dsh-session-batch: DSH Session Batch Cleanup and Real Runtime Status

By default, DSH only archives sessions and does not provide a deletion API. Logs accumulate long-term in $DSH_HOME/sessions, and the sidebar makes it difficult to distinguish between sessions that are truly running and those merely resident in memory. The plugin dsh-session-batch supports multi-select batch deletion of chat records in the sidebar's Batch purge panel, with an optional link to dsh-session-artifacts to delete conversation output files; it uses 'Running' and 'In memory' badges to reflect the status of workspace/session-activity and the host Session object. After installation, a full restart of DSH is required. Deletions are permanent without a recycle bin, and a maximum of 200 sessions can be deleted per batch. MIT License, maintainer ajsney764-blip.