Bootstrap CEK as default evaluator on both JS and Python sides

SPEC_MODULES + SPEC_MODULE_ORDER for frames/cek in platform_js.py,
PLATFORM_CEK_JS + CEK_FIXUPS_JS constants, auto-inclusion in
run_js_sx.py, 70+ RENAMES in js.sx. Python: CEK always-include in
bootstrap_py.py, eval_expr/trampoline overridden to cek_run in
platform_py.py with _tree_walk_* preserved for test runners.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/sx/ref/js.sx

@@ -214,6 +214,10 @@
   "render-dom-island" "renderDomIsland"
   "reactive-text" "reactiveText"
   "reactive-attr" "reactiveAttr"
+  "cek-reactive-text" "cekReactiveText"
+  "cek-reactive-attr" "cekReactiveAttr"
+  "*use-cek-reactive*" "_useCekReactive"
+  "enable-cek-reactive!" "enableCekReactive"
   "reactive-fragment" "reactiveFragment"
   "reactive-list" "reactiveList"
   "dom-create-element" "domCreateElement"
@@ -520,6 +524,80 @@
   "collect!" "sxCollect"
   "collected" "sxCollected"
   "clear-collected!" "sxClearCollected"
+  "make-cek-continuation" "makeCekContinuation"
+  "continuation-data" "continuationData"
+  "make-cek-state" "makeCekState"
+  "make-cek-value" "makeCekValue"
+  "cek-terminal?" "cekTerminal_p"
+  "cek-run" "cekRun"
+  "cek-step" "cekStep"
+  "cek-control" "cekControl"
+  "cek-env" "cekEnv"
+  "cek-kont" "cekKont"
+  "cek-phase" "cekPhase"
+  "cek-value" "cekValue"
+  "kont-push" "kontPush"
+  "kont-top" "kontTop"
+  "kont-pop" "kontPop"
+  "kont-empty?" "kontEmpty_p"
+  "kont-capture-to-reset" "kontCaptureToReset"
+  "kont-capture-to-reactive-reset" "kontCaptureToReactiveReset"
+  "has-reactive-reset-frame?" "hasReactiveResetFrame_p"
+  "frame-type" "frameType"
+  "make-if-frame" "makeIfFrame"
+  "make-when-frame" "makeWhenFrame"
+  "make-begin-frame" "makeBeginFrame"
+  "make-let-frame" "makeLetFrame"
+  "make-define-frame" "makeDefineFrame"
+  "make-set-frame" "makeSetFrame"
+  "make-arg-frame" "makeArgFrame"
+  "make-call-frame" "makeCallFrame"
+  "make-cond-frame" "makeCondFrame"
+  "make-case-frame" "makeCaseFrame"
+  "make-thread-frame" "makeThreadFrame"
+  "make-map-frame" "makeMapFrame"
+  "make-filter-frame" "makeFilterFrame"
+  "make-reduce-frame" "makeReduceFrame"
+  "make-for-each-frame" "makeForEachFrame"
+  "make-scope-frame" "makeScopeFrame"
+  "make-reset-frame" "makeResetFrame"
+  "make-dict-frame" "makeDictFrame"
+  "make-and-frame" "makeAndFrame"
+  "make-or-frame" "makeOrFrame"
+  "make-dynamic-wind-frame" "makeDynamicWindFrame"
+  "make-reactive-reset-frame" "makeReactiveResetFrame"
+  "make-deref-frame" "makeDerefFrame"
+  "step-eval" "stepEval"
+  "step-continue" "stepContinue"
+  "step-eval-list" "stepEvalList"
+  "step-eval-call" "stepEvalCall"
+  "step-sf-if" "stepSfIf"
+  "step-sf-when" "stepSfWhen"
+  "step-sf-begin" "stepSfBegin"
+  "step-sf-let" "stepSfLet"
+  "step-sf-define" "stepSfDefine"
+  "step-sf-set!" "stepSfSet"
+  "step-sf-and" "stepSfAnd"
+  "step-sf-or" "stepSfOr"
+  "step-sf-cond" "stepSfCond"
+  "step-sf-case" "stepSfCase"
+  "step-sf-thread-first" "stepSfThreadFirst"
+  "step-sf-lambda" "stepSfLambda"
+  "step-sf-scope" "stepSfScope"
+  "step-sf-provide" "stepSfProvide"
+  "step-sf-reset" "stepSfReset"
+  "step-sf-shift" "stepSfShift"
+  "step-sf-deref" "stepSfDeref"
+  "step-ho-map" "stepHoMap"
+  "step-ho-filter" "stepHoFilter"
+  "step-ho-reduce" "stepHoReduce"
+  "step-ho-for-each" "stepHoForEach"
+  "continue-with-call" "continueWithCall"
+  "sf-case-step-loop" "sfCaseStepLoop"
+  "eval-expr-cek" "evalExprCek"
+  "trampoline-cek" "trampolineCek"
+  "reactive-shift-deref" "reactiveShiftDeref"
+  "cond-scheme?" "condScheme_p"
   "scope-push!" "scopePush"
   "scope-pop!" "scopePop"
   "provide-push!" "providePush"