UE5 writes Saved/running.dat as a "session in progress" marker. If
the previous session exited uncleanly (SIGKILL, crash), it lingers,
and SN2 pops up an invisible 0×0 Error dialog at next launch that
the GameThread blocks on forever — visible only as a black screen
with a spinning loader. Wrap the Steam command to clear the marker
files before each launch.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Lets Subnautica 2 (and any other game) opt into the GE-Proton
build via Steam's per-game compatibility tool override, as a
workaround for the Proton Experimental + DXVK D3D12 Mercuna hang.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Move Steam config from configuration.nix to a dedicated gaming.nix module
and add gamescope for fullscreen/resolution management with Proton games.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
