Add apk downloader project based on aurora's core

Docker all in one

apk-downloader/Dockerfile

@@ -0,0 +1,26 @@
+# SPDX-FileCopyrightText: 2026 Aurora OSS
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+FROM eclipse-temurin:17-jdk AS build
+WORKDIR /workspace
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends git \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY . .
+RUN ./gradlew --no-daemon :apk-downloader:installDist
+
+FROM eclipse-temurin:17-jre
+WORKDIR /work
+
+COPY --from=build /workspace/apk-downloader/build/install/apk-downloader /opt/apk-downloader
+COPY apk-downloader/docker/download-apk /usr/local/bin/download-apk
+
+ENV PATH="/opt/apk-downloader/bin:${PATH}" \
+    APK_DOWNLOADS_DIR="/downloads"
+
+RUN mkdir -p /downloads \
+    && chmod +x /usr/local/bin/download-apk
+
+ENTRYPOINT ["/opt/apk-downloader/bin/apk-downloader"]