Replace the ad-hoc inference lattice (a flat :struct-map tag plus {:vec ELEM})
with one recursive structural type: {:struct {field -> T}}, {:vec T}, {:set T},
scalar tags, and :any. A keyword lookup now returns its field's type, so nested
access like (:r (:direction ray)) is typed end to end and drops its guard. join
is field-wise and element-wise with a depth cap of 4 so the inter-procedural
fixpoint still terminates.
The back end honors a struct hint on any subject node, not just locals, so an
inferred field type on a nested lookup specializes. The orchestrator's fixpoint
joins through the portable join-types so compound types no longer collapse to
:any.
Ray tracer goes 12.8s to 11.0s with no hints, matching the explicit ^:struct
version (10.9s). Render checksum unchanged (1915337), full gate green,
conformance x3 modes pass.
jolt-5uj
9bc7b27245