Proper way of writing a HQL in ( ... ) query
I am unsure how to do this with positional parameter, but if you can use named parameters instead of positional, then named parameter can be placed inside brackets and setParameterList method from Query interface can be used to bind the list of values to this parameter.
...
Query query = session.createQuery("FROM Cat c WHERE c.id IN (:ids)");
query.setParameterList("ids", listOfIds);
...
Older versions of Hibernate may not have the setParameterList method on Query. You can still call setParameter("ids", listOfIds); on the older one for the same effect.