fix(ci): restore PR+auto-merge for sync-frontend workflow (#28)

Branch protection requires CI checks before merge, so auto-merge now
works correctly — it waits for the Backend check to pass then merges.

Co-authored-by: Kelin <kelin@KelindeMacBook-Air.local>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/sync-frontend.yml

@@ -5,6 +5,7 @@ on:
 
 permissions:
   contents: write
+  pull-requests: write
 
 jobs:
   sync:
@@ -30,14 +31,21 @@ jobs:
           mkdir -p ui/static
           tar -xzf frontend-dist.tar.gz -C ui/static
 
-      - name: Commit and push to main
+      - name: Check for changes
+        id: diff
         run: |
           git add ui/static/
           if git diff --cached --quiet; then
-            echo "Frontend is already up to date. Nothing to sync."
-            exit 0
+            echo "changed=false" >> $GITHUB_OUTPUT
+          else
+            echo "changed=true" >> $GITHUB_OUTPUT
           fi
 
+      - name: Commit, open PR and enable auto-merge
+        if: steps.diff.outputs.changed == 'true'
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
           git config user.name "github-actions[bot]"
           git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
 
@@ -45,7 +53,18 @@ jobs:
             --repo HuangYuChuh/ComfyUI_Skills_OpenClaw-frontend \
             --json tagName -q '.tagName' || echo "latest")
 
+          BRANCH="build/frontend-${FRONTEND_SHA}"
+          git checkout -b "$BRANCH"
           git commit -m "build(ui): sync frontend assets from upstream@${FRONTEND_SHA}"
-          git push origin main
-        env:
-          GH_TOKEN: ${{ github.token }}
+          git push origin "$BRANCH"
+
+          PR_URL=$(gh pr create \
+            --title "build(ui): sync frontend assets from upstream@${FRONTEND_SHA}" \
+            --body "Auto-generated by \`sync-frontend\` workflow." \
+            --base main)
+
+          gh pr merge "$PR_URL" --auto --squash
+
+      - name: No changes
+        if: steps.diff.outputs.changed == 'false'
+        run: echo "Frontend is already up to date. Nothing to sync."