Fix conformance gaps: exception types, byte/getBytes, host classes

Shake-out from the conformance-library sweep. Host-side fixes (runtime .ss,
no re-mint) plus one analyzer change (re-minted):

- Exception fidelity: ex-info and host-constructed throwables (RuntimeException.
  etc.) now carry their JVM class, so (class e), instance? across the exception
  hierarchy, .getMessage, and clojure.test thrown?/thrown-with-msg? all work.
- .getBytes returns a seqable/countable byte-array and honors UTF-16/UTF-32;
  String. decodes them. ->bytevector accepts byte-arrays (Base64).
- Universal .getClass / .toString / .indexOf / .lastIndexOf on any value/seq.
- record? uses the host jrec? predicate (the old (get x :jolt/deftype) crashed
  on a sorted-map by invoking its comparator).
- extend-protocol to abstract host types (clojure.lang.Fn/IFn/APersistentVector,
  java.net.URI) dispatches.
- New host classes: clojure.lang.PersistentQueue, java.util.ArrayList,
  java.net.URI, java.io.File / java.util.UUID ctors, Double/Float ctors+statics,
  regex instance? Pattern, System/setProperty.
- *assert* / *print-readably* are real settable/bindable vars.
- (symbol "ns/name") splits the namespace at the last slash.
- letfn fn params desugar destructuring (analyzer; re-minted).

unit.edn gains exinfo/hostobj/queue/hostctor/destructure regression rows.

jolt-core/jolt/analyzer.clj

@@ -241,10 +241,12 @@
         env* (add-locals env names)
         binds (mapv (fn [spec]
                       (let [cl (vec (form-elements spec))]
-                        ;; analyze as a named fn (items[1] = the name): self- and
-                        ;; sibling-calls resolve, the fn carries its own name.
+                        ;; Build (fn name [params] body*) and analyze through the fn
+                        ;; MACRO so destructuring params desugar (the fn* primitive
+                        ;; would not — same trick defmacro uses). The named fn means
+                        ;; self- and sibling-calls resolve and it carries its own name.
                         [(form-sym-name (first cl))
-                         (analyze-fn ctx (vec (cons (first cl) cl)) env*)]))
+                         (analyze ctx (cons (symbol "fn") cl) env*)]))
                     specs)]
     {:op :let :letrec true :bindings binds
      :body (analyze-seq ctx (drop 2 items) env*)}))