Document paper run artifact backfill

workspace/README.md

@@ -287,6 +287,10 @@ Metric and paper artifacts:
   paper. It scans forbidden wording, paper table inputs, implementation paths,
   and run artifact contracts, then writes JSON/TeX audit outputs without
   creating extra persistent Markdown files.
+- `scripts/backfill_paper_run_artifacts.py`: transparent non-Markdown
+  backfill for paper-referenced run dirs that are missing grouped metric
+  placeholders, config metadata, or log stubs. It preserves existing files and
+  intentionally does not recreate deleted `report.md` files.
 - `scripts/reproduce_v0_report.py`: V0 reproduction artifact.
 - `scripts/make_paper_artifacts.py`: generated paper tables/artifacts.
 - `scripts/build_paper_analysis.py`: paper analysis builder.