The build GitHub Actions job failed because the metrics steps authenticated with secrets.METRICS_TOKEN and received Bad credentials. This change removes dependency on that external PAT for this workflow and aligns setup docs with the actual auth model.

• Workflow auth change (build failure root cause)

  • Updated all lowlighter/metrics steps in .github/workflows/generate-stats.yml to use the built-in ${{ github.token }} instead of secrets.METRICS_TOKEN.
  • Keeps auth scoped to the workflow run and avoids breakage from missing/expired custom secrets.

• Setup/troubleshooting docs alignment

  • Updated SETUP.md to reflect that METRICS_TOKEN is no longer required.
  • Added explicit guidance to enable Actions → Workflow permissions → Read and write, which is required for the commit output mode used by the workflow.

# .github/workflows/generate-stats.yml
with:
  token: ${{ github.token }}
  output_action: commit
  committer_branch: main