DefaultHasher (SipHash) uses random per-process keys — the PTX cache would never hit across separate cargo test runs. Switch to SHA-256 (deterministic) so cached PTX persists on the PVC across CI runs. Also extend activeDeadlineSeconds from 90min to 120min to accommodate the one-time cold-start NVRTC compilation (30+ min for the fused experience collector kernel). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>