Function render 

pub fn render(
    ctx: &Context,
    update_result: &UpdateCheckResult,
    current_version: &str,
    installation_type: InstallationType,
    installing: bool,
    install_status: Option<&str>,
) -> UpdateDialogAction

Render the update dialog overlay.

Call this when show_update_dialog is true. Returns the user’s action.

When installing is true, the Install button is disabled and shows “Installing…”. The install_status message (if any) is displayed below the buttons.