feat(web): add getCfdiXml API function

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/web/lib/api/cfdi.ts

@@ -89,3 +89,10 @@ export async function createManyCfdis(
 export async function deleteCfdi(id: string): Promise<void> {
   await apiClient.delete(`/cfdi/${id}`);
 }
+
+export async function getCfdiXml(id: string): Promise<string> {
+  const response = await apiClient.get<string>(`/cfdi/${id}/xml`, {
+    responseType: 'text'
+  });
+  return response.data;
+}