Function dispatch_render 

pub fn dispatch_render(
    document: &Document,
    registry: &Registry,
    format_name: &str,
) -> RenderPlan

Walk document and dispatch on_render for every labelled annotation / verbatim whose schema declares the format in hooks.render. Returns the plan; the caller (HTML serializer) is responsible for splicing.

format_name is matched case-insensitively against entries in schema.hooks.render. Today the HTML pipeline passes "html"; future formats pass "markdown", "latex", etc.