Adjust base colors (teal, blue, green, red, yellow, dimGray) to meet
4.5:1 contrast ratio against white backgrounds. Update thinking level
colors to reference theme vars for consistency.
Refactor test-theme-colors.ts into a CLI with contrast, test, and theme
commands for easier color validation.
Co-authored-by: Mario Zechner <badlogicgames@gmail.com>
* feat: add summarize extension example
Demonstrates custom UI with markdown rendering and external model
integration for conversation summarization.
* chore: update examples/extensions/README.md with summarize.ts
