Function render_html_reflow_ttf_with 

pub fn render_html_reflow_ttf_with(
    source: Option<&[VertBox]>,
    geometry: &PageGeometry,
    store: &TtfFontStore,
    images: &[ImageResource],
    extras: &DocExtras,
    links: &[(DecoId, AnnotAction)],
    dests: &[(DecoId, String)],
) -> Result<String, HtmlError>

Same as render_html_reflow, but rendering under a real TtfFontStore — the document’s faces are then NAMED (crate::fonts::reflow_font_stack) rather than left to the stylesheet’s generic stack: the dominant face goes on the body rule (css.rs), and only a run that departs from it names a family of its own (inline.rs’s emit_run) — so the bulk of the prose stays bare text with no <span> at all. Nothing is embedded; see crate::fonts for why a reflowed document does not pay for that.