Add admin port support with other major refactorations

docker/Dockerfile

@@ -0,0 +1,60 @@
+# Build stage
+FROM debian:bookworm AS builder
+
+RUN apt-get update && apt-get install -y \
+    build-essential \
+    cmake \
+    git \
+    libcurl4-gnutls-dev \
+    liblzma-dev \
+    liblzo2-dev \
+    libpng-dev \
+    libzstd-dev \
+    zlib1g-dev \
+    pkg-config \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /src
+COPY OpenTTD-patches /src/OpenTTD-patches
+
+WORKDIR /src/OpenTTD-patches/build
+RUN cmake .. \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DOPTION_DEDICATED=ON \
+    -DOPTION_INSTALL_HTML_DOCS=OFF \
+    -DOPTION_USE_ASSERTS=OFF \
+    && make -j$(nproc) install
+
+# Runtime stage
+FROM debian:bookworm-slim
+
+RUN apt-get update && apt-get install -y \
+    libcurl3-gnutls \
+    liblzma5 \
+    liblzo2-2 \
+    libpng16-16 \
+    libzstd1 \
+    zlib1g \
+    ca-certificates \
+    openttd-opengfx \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy binaries from builder
+COPY --from=builder /usr/local/games/openttd /usr/local/bin/openttd
+COPY --from=builder /usr/local/share/games/openttd /usr/local/share/games/openttd
+
+# Ensure base graphics are in a path openttd searches
+RUN mkdir -p /usr/local/share/games/openttd/baseset && \
+    cp -r /usr/share/games/openttd/baseset/* /usr/local/share/games/openttd/baseset/
+
+# Create openttd user
+RUN useradd -m -u 1000 openttd
+USER openttd
+WORKDIR /home/openttd
+
+# Create config directory
+RUN mkdir -p /home/openttd/.local/share/openttd/save
+
+EXPOSE 3979/tcp 3979/udp 3977/tcp
+
+CMD ["openttd", "-D"]