Function rewrite_ids 

pub fn rewrite_ids(
    graphs: &mut PluginGraphs,
    target: &Path,
    roots: &HashMap<String, String>,
)

Rewrite all node id, parent and edge from/to fields from the raw cargo-based IDs to short human-readable IDs.

Scheme:

• crate:{pkg_repr} → crate:anyhow / crate:anyhow@1.0.102 (conflict)
• mod:{pkg_repr}::{path} → mod:anyhow::{path}
• trait:{pkg_repr}::{path} → trait:anyhow::{path}
• file:{abs_path} → file:{rel_path} (relativized via roots)