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  compiling — eliminates stale bytecode from out-of-date copies.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;