grep -q quits at the first match, gamescope then dies on the broken pipe, and with
pipefail a working build counted as broken (intermittent: the generic build was
tried and failed too, gaming mode setup failed on an RTX 5080). Output goes to a
file now and timeout -k kills a hung shutdown.
The conversion installs the patched gamescope on every NVIDIA PC and sets up the kernel parameters, suspend memory and 32-bit libraries on a supported card; it turns off an existing Gaming on NVIDIA.
The conversion also sets up what Gaming on NVIDIA did there (kernel parameters, early modules, suspend memory, 32-bit libraries). Gaming on NVIDIA is only offered on older NVIDIA cards, or while it is on.
The conversion is offered on supported NVIDIA cards again; it builds and installs steamify-gamescope-nvidia and sets gamescope_drm_gbm_scanout=1. It and Gaming on NVIDIA exclude each other.