Push Docker images on PRs for Pi testing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/docker-publish.yml

@@ -63,7 +63,7 @@ jobs:
         uses: docker/build-push-action@v5
         with:
           context: .
-          push: ${{ github.event_name != 'pull_request' }}
+          push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           platforms: linux/amd64,linux/arm64
@@ -103,7 +103,7 @@ jobs:
         with:
           context: ./frontend
           file: ./frontend/Dockerfile
-          push: ${{ github.event_name != 'pull_request' }}
+          push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           platforms: linux/amd64,linux/arm64