Function dump_compiled_latexml_model 

pub fn dump_compiled_latexml_model() -> String

Load the embedded LaTeXML schema and return its compiled-model serialisation in the .model plain-text format. Used by tools/compileschema.sh stage 2 (and the --dump-model flag on the latexml_oxide binary) to regenerate LaTeXML.model from the same source the runtime sees.