All previous hwmap changes were based on diagnosing exit code 8 as a
mapping failure, but the real cause was always build_opts. Now that
build_opts is removed, use the same VAAPI→OpenCL→reverse(VAAPI)→QSV
pattern that Jellyfin already uses for the doOclTonemap+isVaInVaOut
path instead of the unnecessary QSV intermediate.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>