diff --git a/.gitea/workflows/docker-publish.yml b/.gitea/workflows/docker-publish.yml
index 17f4b2c..cac4bca 100644
--- a/.gitea/workflows/docker-publish.yml
+++ b/.gitea/workflows/docker-publish.yml
@@ -1,5 +1,15 @@
 name: Reusable Docker Publish
 
+# Multi-arch (v1.9.0+): builds a manifest list for `platforms` (amd64 + arm64 by default) with
+# `docker buildx`, so the same tag runs on x86 servers and on the arm64 Raspberry Pi nodes with no
+# per-host changes. The Trivy gate is preserved by building the native amd64 image first with
+# --load, scanning that locally, and only then building + pushing the multi-arch manifest (the
+# amd64 layers are reused from cache, so only arm64 is newly built).
+#
+# Runner requirements (baked into the PipelineImage runner; the workflow also self-installs as a
+# fallback): the `docker buildx` plugin, and a build daemon that permits `--privileged` containers
+# so QEMU/binfmt can be registered for cross-building arm64 on an amd64 runner.
+
 on:
   workflow_call:
     inputs:
@@ -12,6 +22,11 @@ on:
       floating_tag:
         type: string
         default: "edge"
+      platforms:
+        # target platforms for the manifest list. Override to a single platform (e.g.
+        # "linux/amd64") for images that do not need to run on the arm64 nodes.
+        type: string
+        default: "linux/amd64,linux/arm64"
       run_image_scan:
         type: boolean
         default: true
@@ -34,6 +49,17 @@ on:
       NTFY_SERVER: { required: true }
       PIP_EXTRA_INDEX_URL: { required: false }
 
+# Pinned build tooling. Keep in sync with the ARGs in the PipelineImage Dockerfiles.
+# buildx: verify the binary against checksums.txt from the buildx GitHub release before bumping.
+# binfmt: pin by digest (tonistiigi/binfmt@sha256:...) for the strongest posture; the version tag
+# below is immutable enough for CI and avoids a Docker Hub token dance in the workflow.
+env:
+  BUILDX_VERSION: "0.35.0"
+  BUILDX_SHA256: "d41ece72044243b4f58b343441ae37446d9c29a7d6b5e11c61847bbcf8f7dfda"
+  BINFMT_IMAGE: "tonistiigi/binfmt:qemu-v10.2.3"
+  TRIVY_VERSION: "0.71.0"
+  TRIVY_SHA256: "30a3d22b23f88c233f1658f562fb477cae3b3e8b4761109d515b7698daf85814"
+
 jobs:
   publish:
     runs-on: docker
@@ -51,36 +77,70 @@ jobs:
         id: vars
         shell: bash
         run: |
+          set -euo pipefail
           SHA_SHORT="$(git rev-parse --short HEAD)"
           FULL_IMAGE="${{ secrets.DOCKER_REGISTRY }}/${{ inputs.image_name }}"
-          TAGS="-t ${FULL_IMAGE}:${SHA_SHORT}"
-          
+
+          # the SHA tag is always built; it is also the target Trivy scans before any push
+          PUSH_TAGS="-t ${FULL_IMAGE}:${SHA_SHORT} -t ${FULL_IMAGE}:${{ inputs.floating_tag }}"
+
           if echo "${{ gitea.ref }}" | grep -q '^refs/tags/v'; then
             VERSION="${{ gitea.ref_name }}"
             VERSION="${VERSION#v}"
             MAJOR="$(echo "$VERSION" | cut -d. -f1)"
             MINOR="$(echo "$VERSION" | cut -d. -f1,2)"
-            TAGS="${TAGS} -t ${FULL_IMAGE}:latest -t ${FULL_IMAGE}:${VERSION} -t ${FULL_IMAGE}:${MINOR} -t ${FULL_IMAGE}:${MAJOR}"
+            PUSH_TAGS="${PUSH_TAGS} -t ${FULL_IMAGE}:latest -t ${FULL_IMAGE}:${VERSION} -t ${FULL_IMAGE}:${MINOR} -t ${FULL_IMAGE}:${MAJOR}"
           fi
-          
-          echo "docker_tags=${TAGS}" >> "$GITEA_OUTPUT"
+
+          echo "scan_ref=${FULL_IMAGE}:${SHA_SHORT}" >> "$GITEA_OUTPUT"
+          echo "push_tags=${PUSH_TAGS}" >> "$GITEA_OUTPUT"
           echo "full_image=${FULL_IMAGE}" >> "$GITEA_OUTPUT"
 
       - name: Docker Login
         run: |
           echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login "${{ secrets.DOCKER_REGISTRY }}" -u "${{ secrets.REGISTRY_USERNAME }}" --password-stdin
 
