Function get_available_groups 

pub async fn get_available_groups(
    infra: &InfraContext<'_>,
    token: &str,
) -> Result<Vec<String>, Error>

List the group names accessible to the caller.

Thin forwarder; used by handlers that need the raw accessible-group label list without the access-validation logic baked into crate::service::authorization::validate_user_group_access. Service code that needs the full Vec<Group> (including members) should call get_group_available on the backend directly — this helper is intentionally label-only.