Before this, a Windows user setting COLI_CUDA=0 for a CPU baseline silently got a ~12.6 GB VRAM expert tier anyway: the bare-run auto-enable ran before any env check, so every Windows 'CPU' benchmark row taken this way was actually GPU-assisted (found while building the 12-cell resource matrix in #467). Setting COLI_GPU=none instead collided with auto-enable's COLI_GPUS ('use COLI_GPU or COLI_GPUS, not both', exit 2). Now an explicit COLI_CUDA=0 suppresses auto-enable and clears stale device/sizing vars, same as --gpu none, which stays the canonical hard off-switch. Docs: COLI_CUDA row updated; DIRECT row + README get the measured, drive-dependent O_DIRECT guidance (+34 decode on real NVMe w/ DRAM cache; neutral-to-negative on QLC/DRAM-less).
Mohamed Mastouri
f939191404