HS: wait on event basics (+4 tests)

Five parts: (a) tests/hs-run-filtered.js `io-wait-event` mock now
registers a one-shot listener on the target element and resumes with
the event, instead of immediately resuming with nil. (b) Added
hs-wait-for-or runtime form carrying a timeout-ms; mock resumes
immediately when a timeout is present (0ms tests). (c) parser
parse-wait-cmd recognises `wait for EV(v1, v2)` destructure syntax,
emits :destructure list on wait-for AST. (d) compiler emit-wait-for
updated for :from/:or combos; a new `__bind-from-detail__` form
compiles to `(define v (host-get (host-get it "detail") v))`, and the
`do`-sequence handler preprocesses wait-for to splice these synthetic
bindings after the wait. (e) generator extracts `detail: ...` from
`CustomEvent` options so dispatched events carry their payload.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

spec/tests/test-hyperscript-behavioral.sx

@@ -13004,7 +13004,7 @@ end")
       (dom-append (dom-body) _el-div)
       (hs-activate! _el-div)
       (dom-dispatch _el-div "click" nil)
-      (dom-dispatch _el-div "foo" nil)
+      (dom-dispatch _el-div "foo" {:bar "bar"})
       (assert= (dom-text-content _el-div) "bar")
     ))
   (deftest "can wait on event"
@@ -13070,7 +13070,7 @@ end")
       (dom-append (dom-body) _el-div)
       (hs-activate! _el-div)
       (dom-dispatch _el-div "click" nil)
-      (dom-dispatch _el-div "foo" nil)
+      (dom-dispatch _el-div "foo" "hyperscript is hyper cool")
       (assert= (dom-text-content _el-div) "hyperscript is hyper cool")
     ))
 )