Modernize AI Assistant Side Chat UI with Icon-Based Controls

[Blaec-CoCalc]

Is your feature request related to a problem? Please describe.
In the AI Assistant's side chat UI on CoCalc, controls like "regenerate," "reply," "summarize," and "fold" appear as prominent text labels. This creates a cluttered appearance, making the side panel feel busy and less visually appealing compared to modern chat interfaces (such as Gemini), which rely on compact, icon-based controls.

Describe the solution you'd like
Update the side chat UI by replacing text labels with intuitive icons for actions (regenerate, reply, summarize, fold, etc.). Include tooltips for accessibility. This would streamline the side chat's look, making it cleaner and more in line with contemporary chat tools.

Additional context
A more minimalist, icon-driven side chat will provide an improved, modern experience for users and set clearer expectations for usability, especially as side chat is the primary interface for most AI Assistant interactions.

Gemini Example:

[williamstein]

Please suggest specific icons here that would work: https://cocalc.com/features/icons

We can also add any icons from https://www.iconfont.cn/?lang=en-us to the icons available at the above link...