docs(scanner): add benchmark runbook (#3412)

Co-authored-by: Henry Guo <marshawcoco@users.noreply.github.com>

crates/scanner/README.md

@@ -6,6 +6,8 @@ admission, scanner-driven heal/bitrot checks, and namespace alerts.
 
 For operator-facing runtime controls, status fields, and tuning workflows, see
 [Scanner Runtime Controls](../../docs/operations/scanner-runtime-controls.md).
+For repeatable scanner-pressure validation, see
+[Scanner Benchmark Runbook](../../docs/operations/scanner-benchmark-runbook.md).
 
 Chinese documentation is available in [README.zh-CN.md](README.zh-CN.md).
 

crates/scanner/README.zh-CN.md

@@ -4,6 +4,8 @@ RustFS Scanner 是后台维护扫描循环，负责用量统计、生命周期
 
 面向运维人员的运行时控制项、状态字段和调参流程，请参考
 [Scanner Runtime Controls](../../docs/operations/scanner-runtime-controls.md)。
+可复现的 scanner 压力验证流程请参考
+[Scanner Benchmark Runbook](../../docs/operations/scanner-benchmark-runbook.md)。
 
 英文文档请参考 [README.md](README.md)。