kernel: map/filter/reduce + with-env applicative constructor + 10 tests [shapes-reflective]

Added kernel-make-primitive-applicative-with-env in eval.sx — IMPL
receives (args dyn-env), needed by combinators that re-enter the
evaluator. map/filter/reduce in runtime.sx use it to call user-supplied
combiners on each element with the caller's dynamic env preserved.
Sketched the env-blind vs env-aware applicative split as a new entry
in the proposed combiner.sx reflective API. 289 tests total.

lib/kernel/eval.sx

@@ -118,6 +118,14 @@
     (kernel-wrap
       (kernel-make-primitive-operative (fn (args dyn-env) (impl args))))))
 
+;; As above, but IMPL receives (args dyn-env). Used by combinators that
+;; re-enter the evaluator (map, filter, reduce, apply, eval, ...).
+(define kernel-make-primitive-applicative-with-env
+  (fn (impl)
+    (kernel-wrap
+      (kernel-make-primitive-operative
+        (fn (args dyn-env) (impl args dyn-env))))))
+
 ;; ── The evaluator ────────────────────────────────────────────────
 
 (define