Introducing the DeepSeek Harness Plugin: `pepsi-ai/dsh-session-delete`

`pepsi-ai/dsh-session-delete` is a DeepSeek Harness plugin designed to address the difficulty of session cleanup. It adds a trash button and a sidebar menu item in the UI and provides the `workbench_session_delete` Agent tool to enable complete session deletion. The plugin features risk confirmation, stopping active sessions, and synchronous cleanup of caches and billing records, and it must be installed for the specified profile and restarted to take effect.