feat: add remove PR preview workflow (#118)

* feat: add remove PR preview workflow

* fix: do not fail if not exist

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: shenxianpeng

.github/workflows/remove-preview.yml

@@ -0,0 +1,29 @@
+name: Remove PR Preview
+
+on:
+  pull_request:
+    types: [closed]
+
+jobs:
+  cleanup-preview:
+    if: github.event.pull_request.merged == true
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout gh-pages branch
+        uses: actions/checkout@v4
+        with:
+          ref: gh-pages
+          persist-credentials: true
+
+      - name: Remove preview folder
+        run: |
+          rm -rf previews/${{ github.event.pull_request.number }} || true
+
+      - name: Commit and push changes
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add -A
+          git commit -m "Remove preview for PR #${{ github.event.pull_request.number }}"
+          git push