Replace invoke with cek-call in adapters and engine

Completes the invoke→cek-call migration across all spec .sx files:
- adapter-sx.sx: map/filter/for-each in aser wire format
- adapter-dom.sx: island render update-fn
- engine.sx: fetch transform callback
- test-cek-reactive.sx: disposal test

Only async-invoke (adapter-async.sx) remains — separate async pattern.

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

shared/sx/ref/adapter-dom.sx

@@ -1146,7 +1146,7 @@
       (let ((initial (cek-run
                        (make-cek-state expr env
                          (list (make-reactive-reset-frame env update-fn true))))))
-        (invoke update-fn initial)))))
+        (cek-call update-fn (list initial))))))
 
 
 ;; --------------------------------------------------------------------------

shared/sx/ref/adapter-sx.sx

@@ -291,7 +291,7 @@
                      (let ((local (env-merge (lambda-closure f) env)))
                        (env-set! local (first (lambda-params f)) item)
                        (aser (lambda-body f) local))
-                     (invoke f item)))
+                     (cek-call f (list item))))
                  coll))
 
         ;; map-indexed
@@ -304,7 +304,7 @@
                                (env-set! local (first (lambda-params f)) i)
                                (env-set! local (nth (lambda-params f) 1) item)
                                (aser (lambda-body f) local))
-                             (invoke f i item)))
+                             (cek-call f (list i item))))
                          coll))
 
         ;; for-each — evaluate for side effects, aser each body
@@ -317,7 +317,7 @@
                           (let ((local (env-merge (lambda-closure f) env)))
                             (env-set! local (first (lambda-params f)) item)
                             (append! results (aser (lambda-body f) local)))
-                          (invoke f item)))
+                          (cek-call f (list item))))
                       coll)
             (if (empty? results) nil results))
 

shared/sx/ref/engine.sx

@@ -530,7 +530,7 @@
       (if (and env new-html (not (empty? new-html)))
         ;; Parse new content as SX and re-evaluate in island scope
         (let ((parsed (parse new-html)))
-          (let ((sx-content (if transform (invoke transform parsed) parsed)))
+          (let ((sx-content (if transform (cek-call transform (list parsed)) parsed)))
             ;; Dispose old reactive bindings in this marsh
             (dispose-marsh-scope old-marsh)
             ;; Evaluate the SX in a new marsh scope — creates new reactive bindings

shared/sx/ref/sx_ref.py

@@ -2893,11 +2893,11 @@ def aser_special(name, expr, env):
     elif sx_truthy((name == 'map')):
         f = trampoline(eval_expr(first(args), env))
         coll = trampoline(eval_expr(nth(args, 1), env))
-        return map(lambda item: ((lambda local: _sx_begin(_sx_dict_set(local, first(lambda_params(f)), item), aser(lambda_body(f), local)))(env_merge(lambda_closure(f), env)) if sx_truthy(is_lambda(f)) else invoke(f, item)), coll)
+        return map(lambda item: ((lambda local: _sx_begin(_sx_dict_set(local, first(lambda_params(f)), item), aser(lambda_body(f), local)))(env_merge(lambda_closure(f), env)) if sx_truthy(is_lambda(f)) else cek_call(f, [item])), coll)
     elif sx_truthy((name == 'map-indexed')):
         f = trampoline(eval_expr(first(args), env))
         coll = trampoline(eval_expr(nth(args, 1), env))
-        return map_indexed(lambda i, item: ((lambda local: _sx_begin(_sx_dict_set(local, first(lambda_params(f)), i), _sx_dict_set(local, nth(lambda_params(f), 1), item), aser(lambda_body(f), local)))(env_merge(lambda_closure(f), env)) if sx_truthy(is_lambda(f)) else invoke(f, i, item)), coll)
+        return map_indexed(lambda i, item: ((lambda local: _sx_begin(_sx_dict_set(local, first(lambda_params(f)), i), _sx_dict_set(local, nth(lambda_params(f), 1), item), aser(lambda_body(f), local)))(env_merge(lambda_closure(f), env)) if sx_truthy(is_lambda(f)) else cek_call(f, [i, item])), coll)
     elif sx_truthy((name == 'for-each')):
         f = trampoline(eval_expr(first(args), env))
         coll = trampoline(eval_expr(nth(args, 1), env))
@@ -2908,7 +2908,7 @@ def aser_special(name, expr, env):
                 local[first(lambda_params(f))] = item
                 results.append(aser(lambda_body(f), local))
             else:
-                invoke(f, item)
+                cek_call(f, [item])
         if sx_truthy(empty_p(results)):
             return NIL
         else:

shared/sx/ref/test-cek-reactive.sx

@@ -148,7 +148,7 @@
                     true)))))
       ;; Pop scope — call all disposers
       (scope-pop! "sx-island-scope")
-      (for-each (fn (d) (invoke d)) disposers)
+      (for-each (fn (d) (cek-call d nil)) disposers)
       ;; Change signal — no update should fire
       (reset! s 999)
       (assert-equal 0 (len update-calls)))))