Enable Docker image push on pull requests

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/build.yml

@@ -168,7 +168,6 @@ jobs:
         uses: docker/setup-buildx-action@v3
 
       - name: Log in to GHCR
-        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: ${{ env.REGISTRY }}
@@ -193,6 +192,7 @@ jobs:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           tags: |
             type=ref,event=branch
+            type=ref,event=pr
             type=sha,prefix=
             type=raw,value=latest,enable=${{ github.ref == 'refs/heads/develop' }}
             type=raw,value=${{ steps.version.outputs.version }},enable=${{ inputs.version != '' }}
@@ -202,7 +202,7 @@ jobs:
         with:
           context: .
           platforms: linux/amd64,linux/arm64
-          push: ${{ github.event_name != 'pull_request' }}
+          push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           build-args: |