WASM kernel fixes: parse, env sync, iterative CEK, click delegation

Browser kernel:
- Add `parse` native fn (matches server: unwrap single, list for multiple)
- Restore env==global_env guard on _env_bind_hook (let bindings must not
  leak to _vm_globals — caused JIT CSSX "Not callable: nil" errors)
- Add _env_bind_hook call in env_set_id so set! mutations sync to VM globals
- Fire _vm_global_set_hook from OP_DEFINE so VM defines sync back to CEK env

CEK evaluator:
- Replace recursive cek_run with iterative while loop using sx_truthy
  (previous attempt used strict Bool true matching, broke in wasm_of_ocaml)
- Remove dead cek_run_iterative function

Web modules:
- Remove find-matching-route and parse-route-pattern stubs from
  boot-helpers.sx that shadowed real implementations from router.sx
- Sync boot-helpers.sx to dist/static dirs for bytecode compilation

Platform (sx-platform.js):
- Set data-sx-ready attribute after boot completes (was only in boot-init
  which sx-platform.js doesn't call — it steps through boot manually)
- Add document-level click delegation for a[sx-get] links as workaround
  for bytecoded bind-event not attaching per-element listeners (VM closure
  issue under investigation — bind-event runs but dom-add-listener calls
  don't result in addEventListener)

Tests:
- New test_kernel.js: 24 tests covering env sync, parse, route matching,
  host FFI/preventDefault, deep recursion
- New navigation test: "sx-get link fetches SX not HTML and preserves layout"
  (currently catches layout breakage after SPA swap — known issue)

Known remaining issues:
- JIT CSSX failures: closure-captured variables resolve to nil in VM bytecode
- SPA content swap via execute-request breaks page layout
- Bytecoded bind-event doesn't attach per-element addEventListener (root
  cause unknown — when listen-target guard appears to block despite element
  being valid)

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

hosts/ocaml/lib/sx_ref.ml

@@ -372,13 +372,17 @@ and sf_provide args env =
 and expand_macro mac raw_args env =
   (let local = (env_merge ((macro_closure (mac))) (env)) in (let () = ignore ((List.iter (fun pair -> ignore ((env_bind local (sx_to_string (first (pair))) (if sx_truthy ((prim_call "<" [(nth (pair) ((Number 1.0))); (len (raw_args))])) then (nth (raw_args) ((nth (pair) ((Number 1.0))))) else Nil)))) (sx_to_list (List (List.mapi (fun i p -> let i = Number (float_of_int i) in (List [p; i])) (sx_to_list (macro_params (mac)))))); Nil)) in (let () = ignore ((if sx_truthy ((macro_rest_param (mac))) then (env_bind local (sx_to_string (macro_rest_param (mac))) (prim_call "slice" [raw_args; (len ((macro_params (mac))))])) else Nil)) in (trampoline ((eval_expr ((macro_body (mac))) (local)))))))
 
-(* cek-run *)
+(* cek-run — iterative to avoid OCaml/WASM stack overflow *)
 and cek_run state =
-  (if sx_truthy ((cek_terminal_p (state))) then (cek_value (state)) else
-   try cek_run ((cek_step (state)))
-   with Eval_error msg ->
-     (if !_last_error_kont = Nil then _last_error_kont := cek_kont state);
-     raise (Eval_error msg))
+  let s = ref state in
+  (try
+    while not (sx_truthy (cek_terminal_p !s)) do
+      s := cek_step !s
+    done;
+    cek_value !s
+  with Eval_error msg ->
+    (if !_last_error_kont = Nil then _last_error_kont := cek_kont !s);
+    raise (Eval_error msg))
 
 (* cek-step *)
 and cek_step state =
@@ -590,19 +594,6 @@ let () = trampoline_fn := (fun v ->
 (* Wire up the primitives trampoline so call_any in HO forms resolves Thunks *)
 let () = Sx_primitives._sx_trampoline_fn := !trampoline_fn
 
-(* Override recursive cek_run with iterative loop.
-   On error, capture the kont from the last state for comp-trace. *)
-let cek_run_iterative state =
-  let s = ref state in
-  (try
-    while not (match cek_terminal_p !s with Bool true -> true | _ -> false) do
-      s := cek_step !s
-    done;
-    cek_value !s
-  with Eval_error msg ->
-    _last_error_kont := cek_kont !s;
-    raise (Eval_error msg))
-
 (* Collect component trace from a kont value *)
 let collect_comp_trace kont =
   let trace = ref [] in

hosts/ocaml/lib/sx_types.ml

@@ -219,9 +219,11 @@ let rec env_get_id env id name =
 let env_get env name = env_get_id env (intern name) name
 
 let rec env_set_id env id v =
-  if Hashtbl.mem env.bindings id then
-    (Hashtbl.replace env.bindings id v; Nil)
-  else
+  if Hashtbl.mem env.bindings id then begin
+    Hashtbl.replace env.bindings id v;
+    (match !_env_bind_hook with Some f -> f env (unintern id) v | None -> ());
+    Nil
+  end else
     match env.parent with
     | Some p -> env_set_id p id v
     | None -> Hashtbl.replace env.bindings id v; Nil

hosts/ocaml/lib/sx_vm.ml

@@ -431,7 +431,9 @@ and run vm =
           let idx = read_u16 frame in
           let name = match consts.(idx) with String s -> s | _ -> "" in
           let v = peek vm in
-          Hashtbl.replace vm.globals name v
+          Hashtbl.replace vm.globals name v;
+          (match !Sx_types._vm_global_set_hook with
+           | Some f -> f name v | None -> ())
 
         (* ---- Inline primitives ----
            Fast path for common types; fallback to actual primitive