This function defines the user interface for the standalone version of the alphagraph Shiny app. It uses the bs4Dash package to create a dashboard layout with a header, sidebar, and body. The sidebar contains menu items for navigating between the "Graph Editor" and "Settings" tabs. The body includes custom CSS for styling, as well as UI outputs for a context menu and overlay that will be rendered dynamically when the context menu is open. The "Graph Editor" tab contains a visNetwork graph and additional panels for description and analysis, while the "Settings" tab is currently a placeholder for future settings options.