Handle flattened artifact extraction in release asset publishing workflow

[Copilot]

The publish-release / publish job failed because the reusable release workflow assumed downloaded artifacts always extract to release-assets/<artifact-name>/. In the failing run, the artifact was extracted directly into release-assets/, so ZIP packaging aborted before upload.

• Root cause

  • publish-release-assets.yml only supported one extraction layout (release-assets/<artifact-name>), but actions/download-artifact@v8 can produce a flattened layout for single-artifact downloads.

• Workflow logic update

  • Added a guarded fallback for ZIP mappings:
    • keep using release-assets/<artifact-name> when present.
    • if missing, allow fallback to release-assets/ only when there is exactly one ZIP mapping and release-assets/ is non-empty.
  • This preserves strict behavior for multi-mapping cases and still fails fast on unexpected layouts.

• ZIP output path hardening

  • Switched ZIP destination to an absolute path ($(pwd)/release-upload/...) to avoid relative-path breakage across different working directories/layouts.

artifact_dir="release-assets/$artifact_name"
if [ ! -d "$artifact_dir" ]; then
  if [ "$zip_mapping_count" -eq 1 ] && [ -d release-assets ] && find release-assets -mindepth 1 -print -quit | grep -q .; then
    artifact_dir="release-assets"
  else
    echo "Artifact directory not found: $artifact_dir"
    exit 1
  fi
fi

output_zip="$(pwd)/release-upload/$zip_name"
(cd "$artifact_dir" && zip -r "$output_zip" .)