Step 5p6 lazy loading + Step 6b VM transpilation prep

Lazy module loading (Step 5 piece 6 completion):
- Add define-library wrappers + import declarations to 13 source .sx files
- compile-modules.js generates module-manifest.json with dependency graph
- compile-modules.js strips define-library/import before bytecode compilation
  (VM doesn't handle these as special forms)
- sx-platform.js replaces hardcoded 24-file loadWebStack() with manifest-driven
  recursive loader — only downloads modules the page needs
- Result: 12 modules loaded (was 24), zero errors, zero warnings
- Fallback to full load if manifest missing

VM transpilation prep (Step 6b):
- Refactor lib/vm.sx: 20 accessor functions replace raw dict access
- Factor out collect-n-from-stack, collect-n-pairs, pad-n-nils helpers
- bootstrap_vm.py: transpiles 9 VM logic functions to OCaml
- sx_vm_ref.ml: proof that vm.sx transpiles (preamble has stubs)

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

web/adapter-dom.sx

@@ -1,3 +1,10 @@
+(import (sx dom))
+(import (sx render))
+
+(define-library (web adapter-dom)
+  (export SVG_NS MATH_NS island-scope? contains-deref? dom-on render-to-dom render-dom-list render-dom-element render-dom-component render-dom-fragment render-dom-raw render-dom-unknown-component RENDER_DOM_FORMS render-dom-form? dispatch-render-form render-lambda-dom render-dom-island render-dom-lake render-dom-marsh reactive-text reactive-attr reactive-spread reactive-fragment render-list-item extract-key reactive-list bind-input *use-cek-reactive* enable-cek-reactive! cek-reactive-text cek-reactive-attr render-dom-portal render-dom-error-boundary)
+  (begin
+
 (define SVG_NS "http://www.w3.org/2000/svg")
 
 (define MATH_NS "http://www.w3.org/1998/Math/MathML")
@@ -1336,3 +1343,9 @@
                   ((fallback-dom (if (nil? fallback-fn) (let ((el (dom-create-element "div" nil))) (dom-set-attr el "class" "sx-render-error") (dom-set-attr el "style" "color:red;font-size:0.875rem;padding:0.5rem;border:1px solid red;border-radius:0.25rem;margin:0.5rem 0;") (dom-set-text-content el (str "Render error: " err)) el) (if (lambda? fallback-fn) (render-lambda-dom fallback-fn (list err retry-fn) env ns) (render-to-dom (apply fallback-fn (list err retry-fn)) env ns)))))
                   (dom-append container fallback-dom)))))))
       container)))
+
+
+))
+
+;; Re-export to global env
+(import (web adapter-dom))