HEVC hardware decode times out now and then (nvd265 TIMEOUT), frames lost #2

Hardware HEVC decode on stock 2.3.7 sometimes stalls. In one AVPlayer run a 1080p HEVC clip delivered 18 of 120 frames, and the decoder logged:

nvd265: TIMEOUT: sem 2 want 3 GPGet 0 GPPut 3 cmdOff 0x600 pic 2 notifier 0 | status err 0 cycles 0 intra 0 inter 0 ctbpos 0

A VTDecompressionSession run of a 4K HEVC clip earlier the same evening returned 111 of 120 frames with 9 errors. Other runs of the same clips decode every frame (1080p about 820 fps, 4K about 250 fps), so the failure is intermittent.

Clips: 2 s at 60 fps, 8 Mbit/s, generated by probes/vtprobe.swift (AVAssetWriter). Playback check: probes/avplay.swift.

Tested on RTX 5070 Laptop (GB206, 10DE:2D18), Lenovo Legion 5 15IAX10, macOS 26.7.1 (25G241). Evidence: project-legion evidence/native/featuretest-2026-10-18/A/vid.play.txt, vid.vt.txt. The decoder is upstream's closed libnvdec_hevc.