dsh-archive-sessions: DeepSeek Harness Archived Session Management

The `dsh-archive-sessions` plugin is designed to address the difficulty of managing archived DeepSeek Harness (DSH) sessions. It provides a persistent view through Settings, allowing users to view archived sessions, restore them to the sidebar, or permanently delete them. After installation, it can be accessed via “Settings → Archived Sessions.” Clicking Restore recovers a session, while clicking Delete requires confirmation and removes the associated log file. Note that deletion requires full permissions and is irreversible.