Updated some underlying models

We've upgraded some of our underlying models to o3-mini, delivering significant improvements to Siena's capabilities.

This update brings:

— Enhanced reliability and consistency in responses

— More precise instruction following, even with less context provided (for example, you no longer have to write "IMPORTANT" for Siena to prioritize key information)

— Better handling of complex conversation flows

— Improved overall performance stability

You'll notice Siena is more dependable and accurate accomplishing tasks. Note that for complex tasks, responses may take slightly longer as Siena now takes time to process and think through solutions thoroughly.