- Updated create_mock_agent() to remove references to deleted methods (get_positions, get_last_trade, get_current_prices)
- Replaced position/holdings write tests with initial position creation test
- Added set_context AsyncMock to properly test async agent flow
- Skipped deprecated tests that verified removed _write_results_to_db() and _calculate_portfolio_value() methods
- All model_day_executor tests now pass (11 passed, 3 skipped)