The gateway emits agent events with stream='lifecycle' and data.phase
('start'/'end'/'error'), but ControlChannel.swift was looking for
stream='job' and data.state ('started'/'streaming'/etc).
This mismatch caused the menu bar to always show 'Idle' even when the
agent was actively working.
Changes:
- ControlChannel.swift: Handle 'lifecycle' stream instead of 'job',
map phase values to the states WorkActivityStore expects
- AgentEventsWindow.swift: Update stream color mapping for consistency
Fixes#1932
