- Add step callback to AgentRunner for real-time step logging
- BenchmarkUI now shows:
- Active runs with current step info
- Recent steps panel with colored config prefixes
- Proper Live display refresh (implements __rich_console__)
- Each config gets a distinct color for easy identification
- Verbose mode prints step logs immediately with config prefix
- Fix Live display not updating (pass UI object, not rendered content)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>