Initial Valheim dedicated server container with web UI scaffold

Dockerfile

@@ -0,0 +1,43 @@
+FROM debian:12-slim
+
+ENV DEBIAN_FRONTEND=noninteractive
+ENV VALHEIM_SERVER_DIR=/opt/valheim
+ENV STEAMCMD_DIR=/opt/steamcmd
+ENV USER=valheim
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+        ca-certificates \
+        curl \
+        wget \
+        jq \
+        lib32gcc-s1 \
+        tini \
+        procps \
+        iproute2 && \
+    rm -rf /var/lib/apt/lists/*
+
+# Create user
+RUN useradd -m -d /home/${USER} -s /bin/bash ${USER}
+
+# Create directories
+RUN mkdir -p ${VALHEIM_SERVER_DIR} ${STEAMCMD_DIR}
+RUN chown -R ${USER}:${USER} /opt /home/${USER}
+
+USER ${USER}
+
+# Install SteamCMD
+RUN cd ${STEAMCMD_DIR} && \
+    wget https://steamcdn-a.akamaihd.net/client/installer/steamcmd_linux.tar.gz && \
+    tar -xvzf steamcmd_linux.tar.gz && \
+    rm steamcmd_linux.tar.gz
+
+# Copy entrypoint
+COPY entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+
+EXPOSE 2456/udp 2457/udp 2458/udp
+EXPOSE 8080
+
+ENTRYPOINT ["/usr/bin/tini", "--"]
+CMD ["/entrypoint.sh"]