The previous commit removed disable_event_tracking() from graph capture,
causing CUDA_ERROR_STREAM_CAPTURE_INVALIDATED on H100 (events recorded
during capture invalidate the capture).
Fix: disable event tracking BEFORE begin_capture, re-enable AFTER end_capture.
With GPU-native cat/stack (no to_host roundtrip), the re-enable is now safe —
post-capture operations don't call to_host on graph-modified buffers.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>