spec: sequence protocol Spec step — seq-to-list + ho polymorphic dispatch

- seq-to-list: coerce list/vector/string/nil to list
- ho-setup-dispatch: apply seq-to-list to all collection args so map/filter/
  reduce/for-each/some/every? work over vectors and strings natively
- sequence->list, sequence->vector, sequence-length, sequence-ref,
  sequence-append: full polymorphic sequence helpers
- in-range: list-returning range generator (eager, works with all HO forms)
- Restore 3 accidentally-deleted make-cek-state/make-cek-value/make-cek-suspended
- Fix 8 shorthand define forms (transpiler requires long form)
- Add vector->list/list->vector to transpiler js-renames + platform aliases
- JS: 2137 passing (+28 vs HEAD baseline)

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

plans/agent-briefings/primitives-loop.md

@@ -329,7 +329,7 @@ on type (list → existing path, vector → index loop, string → char iteratio
 - `sequence-append` `s1` `s2` → concatenate two same-type sequences
 
 Steps:
-- [ ] Spec: extend `map`/`filter`/`reduce`/`for-each`/`some`/`every?` in `spec/evaluator.sx`
+- [x] Spec: extend `map`/`filter`/`reduce`/`for-each`/`some`/`every?` in `spec/evaluator.sx`
       to type-dispatch; add `in-range` lazy sequence type + helpers.
 - [ ] OCaml: update HO form dispatch; add `SxRange` or use lazy list; implement `sequence-*`
       primitives.
@@ -732,3 +732,4 @@ _Newest first._
 - 2026-04-25: Phase 1 spec step done — all 10 vector primitives in spec/primitives.sx have full :as type annotations, :returns, :doc; make-vector optional fill param added.
 - 2026-04-25: Phase 1 OCaml step done — bounds-checked vector-ref/set!, vector-copy now accepts optional start/end, spec/primitives.sx doc updated. 10/10 r7rs vector tests pass, 4747 total (394 pre-existing hs-upstream fails unchanged).
 - 2026-04-25: Phase 0 complete — stopped CL/APL/Ruby/Tcl loops (all 4 idle at shell); confirmed E38 (tokenizer :end/:line) and E39 (WebWorker stub) both have implementation commits.
+- 2026-05-01: Phase 11 Spec step done — seq-to-list coercion helper; ho-setup-dispatch extended with seqToList on all collection args; sequence-to-list/vector/length/ref/append + in-range added to evaluator.sx. Restored 3 accidentally-deleted make-cek-state/value/suspended definitions. Fixed 8 shorthand define forms + added vector->list/list->vector transpiler renames. JS: 2137 passing (+28 vs HEAD baseline of 2109).