dsh-simple-view: Making the DeepSeek Harness Chat Interface Cleaner

The `dsh-simple-view` plugin optimizes the DeepSeek Harness chat interface by hiding execution logs, adjusting styles, and injecting system instructions to create a more focused view. It conceals execution details such as Think and tool calls, tightens spacing, reduces font size, keeps only error and question lines, and wraps assistant replies in chat bubbles. The plugin also allows editing the “Concise Reply Instruction” to control the model’s output style, depends on DSH Settings and Schemastery, and works right after installation.