dsh-quick-toc: DeepSeek Harness Conversation Outline Navigation Plugin

The `dsh-quick-toc` plugin provides long conversation navigation for DeepSeek Harness. It extracts Markdown headings from AI replies and generates a grouped, searchable outline panel. It supports jumping by turn, loading unread content, hierarchy filtering, and smooth scrolling, with dark theme support. The installation command is `dsh plugin --profile web add dsh-quick-toc`, requiring DSH version >= 0.1.5-rc.1.