dsh-step-clock: Real-Time Step Duration Monitoring for DeepSeek Harness

The built-in turn timer in the DeepSeek Harness (DSH) web interface suffers from latency and insufficient granularity. The `dsh-step-clock` plugin provides real-time, step-level timing to address this. It displays the current step's elapsed time, tool name, and status above the input box, supports concurrent steps and thinking steps, and retains completed steps in the display. The plugin relies on Facts data from the DSH engine, requires no polling, and is suitable for developers who need to accurately monitor execution time. The installation command is `dsh plugin --profile web add @climber47/dsh-step-clock`.