dsh-session-nexus: DSH Session Lifecycle and Cross-Session Messages Plugin

dsh-session-nexus is an unofficial MIT-licensed DSH community plugin maintained by qiushi-dev, aiming to transform DeepSeek Harness sessions into actionable objects. It primarily offers two core capabilities: first is session lifecycle control, supporting the explicit mounting of cold sessions, un-archiving, and deletion of sessions after enabling specific configurations via slash commands; the second is cross-session message interaction, allowing developers or models to deliver wake-up or silent messages to other sessions and retrieve the target session's title, timeline, and summary. The plugin supports multiple address formats, features security mechanisms such as sender attribution, anti-self-delivery, and circular limits, and enhances session ID display in the Web UI. Installation is straightforward, achievable via the `dsh plugin` command. By default, the message delivery tool is enabled while the delete function is disabled.