feat: redondeo en el pie de los documentos de ventas y compras (visible según OADM.RoundMthd) y endpoint /api/company/settings

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

apps/web/src/app/features/documents/document-layouts.ts

@@ -44,6 +44,8 @@ export type HeaderField =
   /** Flete: código del gasto adicional y su importe (`DocumentAdditionalExpenses`). */
   /** Tabla de gastos adicionales del documento (flete, seguro…): una fila por gasto. */
   | { type: 'expenses'; label: string }
+  /** Redondeo del documento (`Rounding` y `RoundingDiffAmount`): solo se ofrece si la empresa usa redondeo (`OADM.RoundMthd`). */
+  | { type: 'rounding'; label: string }
   | { type: 'computed'; label: string; source: ComputedSource };
 
 /** Las listas de valores (ventanas modales) de un formulario. */
@@ -263,11 +265,12 @@ export function marketingLayout(opts: {
         { type: 'number', key: 'DiscountPercent', label: 'Descuento %', decimals: 2 },
         { type: 'computed', label: 'Gastos adicionales', source: 'expenses' },
         { type: 'computed', label: 'Impuesto', source: 'tax' },
+        { type: 'rounding', label: 'Redondeo' },
         { type: 'computed', label: 'Total del documento', source: 'total' },
       ],
     },
     columns,
-    newHeader: () => ({ DocType: ITEMS_DOC_TYPE, DocDate: today(), DocDueDate: today(), DiscountPercent: 0 }),
+    newHeader: () => ({ DocType: ITEMS_DOC_TYPE, DocDate: today(), DocDueDate: today(), DiscountPercent: 0, Rounding: 'tNO', RoundingDiffAmount: 0 }),
     newLine: newDocumentLine,
     recalc: recalcLine,
     service: {
@@ -301,6 +304,8 @@ export const keysOfFields = (fields: readonly HeaderField[]): string[] =>
         return [f.prefixKey, f.numberKey];
       case 'expenses':
         return [];
+      case 'rounding':
+        return ['Rounding', 'RoundingDiffAmount'];
       default:
         return [f.key];
     }