shared-handoff-dsh: Cross-Platform Task State Management and Session Handoff for DeepSeek Harness

`shared-handoff-dsh` is a DeepSeek Harness skill plugin designed to address the continuity challenges of repository-level state and session context. It encapsulates the core workflow of `shared-handoff-kit`, providing a zero-dependency, cross-platform automation solution. The plugin's core features include evidence-based session handoff and recovery, as well as repository-local task ID state management. It supports quickly starting tasks, binding sessions, or exporting context through conversational commands (such as `task-id-bootstrap` and `handoff`). Its automation mechanism is implemented via the DSH event system, requiring no manual intervention and compatible with the state layouts of Codex and Claude. The plugin natively supports Windows 10/11 differences and includes compression.