Add a new performance test suite to simulate terminal scrolling and diagnose reported UI lag (indicated by eventloopDelay spikes) and high CPU usage. Make event loop monitoring opt-in to avoid overhead in production.
- Make EventLoopMonitor opt-in via GEMINI_EVENT_LOOP_MONITOR_ENABLED.
- Support passing custom environment variables to the child process in TestRig.
- Add CPU utilization percentage to the PerfTestHarness report.
- Inject child process event loop metrics into performance snapshots.
- Add a matrix of scrolling tests across different buffer configurations.
Sri Pasumarthi