- Change BUILTIN_PREDICATES[15] arity from 1 to 2 to match binary usage
in the FOL compiler and topology engine
- Update evaluator to handle both unary (does element have stacking context)
and binary (do both elements share the same stacking context) cases
- Binary comparison: both elements must have a valid stacking context
AND their stackingContextOf values must match
- Aligns predicate semantics with the legacy engine in solver/topology.ts
and the topology query layer's inStackingContext(graph, subj, ref?) API
John Dvorak
5830d5861e