dsh-prism: Adds a "Simplified Mode" to the DSH Interface

# Preface The philosophy of DeepSeek Harness (hereinafter referred to as DSH) is "everything is a plugin." This design offers sufficient flexibility, but it also presents a usability threshold on the interface. During a single task, the model sequentially calls a chain of tools, causing the native interface to scroll through a long list of tool cards where terminology, parameters, and status are intermingled. New users attempting to get started struggle to discern "what exactly happened in this turn," while veteran users familiar with the system require complete information and do not wish for the interface to be oversimplified. The native interface offers only one mode of interpretation, leaving both groups to compromise on a single presentation. dsh-prism addresses this issue by adding two modes to DSH's Web UI: "Simplified" for those seeking efficiency, and "Native" to restore the original experience for experts. It features one-click switching and can be uninstalled without leaving a trace when no longer needed. The following sections introduce its features, installation, and usage.