ci(helm): publish chart to ghcr oci on release tags

.github/workflows/docker-publish.yml

@@ -44,3 +44,34 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
+
+  publish-chart:
+    name: Package & push Helm chart to GHCR
+    runs-on: ubuntu-latest
+    needs: [publish]
+    if: startsWith(github.ref, 'refs/tags/')
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: azure/setup-helm@v4
+
+      - name: Derive chart version
+        id: version
+        run: echo "VERSION=${GITHUB_REF_NAME#v}" >> "$GITHUB_OUTPUT"
+
+      - name: Log in to GHCR (Helm OCI)
+        run: |
+          echo "${{ secrets.GITHUB_TOKEN }}" | helm registry login ghcr.io \
+            --username "${{ github.actor }}" \
+            --password-stdin
+
+      - name: Package chart
+        run: |
+          helm package charts/openconcho \
+            --version "${{ steps.version.outputs.VERSION }}" \
+            --app-version "${{ steps.version.outputs.VERSION }}"
+
+      - name: Push chart
+        run: |
+          helm push "openconcho-${{ steps.version.outputs.VERSION }}.tgz" \
+            oci://ghcr.io/${{ github.repository_owner }}/charts