Move defstyle/deftype/defeffect to web-forms.sx — domain forms, not core

These are domain definition forms (same pattern as defhandler, defpage,
etc.), not core language constructs. Moving them to web-forms.sx keeps
the core evaluator + types.sx cleaner for WASM compilation.

web-forms.sx now loaded in both JS and Python build pipelines.

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

hosts/javascript/bootstrap.py

@@ -136,6 +136,7 @@ def compile_ref_to_js(
         ("freeze.sx", "freeze (serializable state boundaries)"),
         ("content.sx", "content (content-addressed computation)"),
         ("render.sx", "render (core)"),
+        ("web-forms.sx", "web-forms (defstyle, deftype, defeffect, defrelation)"),
     ]
     for name in ("parser", "html", "sx", "dom", "engine", "orchestration", "boot"):
         if name in adapter_set: