embed steam Half-Life data into the image itself

allows also adding hlsdk libs to the image
makes it easier to build, manage, and run

container/Containerfile.hlsdk

@@ -0,0 +1,48 @@
+FROM ubuntu:24.04
+
+# This cannot reference external dirs, unfortunately
+ARG HALFLIFE_STEAM_FILES=./Half-Life
+
+# Copy HL data files
+RUN mkdir -p /opt/hl && chown ubuntu:ubuntu /opt/hl
+COPY --chown=ubuntu:ubuntu ${HALFLIFE_STEAM_FILES}/valve /opt/hl/valve
+COPY --chown=ubuntu:ubuntu ${HALFLIFE_STEAM_FILES}/valve_hd /opt/hl/valve_hd
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+# Install generic build dependencies
+RUN apt-get update && apt-get install --no-install-recommends --no-install-suggests -y \
+    \
+    # Build essential utilities
+    ca-certificates \
+    wget \
+    build-essential \
+    pkg-config \
+    python3 \
+    git
+
+# Build FWGS hlsdk game libs
+ARG FWGS_HLSDK_REF=ae84bfc0c3598fcff605a7b3bb963abe8ec3e295
+RUN mkdir -p /build && chown ubuntu:ubuntu /build
+USER ubuntu
+RUN cd /build && \
+    git version && \
+    # git > 2.49: git clone --depth 1 --revision ${FWGS_HLSDK_REF} https://github.com/FWGS/hlsdk-portable && \
+    mkdir -p hlsdk-portable && \
+    cd hlsdk-portable && \
+    git init && \
+    git remote add origin https://github.com/FWGS/hlsdk-portable && \
+    git fetch --depth 1 origin ${FWGS_HLSDK_REF} && \
+    git checkout FETCH_HEAD && \
+    ./waf \
+        configure -8 -T release \
+        build \
+        install --destdir=/opt/hl
+
+# Cleanup build files
+RUN rm -rf /build/hlsdk-portable
+
+# At this point there's:
+# /opt/hl with
+#   ./valve
+#       {dlls, cl_dlls} with fwgs/hlsdk libs