dsh-session-reference: DeepSeek Harness Cross-Session Reference Plugin

`dsh-session-reference` is a memory plugin for DeepSeek Harness that enables cross-session references for agents. It provides an `@` menu, session priority ranking, and a `dsh-session:` serialization protocol, supporting responsive capsules and persistent context insertion. Users must install it manually. It requires DSH 0.1.0-rc.5 and Node.js 22.19 or higher. By default, it limits references to three per message, which can be adjusted through configuration. The plugin runs with process-level permissions and is suitable for developing cross-session connectivity scenarios.