Function parse_pmc_xml 

pub fn parse_pmc_xml(
    xml_content: &str,
    pmcid: &str,
) -> Result<PmcArticle, ParseError>

Parse PMC XML content into a PmcArticle domain model.

This function acts as a coordinator that delegates parsing tasks to specialized parser modules for better maintainability and separation of concerns. It directly produces domain types without going through legacy intermediate models.