- Implemented a new `/roster` endpoint to retrieve and manage device configurations.
- Added HTML template for the roster page with a table to display device status and actions.
- Introduced functionality to add, edit, and delete devices via the roster interface.
- Enhanced `ConfigPayload` model to include polling options.
- Updated the main application to serve the new roster page and link to it from the index.
- Added validation for polling interval in the configuration payload.
- Created detailed documentation for the roster management features and API endpoints.
