Function map_relation_from_remote 

pub fn map_relation_from_remote(
    tool: Tool,
    field: &str,
    value: &str,
    relation_id: &str,
) -> MappedRelation

The inverse: read a remote relation back to a local kind and target.

Symmetric with map_relation_to_remote by construction — the blocking field maps back to blocks, and nothing else maps back at all. A remote payload carrying a field this function does not recognise yields a diagnostic rather than a default, so an import cannot invent a relation the export never made.