Fix CI: mirror upstream FleetDM image instead of docker build

No Dockerfile exists — this is a Helm chart project. Mirror the
upstream fleetdm/fleet image to the Gitea container registry,
tagged with both appVersion and chart version.

Co-authored-by: Cursor <cursoragent@cursor.com>

.github/workflows/release.yaml

@@ -121,16 +121,22 @@ jobs:
           mv fleetdm-stack-*.tgz .tmp/
           ls -la .tmp/
 
-      - name: Build and push container image
+      - name: Mirror FleetDM image to Gitea registry
         run: |
-          TAG="${{ steps.version.outputs.new_tag }}"
-          IMAGE="git.produktor.io/${{ gitea.repository }}/fleetdm-stack"
+          APP_VER=$(grep '^appVersion:' fleetdm-stack/Chart.yaml | awk '{print $2}' | tr -d '"')
+          CHART_TAG="${{ steps.version.outputs.new_tag }}"
+          SRC="fleetdm/fleet:v${APP_VER}"
+          DST="git.produktor.io/${{ gitea.repository }}/fleet"
 
           echo "${{ gitea.token }}" | docker login git.produktor.io -u "${{ gitea.actor }}" --password-stdin
-          docker build -t "${IMAGE}:${TAG}" -t "${IMAGE}:latest" .
-          docker push "${IMAGE}:${TAG}"
-          docker push "${IMAGE}:latest"
-          echo "Pushed ${IMAGE}:${TAG}"
+          docker pull "${SRC}"
+          docker tag "${SRC}" "${DST}:${APP_VER}"
+          docker tag "${SRC}" "${DST}:${CHART_TAG}"
+          docker tag "${SRC}" "${DST}:latest"
+          docker push "${DST}:${APP_VER}"
+          docker push "${DST}:${CHART_TAG}"
+          docker push "${DST}:latest"
+          echo "Mirrored ${SRC} → ${DST}:{${APP_VER},${CHART_TAG},latest}"
 
       - name: Create tag
         run: |