Function create_classpath_edges 

pub fn create_classpath_edges(
    index: &ClasspathIndex,
    fqn_to_nodes: &HashMap<String, Vec<ClasspathNodeRef>>,
    provenance: &[ClasspathProvenance],
    staging: &mut StagingGraph,
)

Create inheritance, generic, annotation, module, and inner-class edges for classpath nodes.

Only creates edges where both source and target nodes exist in the graph. Missing targets are silently skipped (they may be from JARs not on the classpath).