Add hs-htmx module to WASM build — htmx activation was missing

The htmx-boot-subtree! function (defined in lib/hyperscript/htmx.sx)
was never loaded in the browser because hs-htmx.sx wasn't in the
bundle or compile-modules lists. Added to:
- bundle.sh: copy htmx.sx as hs-htmx.sx to dist
- compile-modules.js: compile to hs-htmx.sxbc, add to deps and lazy list

This was the root cause of "Load Content" button not working —
hx-* attributes were never activated because htmx-boot-subtree!
was undefined.

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

hosts/ocaml/browser/bundle.sh

@@ -72,7 +72,7 @@ cp "$ROOT/shared/sx/templates/tw-type.sx"   "$DIST/sx/"
 cp "$ROOT/shared/sx/templates/tw.sx"        "$DIST/sx/"
 
 # 10. Hyperscript
-for f in tokenizer parser compiler runtime integration; do
+for f in tokenizer parser compiler runtime integration htmx; do
   cp "$ROOT/lib/hyperscript/$f.sx" "$DIST/sx/hs-$f.sx"
 done
 

hosts/ocaml/browser/compile-modules.js

@@ -85,7 +85,7 @@ const FILES = [
   'harness-web.sx', 'engine.sx', 'orchestration.sx',
   // Hyperscript modules — loaded on demand via transparent lazy loader
   'hs-tokenizer.sx', 'hs-parser.sx', 'hs-compiler.sx', 'hs-runtime.sx',
-  'hs-integration.sx',
+  'hs-integration.sx', 'hs-htmx.sx',
   'boot.sx',
 ];
 
@@ -456,6 +456,7 @@ for (const file of FILES) {
         'hs-compiler': ['hs-tokenizer', 'hs-parser'],
         'hs-runtime': ['hs-tokenizer', 'hs-parser', 'hs-compiler'],
         'hs-integration': ['hs-tokenizer', 'hs-parser', 'hs-compiler', 'hs-runtime'],
+        'hs-htmx': ['hs-tokenizer', 'hs-parser', 'hs-compiler', 'hs-runtime', 'hs-integration'],
       };
       manifest[key] = {
         file: sxbcFile,
@@ -476,7 +477,7 @@ if (entryFile) {
   const lazyDeps = entryFile.deps.filter(d => LAZY_ENTRY_DEPS.has(d));
   // Hyperscript modules aren't define-library, so not auto-detected as deps.
   // Load them lazily after boot — eager loading breaks the boot sequence.
-  const HS_LAZY = ['hs-tokenizer', 'hs-parser', 'hs-compiler', 'hs-runtime', 'hs-integration'];
+  const HS_LAZY = ['hs-tokenizer', 'hs-parser', 'hs-compiler', 'hs-runtime', 'hs-integration', 'hs-htmx'];
   for (const m of HS_LAZY) {
     if (manifest[m] && !lazyDeps.includes(m)) lazyDeps.push(m);
   }