fix: Update image optimization workflow to push to current branch

- Change git push from main to HEAD to work with feature branches
- Fixes 'src refspec main does not match any' error
- Ensures image optimization works on all branches

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

Author: hobbytp

.github/workflows/image-optimization.yml

@@ -88,5 +88,5 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.MY_GITHUB_TOKEN }}
         run: |
           git remote set-url origin https://x-access-token:${GITHUB_TOKEN}@github.com/${{ github.repository }}.git
-          git push origin main
+          git push origin HEAD
           echo "推送优化后的图片到仓库"