmarshal error: %v", err)
-		w.Header().Set("Content-Type", "application/json")
-		w.Write([]byte(`{"success":false,"error":"invalid_json"}`))
-		return
-	}
-
-	log.Printf("facturas input:%+v", input)
-
-	output, _ := h.facturaSvc.ProcessAlta(input)
+	output, _ := h.facturaSvc.ProcessAlta(body)
 
 	log.Printf("facturas output:%+v", output)
 
@@ -222,3 +213,17 @@ func (h *Handler) HandleFacturasAnular(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
 	w.Write(resp)
 }
+
+func (h *Handler) ListFormats(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	available := formats.Available()
+	resp, _ := json.Marshal(map[string]interface{}{
+		"formats": available,
+	})
+	w.Header().Set("Content-Type", "application/json")
+	w.Write(resp)
+}

api/router.go

@@ -9,6 +9,7 @@ func (h *Handler) RegisterRoutes(mux *http.ServeMux) {
 	mux.HandleFunc("/api/v1/auth/register", h.RegisterCert)
 	mux.HandleFunc("/api/v1/facturas", h.HandleFacturas)
 	mux.HandleFunc("/api/v1/facturas/anular", h.HandleFacturasAnular)
+	mux.HandleFunc("/api/v1/formats", h.ListFormats)
 	mux.HandleFunc("/api/v1/health", h.HealthCheck)
 }