- Add CallRecord dataclass for tracking call history
- Extend Session with call_history, active_real_caller, ai_respond_mode, auto_followup
- Add get_show_history() for AI caller context about earlier calls
- Update get_conversation_summary() to handle host/real_caller/ai_caller roles
- Update reset() to clear new fields
- Add tests for all new functionality
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>