Constant META_OIDC_AUDIENCES 

pub const META_OIDC_AUDIENCES: &str = "oidc_audiences";

Records the comma-joined list of id_tokens.aud: values when GitLab CI declares the audience as a YAML sequence (multi-cloud broker — strongest over-scoping signal). When set, the legacy META_OIDC_AUDIENCE field holds the same comma-joined string for backward compatibility, and this field is the explicit “this was a list” marker. Set by the GitLab parser only on the multi-aud path; absent for scalar aud: values.