Step 17b: bytecode-compiled text-layout, WASM library import fix

- text-layout.sx added to WASM bytecode pipeline (9K compiled)
- Fix multi-list map calls (map-indexed + nth instead of map fn list1 list2)
- pretext-layout-lines and pretext-position-line moved to library exports
- Browser load-sxbc: handle VmSuspended for import, copy library exports
  to global_env after module load (define-library export fix)
- compile-modules.js: text-layout in SOURCE_MAP, FILES, and entry deps
- Island uses library functions (break-lines, pretext-layout-lines)
  instead of inlining — runs on bytecode VM when exports resolve

Known issue: define-library exports don't propagate to browser global env
yet. The load-sxbc import suspension handler resumes correctly but
bind_import_set doesn't fire. Needs deeper investigation into how the
WASM kernel's define-library registers exports vs how other libraries
(adapter-html, tw) make their exports available.

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

hosts/ocaml/browser/compile-modules.js

@@ -47,6 +47,7 @@ const SOURCE_MAP = {
   'engine.sx': 'web/engine.sx', 'orchestration.sx': 'web/orchestration.sx',
   'boot.sx': 'web/boot.sx',
   'tw-layout.sx': 'web/tw-layout.sx', 'tw-type.sx': 'web/tw-type.sx', 'tw.sx': 'web/tw.sx',
+  'text-layout.sx': 'lib/text-layout.sx',
 };
 let synced = 0;
 for (const [dist, src] of Object.entries(SOURCE_MAP)) {
@@ -79,6 +80,7 @@ const FILES = [
   'page-helpers.sx', 'freeze.sx', 'bytecode.sx', 'compiler.sx', 'vm.sx',
   'dom.sx', 'browser.sx', 'adapter-html.sx', 'adapter-sx.sx', 'adapter-dom.sx',
   'tw-layout.sx', 'tw-type.sx', 'tw.sx',
+  'text-layout.sx',
   'boot-helpers.sx', 'hypersx.sx', 'harness.sx', 'harness-reactive.sx',
   'harness-web.sx', 'engine.sx', 'orchestration.sx',
   // Hyperscript modules — loaded on demand via transparent lazy loader
@@ -478,6 +480,10 @@ if (entryFile) {
   for (const m of HS_LAZY) {
     if (manifest[m] && !lazyDeps.includes(m)) lazyDeps.push(m);
   }
+  // Text layout library — loaded eagerly for Pretext island
+  if (manifest['sx text-layout'] && !eagerDeps.includes('sx text-layout')) {
+    eagerDeps.push('sx text-layout');
+  }
   manifest['_entry'] = {
     file: entryFile.file,
     deps: eagerDeps,