Fix an error in fetch.ts (probably the source of these build issues)

src/backend/helpers/fetch.ts

@@ -69,7 +69,12 @@ export async function singularProxiedFetch<T>(
     onResponse(context) {
       const tokenHeader = context.response.headers.get("X-Token");
       if (tokenHeader) setApiToken(tokenHeader);
-      ops.onResponse?.(context);
+
+      if (Array.isArray(ops.onResponse)) {
+        ops.onResponse.forEach((hook) => hook(context));
+      } else {
+        ops.onResponse?.(context);
+      }
     },
   });
 }