Function render_site_single_file 

pub fn render_site_single_file(
    site: &SiteConfig,
    pages: &[PageEntry],
    nav_items: &[(String, String)],
    config: &PageConfig,
) -> String

Render an entire multi-page site as a SINGLE self-contained HTML document.

Every ::page route becomes a <section class="surfdoc-page" data-route> inside one <main>; a shared ::nav/footer chrome wraps them and the inlined [SITE_SPA_ROUTER_JS] switches sections client-side. This is the model used by the example showcase, where each app is one artifact loaded in an iframe (absolute-path nav can’t work across nested iframe origins).

Contrast render_site_page, which emits one file per route (clean URLs, needs a server that maps routes → files).