Separate eval from render: render-active? gate in eval-list

eval-list only dispatches to the render adapter when render-active? is true.
render-to-html and aser set render-active! on entry. Pure evaluate() calls
no longer stringify component results through the render adapter.

Fixes component children parity: (defcomp ~wrap (&key &rest children) children)
now returns [1,2,3] in eval mode, renders to "123" only in render mode.

Parity: 112/116 pass (remaining 4 are hand-written evaluator.py bugs).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/sx/ref/adapter-html.sx

@@ -15,6 +15,7 @@
 
 (define render-to-html
   (fn (expr env)
+    (set-render-active! true)
     (case (type-of expr)
       ;; Literals — render directly
       "nil"     ""