ci(docs): add lockfile debug output for pages workflow

.github/workflows/publish_docs.yml

@@ -44,6 +44,23 @@ jobs:
           cache: "pnpm"
           cache-dependency-path: ./docs/pnpm-lock.yaml
 
+      - name: Debug lockfile on runner
+        run: |
+          pwd
+          ls -la
+          echo "sha256 (workspace file):"
+          sha256sum pnpm-lock.yaml
+          echo "sha256 (git blob at HEAD):"
+          git show HEAD:docs/pnpm-lock.yaml | sha256sum
+          echo "lockfileVersion count:"
+          grep -c '^lockfileVersion:' pnpm-lock.yaml || true
+          echo "yaml document markers:"
+          grep -nE '^---$|^\\.\\.\\.$|^<<<<<<<|^=======|^>>>>>>>$' pnpm-lock.yaml || true
+          echo "first 20 lines:"
+          sed -n '1,20p' pnpm-lock.yaml
+          echo "last 20 lines:"
+          tail -n 20 pnpm-lock.yaml
+
       - name: Install dependencies
         run: pnpm i --frozen-lockfile