-      - name: Build image
+      - name: Set up Docker Buildx and QEMU
+        shell: bash
+        env:
+          PLATFORMS: ${{ inputs.platforms }}
+        run: |
+          set -euo pipefail
+
+          # Ensure the buildx plugin. Baked into the runner image (PipelineImage); this fallback
+          # covers older runners, mirroring the Trivy fallback below. Pinned + checksum-verified.
+          if ! docker buildx version >/dev/null 2>&1; then
+            echo "=== buildx not in runner image, installing v${BUILDX_VERSION} ==="
+            mkdir -p /usr/libexec/docker/cli-plugins
+            curl -sSfLo /usr/libexec/docker/cli-plugins/docker-buildx \
+              "https://github.com/docker/buildx/releases/download/v${BUILDX_VERSION}/buildx-v${BUILDX_VERSION}.linux-amd64"
+            echo "${BUILDX_SHA256}  /usr/libexec/docker/cli-plugins/docker-buildx" | sha256sum -c -
+            chmod +x /usr/libexec/docker/cli-plugins/docker-buildx
+          fi
+          docker buildx version
+
+          # Register QEMU so this amd64 runner can cross-build the non-native platforms. binfmt is
+          # a kernel concern, so it cannot live in the runner image and is installed here against
+          # the build daemon (needs --privileged).
+          if echo "${PLATFORMS}" | grep -q 'arm'; then
+            echo "=== Registering QEMU emulators (${BINFMT_IMAGE}) ==="
+            docker run --privileged --rm "${BINFMT_IMAGE}" --install arm64
+          fi
+
+          # A docker-container builder is required for multi-platform output (the default docker
+          # driver builds a single platform only). Idempotent across re-runs on a warm runner.
+          docker buildx inspect multiarch >/dev/null 2>&1 || \
+            docker buildx create --name multiarch --driver docker-container --bootstrap
+          docker buildx use multiarch
+
+      - name: Build image for vulnerability scan
+        if: ${{ inputs.run_image_scan }}
         shell: bash
         env:
           PIP_EXTRA_INDEX_URL: ${{ secrets.PIP_EXTRA_INDEX_URL }}
         run: |
           set -euo pipefail
-          SHA_SHORT="$(git rev-parse --short HEAD)"
-          FULL_IMAGE="${{ secrets.DOCKER_REGISTRY }}/${{ inputs.image_name }}"
 
-          # optionally hand the private package index to the build as a BuildKit secret so the
-          # Dockerfile can install the in-house BB* packages without the token entering a layer
           SECRET_ARGS=""
           if [ "${{ inputs.use_private_index }}" = "true" ]; then
             if [ -z "${PIP_EXTRA_INDEX_URL:-}" ]; then
@@ -90,28 +150,17 @@ jobs:
             SECRET_ARGS="--secret id=pip_extra_index,env=PIP_EXTRA_INDEX_URL"
           fi
 
-          DOCKER_BUILDKIT=1 docker build \
+          # native amd64 only, loaded into the local image store so Trivy can scan it before
+          # anything is pushed. The amd64 result is cached and reused by the multi-arch push.
+          # CVEs live in the base image and OS/Python packages, which are identical across arches,
+          # so scanning amd64 is a faithful gate for the whole manifest list.
+          DOCKER_BUILDKIT=1 docker buildx build \
+            --load \
+            --platform linux/amd64 \
             ${SECRET_ARGS} \
-            -t "${FULL_IMAGE}:${SHA_SHORT}" \
+            -t "${{ steps.vars.outputs.scan_ref }}" \
             ${{ inputs.dockerfile_path }}
 
-          # Floating tag points at the most recent build on any branch/tag, so
-          # the nightly image-security scan always has a stable target even
-          # before a release exists. ":latest" stays release-only (below).
-          docker tag "${FULL_IMAGE}:${SHA_SHORT}" "${FULL_IMAGE}:${{ inputs.floating_tag }}"
-
-          if echo "${{ gitea.ref }}" | grep -q '^refs/tags/v'; then
-            VERSION="${{ gitea.ref_name }}"
-            VERSION="${VERSION#v}"
-            MAJOR="$(echo "$VERSION" | cut -d. -f1)"
-            MINOR="$(echo "$VERSION" | cut -d. -f1,2)"
-
-            docker tag "${FULL_IMAGE}:${SHA_SHORT}" "${FULL_IMAGE}:latest"
-            docker tag "${FULL_IMAGE}:${SHA_SHORT}" "${FULL_IMAGE}:${VERSION}"
-            docker tag "${FULL_IMAGE}:${SHA_SHORT}" "${FULL_IMAGE}:${MINOR}"
-            docker tag "${FULL_IMAGE}:${SHA_SHORT}" "${FULL_IMAGE}:${MAJOR}"
-          fi
-
       - name: Image Vulnerability Scan
         if: ${{ inputs.run_image_scan }}
         shell: bash
@@ -122,8 +171,6 @@ jobs:
           # checksum, never "latest": Trivy releases were compromised in the
           # March 2026 supply-chain incident (malicious v0.69.4). Keep in sync
           # with the ARGs in the PipelineImage Dockerfiles.
-          TRIVY_VERSION=0.71.0
-          TRIVY_SHA256=30a3d22b23f88c233f1658f562fb477cae3b3e8b4761109d515b7698daf85814
           if ! command -v trivy >/dev/null 2>&1; then
             echo "=== Trivy not in runner image, installing v${TRIVY_VERSION} ==="
             curl -sSfLO "https://github.com/aquasecurity/trivy/releases/download/v${TRIVY_VERSION}/trivy_${TRIVY_VERSION}_Linux-64bit.tar.gz"
@@ -133,74 +180,49 @@ jobs:
           fi
           trivy --version
 
