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  compiling — eliminates stale bytecode from out-of-date copies.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/bin/sx_server.ml

@@ -783,6 +783,18 @@ let () =
       if not (Sx_primitives.is_primitive name) then
         Hashtbl.replace _shared_vm_globals name v)
 
+(* Import hook — resolves (import ...) suspensions inside eval_expr/cek_run.
+   Loads the .sx file for the library, registers it, and returns true. *)
+let () =
+  Sx_types._import_hook := Some (fun lib_spec ->
+    let key = Sx_ref.library_name_key lib_spec in
+    if Sx_types.sx_truthy (Sx_ref.library_loaded_p key) then true
+    else match resolve_library_path lib_spec with
+      | Some path ->
+        (try load_library_file path; true
+         with _ -> false)
+      | None -> false)
+
 let make_server_env () =
   let env = make_env () in
   Sx_render.setup_render_env env;

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'),

hosts/ocaml/lib/sx_ref.ml

@@ -488,7 +488,21 @@ and cek_step_loop state =
 
 (* cek-run *)
 and cek_run state =
-  (let final = (cek_step_loop (state)) in (if sx_truthy ((cek_suspended_p (final))) then (raise (Eval_error (value_to_str (String "IO suspension in non-IO context")))) else (cek_value (final))))
+  (let rec run s =
+    let final = cek_step_loop s in
+    if sx_truthy (cek_suspended_p final) then begin
+      let request = cek_io_request final in
+      let op = match request with Dict d -> (match Hashtbl.find_opt d "op" with Some (String s) -> s | _ -> "") | _ -> "" in
+      if op = "import" then
+        let lib_spec = match request with Dict d -> (match Hashtbl.find_opt d "library" with Some v -> v | _ -> Nil) | _ -> Nil in
+        let key = library_name_key lib_spec in
+        let resolved = sx_truthy (library_loaded_p key) ||
+          (match !_import_hook with Some hook -> hook lib_spec | None -> false) in
+        if resolved then run (cek_resume final Nil)
+        else raise (Eval_error "IO suspension in non-IO context")
+      else raise (Eval_error "IO suspension in non-IO context")
+    end else cek_value final
+  in run state)
 
 (* cek-resume *)
 and cek_resume suspended_state result' =
@@ -815,7 +829,26 @@ let cek_run_iterative state =
       s := cek_step !s
     done;
     (match cek_suspended_p !s with
-     | Bool true -> raise (Eval_error "IO suspension in non-IO context")
+     | Bool true ->
+       let request = cek_io_request !s in
+       let op = match request with Dict d -> (match Hashtbl.find_opt d "op" with Some (String s) -> s | _ -> "") | _ -> "" in
+       if op = "import" then begin
+         let lib_spec = match request with Dict d -> (match Hashtbl.find_opt d "library" with Some v -> v | _ -> Nil) | _ -> Nil in
+         let key = library_name_key lib_spec in
+         let resolved = sx_truthy (library_loaded_p key) ||
+           (match !_import_hook with Some hook -> hook lib_spec | None -> false) in
+         if resolved then begin
+           s := cek_resume !s Nil;
+           (* Continue the step loop after resolving the import *)
+           while not (match cek_terminal_p !s with Bool true -> true | _ -> false)
+              && not (match cek_suspended_p !s with Bool true -> true | _ -> false) do
+             s := cek_step !s
+           done;
+           (match cek_suspended_p !s with
+            | Bool true -> raise (Eval_error "IO suspension in non-IO context")
+            | _ -> cek_value !s)
+         end else raise (Eval_error "IO suspension in non-IO context")
+       end else raise (Eval_error "IO suspension in non-IO context")
      | _ -> cek_value !s)
   with Eval_error msg ->
     _last_error_kont_ref := cek_kont !s;