fix(ci): retry README auto-commit push on race (rebase + up to 5 attempts)

.github/workflows/update-readme.yml

@@ -45,5 +45,23 @@ jobs:
           git config --global user.name 'github-actions[bot]'
           git config --global user.email 'github-actions[bot]@users.noreply.github.com'
           git add README*.md
-          git diff --quiet && git diff --staged --quiet || git commit -m "docs: auto-update README [skip ci]"
-          git push
+          # 没有变更就直接退出，别浪费 attempt 次数
+          if git diff --quiet && git diff --staged --quiet; then
+            echo "No README changes to commit."
+            exit 0
+          fi
+          git commit -m "docs: auto-update README [skip ci]"
+
+          # 推回 main 时处理 push race：并发 run 或人工 push 都可能抢先到 remote，
+          # 这里最多重试 5 次，每次失败就 rebase 到最新 main 再试。
+          for i in 1 2 3 4 5; do
+            if git push; then
+              echo "Pushed on attempt $i"
+              exit 0
+            fi
+            echo "Push rejected on attempt $i; rebasing onto latest main and retrying..."
+            git pull --rebase origin main
+            sleep $((i * 2))
+          done
+          echo "Push still failing after 5 attempts" >&2
+          exit 1