Claude Code-style native DeepSeek Harness sidebar for VS Code: self-written chat UI (no iframe) reusing the existing dsh web service — workspace-synced sessions, sandbox-permission/model/reasoning pickers, context ring. / VS Code 里的 Claude Code 风格 DeepSeek Harness 原生侧边栏:自写聊天 UI(无 iframe),复用现有 dsh web 服务;工作区会话同步、沙箱权限/模型/推理档选择、上下文占用环。