Function router_module_disabled 

pub(crate) fn router_module_disabled(
    module: &'static str,
    paths: &[&str],
) -> Router

A gated module’s v2 paths when its flag is off. serve_axum merges router_v2_docs last and axum keeps the last merged router’s fallback, so an unregistered v2 path would get axum’s empty 404 instead of the v2_error_envelope one.