Host shims and protocol fixes shaken out by aws-api

Running cognitect aws-api's pure test namespaces (signing/shapes/protocols/
util/retry/endpoints) surfaced general gaps:

- extend-protocol/extend-type accept a computed class type, e.g.
  (Class/forName "[B") for the byte-array class — the byte-array idiom data.json
  and aws-api use. The macro grouping handled only symbol/nil heads (it crashed on
  a list type); type->name resolves a Class value via .getName; a byte-array
  dispatches on the "[B" host tag.
- java.nio.ByteBuffer over a jolt byte-array (wrap/allocate/get/put/array/
  remaining/position/limit/duplicate/flip), plus extend-protocol to it.
- java.util.Arrays (equals/copyOf/copyOfRange/fill) and java.util.Random
  (nextBytes/nextInt/…).
- java.net.URI/create and clojure.lang.RT/baseLoader statics.
- clojure.core.async/promise-chan (deliver-once, peek-don't-pop).
- a failed java.time parse throws DateTimeParseException (typed), so
  (catch DateTimeParseException …) matches it instead of leaking an untyped
  condition.

The XML side lives in the jolt-lang/xml library (libxml2 over jolt.ffi); ByteBuffer
stays in core as a generic java.nio primitive.

Gate: make test green (corpus +6 JVM-certified rows, 0 NEW divergence; unit
553/553; SCI 211).

host/chez/records.ss

@@ -203,6 +203,13 @@
         ((or (cseq? obj) (empty-list-t? obj)) '("ASeq" "ISeq" "IPersistentCollection" "Sequential" "Collection" "Iterable" "java.lang.Iterable" "Object"))
         ;; java.net.URI jhost — extend-protocol java.net.URI (hiccup ToURI/ToStr).
         ((and (jhost? obj) (string=? (jhost-tag obj) "uri")) '("URI" "java.net.URI" "Object"))
+        ;; a ByteBuffer — extend-protocol java.nio.ByteBuffer (aws-api util).
+        ((and (jhost? obj) (string=? (jhost-tag obj) "byte-buffer")) '("ByteBuffer" "java.nio.ByteBuffer" "Object"))
+        ;; arrays dispatch by their JVM array-class name — extend-protocol to
+        ;; (Class/forName "[B") for byte[] (data.json, aws-api), "[C" for char[].
+        ((and (jolt-array? obj) (eq? (jolt-array-kind obj) 'byte)) '("[B" "Object"))
+        ((and (jolt-array? obj) (eq? (jolt-array-kind obj) 'char)) '("[C" "Object"))
+        ((jolt-array? obj) '("[Ljava.lang.Object;" "Object"))
         ;; a regex VALUE — extend-protocol java.util.regex.Pattern (core.match.regex).
         ((regex-t? obj) '("Pattern" "java.util.regex.Pattern" "Object"))
         ;; host value types a library may extend a protocol to by class (data.json
@@ -288,7 +295,10 @@
                 "Duration" "Period" "LocalDate" "LocalTime" "LocalDateTime"
                 "ZonedDateTime" "OffsetDateTime" "OffsetTime" "ZoneId" "ZoneOffset"
                 "Clock" "Year" "YearMonth" "Month" "DayOfWeek"
-                "ChronoUnit" "ChronoField" "TemporalAmount" "TemporalUnit" "TemporalField"))
+                "ChronoUnit" "ChronoField" "TemporalAmount" "TemporalUnit" "TemporalField"
+                ;; ByteBuffer + JVM array classes (extend-protocol to (Class/forName "[B"))
+                "ByteBuffer" "java.nio.ByteBuffer"
+                "[B" "[C" "[I" "[J" "[D" "[Ljava.lang.Object;"))
     h))
 (define (strip-prefix s p)
   (let ((pl (string-length p)))