ci: remove stale PyTorch guide references

Author: TheHiddenObserver

.github/workflows/docs-pr84-remove-stale-links.yml

@@ -0,0 +1,50 @@
+name: PR84 Remove Stale Documentation Links
+
+on:
+  push:
+    branches: [agent/readme-layout-cleanup]
+
+permissions:
+  contents: write
+
+jobs:
+  remove-stale-links:
+    if: github.event.head_commit.message != 'docs: remove stale PyTorch guide references'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: agent/readme-layout-cleanup
+      - name: Remove references to absent historical artifacts
+        shell: bash
+        run: |
+          python3 - <<'PY'
+          from pathlib import Path
+
+          names = (
+              "torch_vs_cupy_comprehensive_report.md",
+              "knockoff_fdr_2026-04-18_09-15-29.md",
+              "torch_vs_cupy_20260418_092648.md",
+          )
+          for filename in (
+              "docs/en/guides/pytorch-backend.md",
+              "docs/cn/guides/pytorch-backend.md",
+          ):
+              path = Path(filename)
+              lines = path.read_text(encoding="utf-8").splitlines()
+              kept = [line for line in lines if not any(name in line for name in names)]
+              with path.open("w", encoding="utf-8", newline="\n") as handle:
+                  handle.write("\n".join(kept) + "\n")
+          PY
+      - name: Commit reference cleanup
+        shell: bash
+        run: |
+          if git diff --quiet -- docs/en/guides/pytorch-backend.md docs/cn/guides/pytorch-backend.md; then
+            echo "No stale references remain."
+            exit 0
+          fi
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git add docs/en/guides/pytorch-backend.md docs/cn/guides/pytorch-backend.md
+          git commit -m "docs: remove stale PyTorch guide references"
+          git push origin HEAD:agent/readme-layout-cleanup