Function topic 

pub fn topic(operator: &str, kind: &str) -> String

Builds a multi-operator SpatialDDS topic name: sdds/<operator>/<kind>. SpatialDDS namespaces topics per operator so federated fleets share a world model without colliding; operator is the operator/tenant id, kind the SpatialDDS message kind (e.g. "GeoPose", "FramedPose").