Platform FFI reduction: remove 99 redundant PRIMITIVES registrations

Move DOM/browser operations to SX library wrappers (dom.sx, browser.sx)
using the 8 FFI primitives, eliminating duplicate native implementations.
Add scope-emitted transpiler rename — fixes 199 pre-existing test failures.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

hosts/javascript/transpiler.sx

@@ -624,6 +624,7 @@
   "scope-push!" "scopePush"
   "scope-pop!" "scopePop"
   "scope-emit!" "scopeEmit"
+  "scope-emitted" "sxEmitted"
   "scope-peek" "scopePeek"
   "provide-push!" "providePush"
   "provide-pop!" "providePop"