dsh-speed-monitor: measure the streaming speed of the model in the DSH panel

This article introduces the DSH plugin dsh-speed-monitor (maintained by doraasn, MIT, version 0.9.8). It adds a sidebar entry to DSH; the right panel uses DSH's own model list to stream test proxy/official interfaces, defaulting to one round per minute and capable of testing multiple models simultaneously. The article details the sampling method (warm-up discard, median of three, serial interval of 300ms for multiple models, and marking failures as ok/runs), metric definitions (ttfb_ms/decode_ms/total_ms/tps_decode/tps_e2e), configuration and storage paths, as well as the UI installation steps and four HTTP endpoints described in the README. It also explains why the curve is not connected at data gaps (where keys are read from ~/.dsh/.credentials.yaml) and warns that the plugin runs with the current DSH process permissions, advising users to verify the source code and license before installation.