feat(facturacion): precio unitario sin IVA en conceptos

- Cambia label de 'Precio Unitario (IVA incluido)' a 'Precio Unitario (sin IVA)'
- Elimina división interna price/(1+iva) en calcConcepto; ahora price es la base
- Cambia taxIncluded: true → false en payload enviado a backend
- Backend: tax_included default false en facturapi.service.ts y
  contribuyente-facturapi.service.ts
- Build y deploy exitosos

apps/web/app/(dashboard)/facturacion/page.tsx

@@ -611,8 +611,7 @@ export default function FacturacionPage() {
   // Cálculos
   function calcConcepto(c: ConceptoForm) {
     const trasladoRates = c.taxes.filter(t => t.category === 'traslado' && t.factor === 'Tasa').reduce((s, t) => s + t.rate, 0);
-    const unitPrice = trasladoRates > 0 ? c.price / (1 + trasladoRates) : c.price;
-    const base = unitPrice * c.quantity - c.discount;
+    const base = c.price * c.quantity - c.discount;
     const traslados = c.taxes.filter(t => t.category === 'traslado' && t.factor === 'Tasa').reduce((s, t) => s + base * t.rate, 0);
     const retenciones = c.taxes.filter(t => t.category === 'retencion').reduce((s, t) => s + base * t.rate, 0);
     return { base, traslados, retenciones };
@@ -688,7 +687,7 @@ export default function FacturacionPage() {
         quantity: c.quantity,
         price: tipoComprobante === 'T' ? 0 : c.price,
         discount: c.discount || 0,
-        taxIncluded: true,
+        taxIncluded: false,
         objetoImp: c.objetoImp,
         taxes: tipoComprobante === 'T' || c.objetoImp === '01' ? [] : c.taxes.map(t => ({
           type: t.type,
@@ -1437,7 +1436,7 @@ export default function FacturacionPage() {
                       {tipoComprobante !== 'T' && (
                         <>
                           <div className="space-y-2">
-                            <Label>Precio Unitario (IVA incluido)</Label>
+                            <Label>Precio Unitario (sin IVA)</Label>
                             <Input type="number" min="0" step="0.01" value={c.price || ''} onChange={e => updateConcepto(idx, 'price', parseFloat(e.target.value) || 0)} placeholder="0.00" required />
                           </div>
                           <div className="space-y-2">