dsh-trilogy: Project Memory Plugin for DeepSeek Harness

`dsh-trilogy` is a Host plugin for DeepSeek Harness designed to address the lack of persistent memory in models. It enforces the maintenance of three Markdown files for each workspace: `PROJECT.md` (current state), `DECISIONS.md` (decisions), and `SESSIONS.md` (logs), with automatic creation, loading, and recording. The plugin provides tools such as `memory_checkpoint` for categorized logging, supports BM25 retrieval, and includes a graphical interface for memory management. Its core lies in an intelligent injection strategy: it controls priority via a budget, automatically injects context at session start, and weights categories based on activity. All routing is limited to local access, uninstallation does not delete data, and it is suitable for development scenarios that require long-term maintenance of project context.