feat(ci): add autonomous Klaude Cold auto-sweep (#2830)

Select image refresh candidates from public APIs and cluster utilization, exclude
overlapping open PRs with structured Claude review, and run autonomous candidate
sessions with benchmark evidence and bounded repairs. Mark Klaude benchmark jobs
for background scheduling and document operation in English and Chinese.

通过公开 API 和集群利用率选择镜像更新候选，以 Claude 结构化检查排除重复 PR，
再交由自主候选会话完成 benchmark、有限次数修复及证据报告。为 Klaude benchmark
任务添加后台调度标记，并提供同步的中英文操作文档。