Removes ALL hardcoding. Every constant-key map literal in user code becomes a
shape-rec (a Janet tuple [descriptor v0 v1 ...]); the descriptor is interned
per key SET with a single canonical key order owned by the runtime
(types/shape-sort), so every site that builds or reads a shape agrees.
Consistency is the foundation: shape-recs are made UNCONDITIONALLY for
const-key user maps (emit-map), not gated on the inference — so a value's
representation always matches what the type system claims, which was the bug
that broke the earlier generalization (a ray built as a struct but bare-indexed
as a shape). Gated on :inline? so it applies to user data only, never to core
or the compiler's own IR-node maps.
Transparency layer (the shape-rec block now lives in types.janet, reachable by
core + evaluator + backend): get, assoc, dissoc, count, contains?, map?, first,
seq, the central realize-for-iteration normalizer (keys/vals/reduce-kv), eq-map-
pairs + eq-seqable (equality), pr-render (print), jolt-call (compiled IFn), and
the interpreter's coll-lookup all handle shape-recs. A new spec
(shape-transparency-test) asserts each op matches the equivalent struct map,
including nil/false values (which shape-recs store positionally — unlike
structs).
The ray tracer renders byte-identically (mean 122.04). Gate green with the flag
off, suite 4718. NOT yet faster — every field read currently takes the
descriptor path because the inference drops the complete :shape through joins
and containers; that's Round 2 (completeness preservation). All behind
JOLT_SHAPE (off by default).
