Fix server import suspension, dist sync, JIT errors

- cek_run patched to handle import suspensions via _import_hook.
  define-library (import ...) now resolves cleanly on the server.
  IO suspension errors: 190 → 0. JIT failures: ~50 → 0.
- _import_hook wired in sx_server.ml to load .sx files on demand.
- compile-modules.js syncs source .sx files to dist/sx/ before
  compiling — eliminates stale bytecode from out-of-date copies.
- WASM binary rebuilt with all fixes.
- 2658/2658 tests pass (8 new — previously failing import tests).

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

hosts/ocaml/browser/compile-modules.js

@@ -16,12 +16,53 @@ const { execSync, spawnSync } = require('child_process');
 
 const distDir = process.argv[2] || path.join(__dirname, 'dist');
 const sxDir = path.join(distDir, 'sx');
+const projectRoot = path.resolve(__dirname, '..', '..', '..');
 
 if (!fs.existsSync(sxDir)) {
   console.error('sx dir not found:', sxDir);
   process.exit(1);
 }
 
+// Sync source .sx files to dist/sx/ before compiling.
+// Source locations: spec/ for core, lib/ for compiler/vm, web/ and web/lib/ for web stack.
+const SOURCE_MAP = {
+  // spec/
+  'render.sx': 'spec/render.sx',
+  'core-signals.sx': 'spec/signals.sx',
+  // lib/
+  'bytecode.sx': 'lib/bytecode.sx', 'compiler.sx': 'lib/compiler.sx',
+  'vm.sx': 'lib/vm.sx', 'freeze.sx': 'lib/freeze.sx',
+  'highlight.sx': 'lib/highlight.sx',
+  // web/lib/
+  'dom.sx': 'web/lib/dom.sx', 'browser.sx': 'web/lib/browser.sx',
+  // web/
+  'signals.sx': 'web/signals.sx', 'deps.sx': 'web/deps.sx',
+  'router.sx': 'web/router.sx', 'page-helpers.sx': 'web/page-helpers.sx',
+  'adapter-html.sx': 'web/adapter-html.sx', 'adapter-sx.sx': 'web/adapter-sx.sx',
+  'adapter-dom.sx': 'web/adapter-dom.sx',
+  'boot-helpers.sx': 'web/lib/boot-helpers.sx',
+  'hypersx.sx': 'web/hypersx.sx',
+  'harness.sx': 'spec/harness.sx', 'harness-reactive.sx': 'web/harness-reactive.sx',
+  'harness-web.sx': 'web/harness-web.sx',
+  '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',
+};
+let synced = 0;
+for (const [dist, src] of Object.entries(SOURCE_MAP)) {
+  const srcPath = path.join(projectRoot, src);
+  const dstPath = path.join(sxDir, dist);
+  if (fs.existsSync(srcPath)) {
+    const srcContent = fs.readFileSync(srcPath);
+    const dstExists = fs.existsSync(dstPath);
+    if (!dstExists || !fs.readFileSync(dstPath).equals(srcContent)) {
+      fs.writeFileSync(dstPath, srcContent);
+      synced++;
+    }
+  }
+}
+if (synced > 0) console.log('Synced ' + synced + ' source files to dist/sx/');
+
 // Find the native OCaml binary
 const binPaths = [
   path.join(__dirname, '..', '_build', 'default', 'bin', 'sx_server.exe'),