As I recall, artifical intelligences aren't sentient enough to have true personalities (i.e. be suitable as player characters).
They can manifest physically by myriads of nanobots forming a shape such as a driver or guide. But that would still just be a "puppet" of the AI.
No robots (other than what we call industrial robots today) and no androids (the rules do allow for cybernetic implants and bionic sculpts).
The impression I got was that all of these limitations are by choice - to make the setting different.
Not having AIs in human forms be perfect helps immensely in maintaining the human-centric focus, both in general and in the way starship combat focuses on human skill.
Having "construct" AI be decidedly servile makes them "djinn-like". Having their bodies consist of nanobots makes them shapeshifters. It's the Sci Fi equivalence of magical spirits that live in bottles!