fix(web): fechas de SAP con hora, enlaces como botones y un solo maestro de impuestos

Probado contra el SAP real (solo lectura): órdenes de venta y facturas de proveedor.

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

apps/web/src/app/features/documents/document-form.page.ts

@@ -30,9 +30,16 @@ import { ITEMS_MULTI_ADD, lineColumnsFor, newDocumentLine, recalcLine } from './
 const HEADER_KEYS = ['CardCode', 'NumAtCard', 'DocDate', 'DocDueDate', 'DiscountPercent', 'Comments'] as const;
 
 const today = (): string => new Date().toISOString().slice(0, 10);
+/** SAP devuelve las fechas como `2026-01-05T00:00:00Z`; el campo de fecha y el guardado usan `2026-01-05`. */
+const dateOnly = (v: unknown): string => (typeof v === 'string' ? v.slice(0, 10) : '');
 const pickHeader = (doc: DocRecord | undefined): DocRecord => {
   if (!doc) return { DocDate: today(), DocDueDate: today(), DiscountPercent: 0 };
-  return Object.fromEntries(HEADER_KEYS.map((k) => [k, doc[k] ?? (k === 'DiscountPercent' ? 0 : '')]));
+  return Object.fromEntries(
+    HEADER_KEYS.map((k) => [
+      k,
+      k === 'DocDate' || k === 'DocDueDate' ? dateOnly(doc[k]) : (doc[k] ?? (k === 'DiscountPercent' ? 0 : '')),
+    ]),
+  );
 };
 const text = (v: unknown): string => (v === null || v === undefined ? '' : String(v));