Function documentation_model_for 

pub fn documentation_model_for(
    rel: &Path,
    snapshots: &HashMap<PathBuf, String>,
    unit_sources: &HashMap<String, Vec<PathBuf>>,
    project_root: &Path,
) -> Option<WireDocModel>

#1885: the wire page for the document at rel (project-relative), merged across every file of its unit. The unit’s files come from the round’s unit_sources (qualified name → project-relative paths) and their text from snapshots; each entry’s range is lowered against its own file and carries that file’s file:// URI, so click-to-code opens the right one. An entry whose file has no snapshot or no URI is dropped rather than sent with a wrong location. None for a suite, a file with no header, or a rel with no snapshot.