Embedded Assistant does not inherit site-level Suggested questions

Bug description

When using the React embedded Assistant, if no suggestions prop is passed to <GitBookFrame />, the Assistant shows AI-generated suggested questions instead of the "Suggested questions" configured in Customization → AI Assistant.

Expected behavior:

The embedded Assistant should fall back to the site-level Suggested questions when embed-level suggestions are not provided.

Actual behavior:

The embedded Assistant displays AI-generated questions unless suggestions is explicitly set in code.

Environment:

React embed using <GitBookFrame /> with tabs={['assistant']} and no suggestions prop.

Impact:

This creates inconsistent behavior between the docs site Assistant and the embedded Assistant, and forces duplication of question lists.