spec.alpha: reify ILookup get, NPE/CCE, quoted #inst/#uuid, anon-fn class, kwargs map

Close clojure.spec.alpha's remaining gaps — its conform/explain/describe/multi-spec
suite (clojure.test-clojure.spec, multi-spec) now passes fully.

- (get reify k) / (:k reify) routes to a reify's clojure.lang.ILookup valAt. spec
  reifies fspec/regex specs as ILookup and reads (:args spec) off them, so before
  this instrument never saw the args spec.
- A failed numeric comparison reports the JVM class: a nil operand is
  NullPointerException, a non-number is ClassCastException (was an opaque :object
  condition). conform-explain checks the thrown class.
- A quoted / macro-form #inst / #uuid literal constructs its Date/UUID value, like
  the JVM reader (which builds it at read time). emit-quoted was emitting the raw
  tagged form, so #inst "1939" and #inst "1939-01-01T00:00:00.000-00:00" weren't =.
- An anonymous fn reports class clojure.lang.AFunction$fn (the $fn marker), so
  spec's fn-sym returns ::s/unknown for it, matching the JVM's ns$fn__N.
- A fn with & {:as m} kwargs accepts a trailing map (Clojure 1.11): (f :a 1 {:b 2})
  and (f {:a 1}) both bind m, by merging an odd trailing map over the pairs.
- A thread responds to .getStackTrace (empty — jolt does TCO).

clojure.test-clojure.instr does not fully pass: its ::caller assertions need the
calling fn's stack frame, which TCO erases (an inherent host divergence, like the
JVM keeping tail frames).

make test green (+4 corpus rows, 0 new divergences), shakesmoke byte-identical.
Re-mint (backend emit-quoted + the destructure macro).

host/chez/java/io.ss

@@ -487,6 +487,11 @@
 (register-host-methods! "thread"
   (list (cons "getContextClassLoader" (lambda (self) the-classloader))
         (cons "getName" (lambda (self) "main"))
+        ;; no reified call stack (jolt does TCO, so caller frames are erased) — an
+        ;; empty StackTraceElement[]. clojure.spec.test.alpha's instrument reads it
+        ;; to name the caller var; it degrades to no ::caller, the conform error
+        ;; (the ExceptionInfo) is still thrown.
+        (cons "getStackTrace" (lambda (self) (jolt-vector)))
         (cons "interrupt" (lambda (self)
                             (when (box? (jhost-state self)) (set-box! (jhost-state self) #t))
                             jolt-nil))