Remove Prism language-* classes from code block components

highlight.py handles syntax coloring with Tailwind classes —
Prism classes were conflicting and are not needed.

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

sx/sxc/examples.sx

@@ -13,8 +13,7 @@
 
 (defcomp ~example-source (&key code)
   (div :class "bg-stone-50 border border-stone-200 rounded p-4 mt-3 overflow-x-auto"
-    (pre :class "text-sm"
-      (code :class "language-lisp" code))))
+    (pre :class "text-sm" (code code))))
 
 ;; --- Click to load demo ---