Add DoodleBUGS PR Preview cleanup workflow

.github/workflows/DoodleBUGSPreviewCleanup.yml

@@ -0,0 +1,36 @@
+name: DoodleBUGS PR Preview Cleanup
+
+on:
+  pull_request:
+    types: [closed]
+    paths:
+      - 'DoodleBUGS/**'
+      - '.github/workflows/DoodleBUGSpreview.yml'
+      - '.github/workflows/DoodleBUGSPreviewCleanup.yml'
+
+permissions:
+  contents: write
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout gh-pages branch
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Delete DoodleBUGS preview and push changes
+        run: |
+          if [ -d "DoodleBUGS/pr-previews/$PRNUM" ]; then
+            git config user.name "github-actions[bot]"
+            git config user.email "github-actions[bot]@users.noreply.github.com"
+            git rm -rf "DoodleBUGS/pr-previews/$PRNUM"
+            git commit -m "DoodleBUGS: Delete preview for PR $PRNUM"
+            git push origin gh-pages
+          else
+            echo "No DoodleBUGS preview found for PR $PRNUM"
+          fi
+        env:
+          PRNUM: ${{ github.event.number }}