Function analyse_project_with 

pub fn analyse_project_with(
    roots: &Roots,
    overlay: &HashMap<PathBuf, String>,
) -> ProjectAnalysis

Slice A: analyse a project whose roots are resolved from its manifest — the same Roots compile_project consumes, resolved the same way, so the LSP discovers exactly the files bynkc compiles.

Identity is project-relative (ADR 0198): a file’s source_path here is unique across include roots.