fix: ESM compatibility - avoid direct Response object mutation

templates/base/http-clients/fetch-http-client.ejs

@@ -196,9 +196,29 @@ export class HttpClient<SecurityDataType = unknown> {
             body: typeof body === "undefined" || body === null ? null : payloadFormatter(body),
         }
         ).then(async (response) => {
-            const r = response as HttpResponse<T, E>;
-            r.data = (null as unknown) as T;
-            r.error = (null as unknown) as E;
+            // Create a wrapper object that doesn't mutate the Response
+            // This ensures compatibility with ESM environments where Response is read-only
+            const r = {
+                data: (null as unknown) as T,
+                error: (null as unknown) as E,
+                // Delegate Response properties
+                ok: response.ok,
+                status: response.status,
+                statusText: response.statusText,
+                headers: response.headers,
+                url: response.url,
+                redirected: response.redirected,
+                type: response.type,
+                body: response.body,
+                bodyUsed: response.bodyUsed,
+                // Delegate Response methods
+                arrayBuffer: () => response.arrayBuffer(),
+                blob: () => response.blob(),
+                clone: () => response.clone(),
+                formData: () => response.formData(),
+                json: () => response.json(),
+                text: () => response.text(),
+            } as HttpResponse<T, E>;
 
             const responseToParse = responseFormat ? response.clone() : response;
             const data = !responseFormat ? r : await responseToParse[responseFormat]()