fix: properly export io in ES modules wrapper

The syntax was invalid:

```
export const io = io;
             ^

SyntaxError: Identifier 'io' has already been declared
    at Loader.moduleStrategy (internal/modules/esm/translators.js:122:18)
```

wrapper.mjs

@@ -1,5 +1,5 @@
 import io from "./build/index.js";
 
 export const Manager = io.Manager;
-export const io = io;
+export { io };
 export default io;