feat(web): ver documentos cancelados y sus documentos de cancelación (filtro, estado y botón para ir de uno al otro)

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

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

@@ -82,6 +82,9 @@
     <button sboActions class="btn" type="button" (click)="reload()">Recargar</button>
   }
   <a sboActions class="btn" routerLink="..">{{ readOnly() ? 'Cerrar' : 'Cancelar' }}</a>
+  @if (cancellation(); as c) {
+    <button sboActions class="btn" type="button" (click)="openCancellationPair()">{{ c === 'cancelled' ? 'Ver su cancelación' : 'Ver el documento cancelado' }}</button>
+  }
   @if (copyFromItems().length) {
     <sbo-menu-button sboActionsEnd label="Copiar de" [items]="copyFromItems()" (picked)="copyFrom($event)" />
   }