Enable custom headers in query requests

Uncommented the spread of config.customHeader in the request headers, allowing custom headers to be included in outgoing POST requests.

src/lib/query.ts

@@ -337,7 +337,7 @@ async function query(
               "User-Agent":
                 "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36 Edg/141.0.0.0",
               // ...fingerprint,
-              // ...config?.customHeader,
+              ...config?.customHeader,
             },
             method: "POST",
             body: requestBody,