feat: add SandBase Harness to the DSH runtime list #3

Suggested entry

SandBase Harness appears to fit the list's DSH runtime/integration scope and currently has a public release:

| - | [sandbaseai/sandbase-harness](https://github.com/sandbaseai/sandbase-harness) | 本地优先的自托管 Agent Runtime：通过原生 DSH Bundle 与 stdio MCP Bridge 接入，提供持久会话、可恢复执行、权限、凭据、审计 / 回放，以及本地、Docker、Kubernetes 和自托管 Worker 沙箱路径 | 集成与部署 | ![Stars](https://img.shields.io/github/stars/sandbaseai/sandbase-harness?style=flat) |

Verification

• Repository: https://github.com/sandbaseai/sandbase-harness
• Current release: https://github.com/sandbaseai/sandbase-harness/releases/tag/v0.3.8
• License: Apache-2.0
• Official MCP Registry: https://registry.modelcontextprotocol.io/v0.1/servers?search=io.github.sandbaseai%2Fsandbase-harness

I maintain/contribute to SandBase Harness. The description is factual and does not claim benchmark results or universal isolation guarantees.