Store supported AI models in SQLite instead of code

[brainless]

As a user I would like updated list of the AI models that are supported, including latest versions and costs. Right now list of models is in Rust code and this should be moved into SQLite DB which can sync from an online list (on https://dwata.com).

As the list of supported models and AI providers increase, and many providers support using OpenAI compatible API, we can also add support for new models without changing code.

[brainless]

We should also store features per AI model and/or model so it is easy to surface these capabilities through the API.

[brainless]

Features would include:

• function calling
• embedding

[brainless]

I decided not to store model information in SQLite since the code to work with models will anyhow need to be written and perhaps it is practical to build feature or model list from API calls or Rust code.