Force cudarc's is_managing_stream_synchronization() to false.
Eliminates ALL internal event tracking (cuStreamSynchronize,
cuEventRecord, cuStreamWaitEvent) that was adding 18.7 syncs/step.
All stream synchronization is managed manually via raw_launch events.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
f1093e9a07