dsh-taskboard: DeepSeek Harness Cross-Project Task Board

`dsh-taskboard` is a cross-project task board plugin designed specifically for DeepSeek Harness (DSH). It integrates the task board into the sidebar, aggregates the `todo_write` projections from all visible sessions, and provides unified view management. The plugin does not maintain standalone storage and relies entirely on DSH native mechanisms. Its features include task context tagging, native lifecycle state recognition, real-time status bar display, and support for bulk selection and archival operations. During installation, ensure version compatibility and execute the build and installation commands, then restart the Web profile to enable it.