Stabilize Steam startup and persistent user data in containers.

Run Steam Big Picture as dedicated steam user with persistent home-backed storage and document first-run bootstrap behavior.

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

Dockerfile

@@ -7,7 +7,7 @@ ENV DEBIAN_FRONTEND=noninteractive
 RUN dpkg --add-architecture i386 && \
     apt-get update && apt-get install -y \
     xvfb fluxbox dbus-x11 xauth xfonts-base x11-xserver-utils \
-    software-properties-common wget curl ca-certificates \
+    software-properties-common wget curl ca-certificates locales pciutils \
     libcap2-bin libgomp1 mesa-utils \
     libxcb-cursor0 libxcb-xinerama0 libxcb-xfixes0 libxcb-shape0 libxcb-randr0 libxcb-xtest0 \
     libxcb1 libxcb-render0 libxcb-render-util0 libxcb-util1 libxcb-keysyms1 \
@@ -23,6 +23,7 @@ RUN wget "https://github.com/LizardByte/Sunshine/releases/download/v0.21.0/sunsh
 RUN apt-get update && \
     echo "debconf steam/question select I AGREE" | debconf-set-selections \
     && apt-get install -y /tmp/sunshine.deb steam:i386 steam-devices \
+    && locale-gen en_US.UTF-8 \
     && rm -f /tmp/sunshine.deb \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*
@@ -30,9 +31,14 @@ RUN apt-get update && \
 # 4. Скрипт очищает сессию, поднимает виртуальный экран, fluxbox и запускает Sunshine
 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\
+chown -R steam:steam /home/steam /tmp/xdg-steam\n\
 Xvfb :99 -ac -screen 0 1920x1080x24 &\n\
 export DISPLAY=:99\n\
 export HOME=/root\n\
+export LANG=en_US.UTF-8\n\
+export LC_ALL=en_US.UTF-8\n\
 sleep 3\n\
 fluxbox &\n\
 sleep 2\n\