Render Studio Code interview options as small buttons

[sejas]

Related issues

• Fixes STU-1834

How AI was used in this PR

Proposed Changes

When the agent asks a multiple-choice question in the Studio Code tab, the answer options used to render as blue text links, so users didn't recognize them as choices waiting for a response — they read like hyperlinks rather than something to click.

This restyles those options as small buttons: a surface background with a border, padding, and rounded corners, with hover/focus feedback and no underline. The option the user picks fills with the accent color and stays clearly highlighted (and legible) even after the question is answered. The new styling uses Studio's dark-aware color tokens, so it works in both light and dark mode.

Testing Instructions

• Open the Studio Code tab and start an agent flow that asks the user a question with options (the AskUserQuestion tool).
• Confirm the options render as small buttons (not blue links), respond to hover/focus, and that the selected option stays highlighted after answering.
• Verify in both light and dark color schemes (macOS: System Settings → Appearance).

Before	After Light	After Dark

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[nightnei]

The idea is great.

I encountered only two things to clarify/fix:

1. Confirm ...., and that the selected option stays highlighted after answering. - after answering, I don't see the highlighted selected option. I looked into html and I don't see kinda "selected" classname. I don't think that it's critical thing, but woydl be good to have teh highlight, since it helps to read the history of selection inside the chat:
   
2. Also, I cought a case when it's selected once. It seems it's highlighted as selected only when it's temporary state - when it's necessary to select options from a few list at the same time. But the styles are broken for both Dark and Light theme. Example to reproduce it: