dsh-steering: Responsive Steering of Model Outputs in DeepSeek Harness

`dsh-steering` is a plugin for DeepSeek Harness that addresses the latency caused by the default Steer operation waiting for a complete response. It leverages host lifecycle hooks to enable real-time reactive steering during streaming output. Its core features include reactive steering, preserving queue state, ensuring safe tool execution, and internal abort turn boundaries. After installation, it can be enabled in specific agent presets without requiring additional APIs to improve queue response efficiency. Note that it has only been validated in the DSH 0.1.5-rc.1 and Node 24.19.0 environments.