Phase 1: Absorb sx_scope.ml (180 lines) into sx_primitives.ml. Scope stacks,
cookies, and trace infrastructure now live alongside other primitives. All 20
scope primitive registrations moved. References updated in sx_server.ml and
sx_browser.ml. sx_scope.ml deleted.
Phase 2: Transpiler handles (define name :effects (...) (fn ...)) forms.
ml-emit-define and ml-emit-define-body detect keyword at position 2 and use
(last expr) instead. Unblocks transpilation of spec/render.sx and
web/adapter-html.sx which use 4-child defines extensively.
2598/2598 tests passing.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>