- unsafe extern "C" blocks (Rust 2024 requirement) - unsafe blocks inside unsafe fn bodies - Use cudaMemGetInfo for accurate GPU memory reporting - Remove cc "cuda" feature (doesn't exist, built-in) - All 12 tests pass on RTX 5090 (CC 12.0, 170 SMs, 32GB) Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>