HS: Group 11 misc — toggle-var-cycle, closest-to, tailwind class, toggle timing (+3 tests)

- parser: `toggle $var between v1 and v2 ...` → `(toggle-var-cycle $var (v1 v2 ...))`
- compiler: emit `(hs-toggle-var-cycle! win var-name values)` for new AST node
- runtime: `hs-toggle-var-cycle!` cycles through a list of values on a variable
- parser: `closest .sel to .target` / `closest #id to .target` / `closest sel to .target`
  now consumes the `to` keyword and parses the target expr instead of defaulting to beingTold
- tokenizer: `read-class-name` handles backslash escapes and allows `(`, `)`, `&`
  chars so Tailwind classes like `group-[:nth-of-type(3)_&]:block` tokenize correctly
- platform.py: `domListen` drives async result via `_driveAsync` after `cekCall`
- test: fixed-time toggle asserts `.foo` IS present after click (toggle started, 10ms window open)
- generate-sx-tests.py: aligned MANUAL_TEST_BODIES for timed toggle with corrected assertion

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

shared/static/wasm/sx/hs-compiler.sx

@@ -469,7 +469,8 @@
           (= name "meta")
           (= name "event")
           (= name "it")
-          (= name "result")))
+          (= name "result"))))
+    (define
       emit-for
       (fn
         (ast)
@@ -1806,6 +1807,12 @@
                         (if source (hs-to-sx source) (quote me))
                         event-name)
                       (list (quote hs-toggle-class!) tgt cls))))
+                ((= head (quote toggle-var-cycle))
+                  (list
+                    (quote hs-toggle-var-cycle!)
+                    (list (quote host-global) "window")
+                    (nth ast 1)
+                    (cons (quote list) (map hs-to-sx (nth ast 2)))))
                 ((= head (quote set-on))
                   (list
                     (quote hs-set-on!)