7ea802ab80
Replaces deprecated ai_client.send(md_content='', user_message=user_message, enable_tools=False) with ai_client.send_result(...) and branches on result.ok. On error, logs the ui_message() and returns [] (the function returns a list of track definitions or [] on failure). The 3 tests in test_orchestrator_pm.py + 1 in test_orchestrator_pm_history.py now fail because they mock src.ai_client.send. These will be fixed in Phase 2.14-2.15 by mocking send_result instead.