Problem: EnumWindows was iterating through ALL windows on system
when EU wasn't running, causing 4.5s blocking delays every 5s.
Changes:
- _find_window_by_title: 100ms timeout, 500 window limit
- _find_window_by_process: 150ms timeout, 300 window limit
- Skip empty window titles (performance)
- Slow down focus detection to 60s when EU not found 3x
This should eliminate the 2s menu + 7s click delays.