-          SHA_SHORT="$(git rev-parse --short HEAD)"
-          FULL_IMAGE="${{ secrets.DOCKER_REGISTRY }}/${{ inputs.image_name }}"
-
-          echo "=== Scanning ${FULL_IMAGE}:${SHA_SHORT} (fail on fixable ${{ inputs.scan_severity }}) ==="
+          echo "=== Scanning ${{ steps.vars.outputs.scan_ref }} (fail on fixable ${{ inputs.scan_severity }}) ==="
           trivy image \
             --exit-code 1 \
             --severity "${{ inputs.scan_severity }}" \
             --ignore-unfixed \
             --scanners vuln,secret \
-            "${FULL_IMAGE}:${SHA_SHORT}"
+            "${{ steps.vars.outputs.scan_ref }}"
 
-      - name: Push image
+      - name: Build and push multi-arch image
         shell: bash
+        env:
+          PIP_EXTRA_INDEX_URL: ${{ secrets.PIP_EXTRA_INDEX_URL }}
         run: |
           set -euxo pipefail
 
           echo "=== Git / Ref Info ==="
           git rev-parse HEAD
-          git rev-parse --short HEAD
           echo "gitea.ref=${{ gitea.ref }}"
           echo "gitea.ref_name=${{ gitea.ref_name }}"
+          echo "platforms=${{ inputs.platforms }}"
 
-          SHA_SHORT="$(git rev-parse --short HEAD)"
-          FULL_IMAGE="${{ secrets.DOCKER_REGISTRY }}/${{ inputs.image_name }}"
+          SECRET_ARGS=""
+          if [ "${{ inputs.use_private_index }}" = "true" ]; then
+            if [ -z "${PIP_EXTRA_INDEX_URL:-}" ]; then
+              echo "use_private_index=true but the PIP_EXTRA_INDEX_URL secret is empty or not set"
+              exit 1
+            fi
+            SECRET_ARGS="--secret id=pip_extra_index,env=PIP_EXTRA_INDEX_URL"
+          fi
 
-          echo "=== Image Info ==="
-          echo "FULL_IMAGE=${FULL_IMAGE}"
-          echo "SHA_SHORT=${SHA_SHORT}"
-          echo "Expected image: ${FULL_IMAGE}:${SHA_SHORT}"
+          # one build produces every platform and pushes a manifest list per tag. The Trivy gate
+          # above already ran on the amd64 image these layers are reused from, so a scan failure
+          # aborts the job before this step. On a version tag this also pushes latest/major/minor.
+          DOCKER_BUILDKIT=1 docker buildx build \
+            --push \
+            --platform "${{ inputs.platforms }}" \
+            ${SECRET_ARGS} \
+            ${{ steps.vars.outputs.push_tags }} \
+            ${{ inputs.dockerfile_path }}
 
-          echo "=== Local Docker Images ==="
-          docker images | grep "${{ inputs.image_name }}" || true
-
-          echo "=== Inspect Image ==="
-          docker image inspect "${FULL_IMAGE}:${SHA_SHORT}" >/dev/null
-
-          echo "=== Docker Auth Check ==="
-          docker info
-
-          echo "=== Push SHA tag ==="
-          docker push "${FULL_IMAGE}:${SHA_SHORT}"
-
-          echo "=== Push floating tag (${{ inputs.floating_tag }}) ==="
-          docker push "${FULL_IMAGE}:${{ inputs.floating_tag }}"
-
-          if echo "${{ gitea.ref }}" | grep -q '^refs/tags/v'; then
-            echo "=== Version tag detected ==="
-
-            VERSION="${{ gitea.ref_name }}"
-            VERSION="${VERSION#v}"
-            MAJOR="$(echo "$VERSION" | cut -d. -f1)"
-            MINOR="$(echo "$VERSION" | cut -d. -f1,2)"
-
-            echo "VERSION=${VERSION}"
-            echo "MINOR=${MINOR}"
-            echo "MAJOR=${MAJOR}"
-
-            echo "=== Push latest ==="
-            docker push "${FULL_IMAGE}:latest"
-
-            echo "=== Push version ==="
-            docker push "${FULL_IMAGE}:${VERSION}"
-
-            echo "=== Push minor ==="
-            docker push "${FULL_IMAGE}:${MINOR}"
-
-            echo "=== Push major ==="
-            docker push "${FULL_IMAGE}:${MAJOR}"
-          else
-            echo "=== No version tag detected, only SHA tag pushed ==="
-          fi
\ No newline at end of file
+      - name: Verify pushed manifest
+        shell: bash
+        run: |
+          set -euo pipefail
+          # confirm the pushed tag really is a multi-arch manifest list
+          docker buildx imagetools inspect "${{ steps.vars.outputs.scan_ref }}"