Remove invoke from platform interfaces, add cek-call integration tests

- platform_js.py: remove invoke function definition and PRIMITIVES
  registration, switch domListen handler wrapping to cek-call
- platform_py.py: remove invoke function definition
- run_signal_tests.py: remove invoke patch, use cek_call in batch wrapper
- run_cek_reactive_tests.py: remove invoke, fix primitive lookup to use
  two-level is_primitive/get_primitive, increase recursion limit for
  interpreted CEK evaluation
- test-cek-reactive.sx: add 7 new tests covering cek-call dispatch with
  computed, effect, cleanup, batch coalescing

All 79 tests pass (20 signal + 43 CEK + 16 CEK reactive).

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

shared/sx/ref/run_cek_reactive_tests.py

@@ -6,6 +6,7 @@ import os, sys
 _HERE = os.path.dirname(os.path.abspath(__file__))
 _PROJECT = os.path.abspath(os.path.join(_HERE, "..", "..", ".."))
 sys.path.insert(0, _PROJECT)
+sys.setrecursionlimit(20000)
 
 from shared.sx.parser import parse_all
 from shared.sx.ref import sx_ref
@@ -138,8 +139,8 @@ env["env-merge"] = env_merge
 env["symbol-name"] = lambda s: s.name if isinstance(s, Symbol) else str(s)
 env["keyword-name"] = lambda k: k.name if isinstance(k, Keyword) else str(k)
 env["type-of"] = sx_ref.type_of
-env["primitive?"] = lambda n: n in sx_ref.PRIMITIVES
-env["get-primitive"] = lambda n: sx_ref.PRIMITIVES.get(n)
+env["primitive?"] = sx_ref.is_primitive
+env["get-primitive"] = sx_ref.get_primitive
 env["strip-prefix"] = lambda s, p: s[len(p):] if s.startswith(p) else s
 env["inspect"] = repr
 env["debug-log"] = lambda *args: None
@@ -201,16 +202,6 @@ env["call-thunk"] = lambda f, e: f() if callable(f) else trampoline(eval_expr([f
 env["dict-get"] = lambda d, k: d.get(k, NIL) if isinstance(d, dict) else NIL
 env["identical?"] = lambda a, b: a is b
 
-def _invoke(f, *args):
-    """Call f with args — handles both native callables and SX lambdas."""
-    if isinstance(f, Lambda):
-        return trampoline(sx_ref.call_lambda(f, list(args), env))
-    elif callable(f):
-        return f(*args)
-    return NIL
-
-env["invoke"] = _invoke
-
 # defhandler, defpage, defquery, defaction stubs
 for name in ["sf-defhandler", "sf-defpage", "sf-defquery", "sf-defaction"]:
     pyname = name.replace("-", "_")