Single-question campaign — make multi-planar libva accepted by VA-API
consumers on Rockchip hantro RK3568 (PineTab2/ohm first iteration).
Backend only, success criterion is boolean correctness, performance
deferred. Substrate carried over from libva-v4l2-request-fourier
STUDY.md (commit e0acc33 in the fork) plus locked decisions from the
2026-05-04 setup exchange.
Fork lives as a subdirectory: libva-v4l2-request-fourier/ (separate
git repo, origin marfrit/libva-v4l2-request-fourier, upstream
bootlin/libva-v4l2-request).
Empty Gitea repo created at git.reauktion.de/marfrit/libva-multiplanar;
local origin remote set, no push yet (per operator instruction —
wait for publish-worthy state).
