dsh Session Manager (Session Management Plugin)

The DeepSeek Harness (DSH) Session Management plugin centrally manages all sessions via the "Settings → Session Management" page. Core features include restoring archived sessions, multi-step deletion (including delayed deletion of running sessions), batch operations (multi-select, delete all, restore all), and grouping by workspace. Installation requires cloning the repository locally and running `dsh plugin add`, then restarting for changes to take effect. The plugin synchronizes data using `host/archived-sessions-changed` frames. Deletion involves cleaning up workspaces, archived collections, and on-disk logs. It also supports removing orphaned IDs and persists state to `.session-manager-state.json`.