ci: finalize nanoGPT stale-completion guard

Author: charlesmartin14

.github/workflows/fix-nanogpt-stale-completion-final.yml

@@ -0,0 +1,98 @@
+name: Finalize nanoGPT stale-completion guard
+
+on:
+  push:
+    branches:
+      - "agent/fix-nanogpt-stale-completion"
+    paths:
+      - ".github/workflows/fix-nanogpt-stale-completion-final.yml"
+
+permissions:
+  contents: write
+
+jobs:
+  patch-test-and-publish:
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: agent/fix-nanogpt-stale-completion
+          fetch-depth: 0
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+          cache: pip
+          cache-dependency-path: baseline/nanogpt_one_head/pyproject.toml
+
+      - name: Apply reviewed guard and align synthetic checkpoint inventory
+        shell: bash
+        run: |
+          set -euo pipefail
+          awk '
+            /- name: Reapply the reviewed patch and repair transcription typos/ {
+              section=1
+              next
+            }
+            section && /run: \|/ { capture=1; next }
+            capture && /^      - name:/ { exit }
+            capture { sub(/^          /, ""); print }
+          ' .github/workflows/fix-nanogpt-stale-completion-retry.yml \
+            > /tmp/apply_guard.sh
+          bash /tmp/apply_guard.sh
+
+          python - <<'PY'
+          from pathlib import Path
+
+          path = Path("baseline/nanogpt_one_head/tests/test_completion.py")
+          text = path.read_text(encoding="utf-8")
+          needle = "    return run_dir, fingerprint, total_steps\n"
+          if text.count(needle) != 1:
+              raise RuntimeError("unexpected completed-run fixture return shape")
+          replacement = '''\
+    # Keep the synthetic fixture's physical checkpoint inventory identical to
+    # the exact paths persisted in epoch_metrics.csv.
+    inventory = pd.read_csv(run_dir / "epoch_metrics.csv")
+    for value in inventory["checkpoint_path"]:
+        checkpoint_path = Path(str(value))
+        checkpoint_path.parent.mkdir(parents=True, exist_ok=True)
+        if not checkpoint_path.is_file():
+            checkpoint_path.write_bytes(b"synthetic epoch checkpoint")
+    return run_dir, fingerprint, total_steps
+'''
+          path.write_text(text.replace(needle, replacement, 1), encoding="utf-8")
+          PY
+
+      - name: Install one-head nanoGPT test environment
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install torch --index-url https://download.pytorch.org/whl/cpu
+          python -m pip install -e './baseline/nanogpt_one_head[dev]'
+          python -m pip check
+
+      - name: Compile and test one-head package
+        env:
+          PYTHONPATH: baseline/nanogpt_one_head/src
+          MPLBACKEND: Agg
+        run: |
+          git diff --check
+          python -m compileall -q \
+            baseline/nanogpt_one_head/src \
+            baseline/nanogpt_one_head/tests
+          pytest -q baseline/nanogpt_one_head/tests
+
+      - name: Commit tested fix
+        shell: bash
+        run: |
+          set -euo pipefail
+          git config user.name "github-actions[bot]"
+          git config user.email \
+            "41898282+github-actions[bot]@users.noreply.github.com"
+          git add \
+            baseline/nanogpt_one_head/src/rg_nanogpt_one_head/completion.py \
+            baseline/nanogpt_one_head/src/rg_nanogpt_one_head/engine.py \
+            baseline/nanogpt_one_head/src/rg_nanogpt_one_head/run_utils.py \
+            baseline/nanogpt_one_head/tests/test_completion.py
+          git commit -m "Reject stale completed one-head nanoGPT runs"
+          git push origin HEAD:agent/fix-nanogpt-stale-completion