Support permissions for models (and possibly tools/assistants)

[zacps]

Describe your feature request

We are considering using chat-ui for our own custom LLM tools. Because we want complete control over the generation we're currently implementing these as models. However, some of these tools will have access to documents that are not broadly available within the company. Because of this we want to be able to restrict model access by user.

Implementation idea

• Retrieve groups via OIDC
• Add an alllowed_groups field to each model
• Restrict usage & visibility of each model by group membership

We're currently working on implementing this in our private fork, but I wanted to reach out to ask @nsarrazin if a patch would be accepted upstream, and if there would be any additional requirements.

[nsarrazin]

I think that would be a great addition! We would definitely accept a patch for this as long as it's not a breaking change, which should be doable 😄