Chez Phase 2 (inc D): records + protocols

The largest remaining crash bucket: defrecord/deftype/defprotocol/extend-type/
reify. make-deftype-ctor/make-protocol/protocol-dispatch/register-method/
satisfies?/extenders/instance-check/make-reified were ctx-capturing seed natives
resolving to jolt-nil.

records.ss adds a jrec type (tag + field alist), set!-extended into every
collection dispatcher (get/=/hash/count/keys/vals/seq/assoc/conj/contains?/map?/
pr-str/pr-readable/str) via the transients.ss capture-prev pattern, plus a
protocol registry (type-tag -> proto -> method -> fn) and dispatch over record
tags / host-type candidates. (get rec :jolt/deftype) returns the tag, so the
overlay record? works unchanged. A record equals another of the same type with
equal fields, is map?/coll? not vector?, prints #ns.Name{...}, and str uses a
custom Object toString impl when defined.

emit.janet :host-call now routes a non-shimmed method to record-method-dispatch
(was an emit-fail), so (.protoMethod record args) compiles; .-field access is
still analyzer-punted (deferred).

Prelude parity 1652 -> 1701, 0 new divergences. 4 print-method-multimethod cases
moved crash->allowlist (the printer doesn't consult a custom print-method yet).
jolt-jgoc.

host/chez/rt.ss

@@ -186,6 +186,13 @@
 ;; jolt-pr-str (above), and the var-cell machinery — so loaded last.
 (load "host/chez/multimethods.ss")
 
+;; records + protocols (jolt-jgoc, Phase 2 inc D): defrecord/deftype/defprotocol/
+;; extend-type/reify. A jrec record type set!-extended into the collection
+;; dispatchers + a protocol registry. After multimethods.ss (chez-current-ns) and
+;; the dispatchers/printers it wraps (collections/seq/values/converters/printing/
+;; transients).
+(load "host/chez/records.ss")
+
 ;; dynamic vars (jolt-9ls5): *clojure-version* / *unchecked-math* constants the seed
 ;; binds natively. After collections.ss (jolt-hash-map) + def-var!.
 (load "host/chez/dynamic-vars.ss")