Function run_communities 

pub fn run_communities(
    db: &FactsDb,
    opts: &Options,
) -> Result<CommunitiesResult>

Run Leiden community detection on the Fisher-significant coupling pairs.

Errors

Returns CodeLoreError::Analysis if the upstream coupling query fails or if leiden-rs reports an internal error (malformed input, numerical breakdown — neither expected on the well-formed inputs coupling::run_coupling produces, but the error path stays typed).