Add Manyfold add-on integration

manyfold/Dockerfile

@@ -0,0 +1,27 @@
+ARG BUILD_FROM=ghcr.io/manyfold3d/manyfold-solo:latest
+FROM ${BUILD_FROM}
+
+# hadolint ignore=DL3041
+RUN set -eux; \
+    if command -v apk >/dev/null 2>&1; then \
+      apk add --no-cache bash coreutils jq openssl; \
+    elif command -v apt-get >/dev/null 2>&1; then \
+      apt-get update; \
+      apt-get install -y --no-install-recommends bash coreutils jq openssl ca-certificates; \
+      rm -rf /var/lib/apt/lists/*; \
+    elif command -v dnf >/dev/null 2>&1; then \
+      dnf install -y bash coreutils jq openssl; \
+      dnf clean all; \
+    else \
+      echo "Unsupported base image: missing apk/apt-get/dnf"; \
+      exit 1; \
+    fi
+
+COPY run.sh /run.sh
+COPY rootfs /
+
+RUN chmod +x /run.sh \
+    && chmod +x /etc/s6-overlay/s6-rc.d/manyfold/run \
+    && chmod +x /etc/s6-overlay/s6-rc.d/manyfold/finish
+
+ENTRYPOINT ["/init"]