Prevent Steam startup hangups and persist profile path.

Launch Steam via nohup under steam user and enforce stable ~/.steam symlink for reboot-safe startup.

Co-authored-by: Cursor <cursoragent@cursor.com>

Dockerfile

@@ -33,6 +33,7 @@ RUN echo '#!/bin/bash\n\
 rm -f /tmp/.X99-lock /tmp/.X11-unix/X99\n\
 id steam >/dev/null 2>&1 || useradd -m -s /bin/bash steam\n\
 mkdir -p /home/steam/.local/share/Steam /tmp/xdg-steam\n\
+ln -sfn /home/steam/.local/share/Steam /home/steam/.steam\n\
 chown -R steam:steam /home/steam /tmp/xdg-steam\n\
 Xvfb :99 -ac -screen 0 1920x1080x24 &\n\
 export DISPLAY=:99\n\