- Add backtest proto definitions with selector and state types
- Update domain types for backtest session and configuration
- Implement backtest selector flow for data range input
- Add CLI operator client and handoff test coverage
- Update generated code for proto changes
- Add worker socket backtest mapping implementations
- Include agent-task for milestone tracking
- Implement backtest workflow validation for headless operator mode
- Add handoff evidence tracking for backtest runs
- Update operator client, runner, scenario, and output modules
- Add test files for handoff, backtest runner, and error handling
- Add test data for backtest scenarios and validation
