Tests: cek-try-seq / htmx / hs-diag / perform-chain + node HS runners

New spec tests: test-cek-try-seq (CEK try/seq), test-htmx (htmx
directive coverage, 292L), test-hs-diag, test-perform-chain (IO
suspension chains).

tests/hs-*.js: Node.js-side hyperscript runners for browser-mode
testing (hs-behavioral-node, hs-behavioral-runner, hs-parse-audit,
hs-run-timed).

Vendors shared/static/scripts/htmx.min.js.

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

spec/tests/test-hs-diag.sx

@@ -0,0 +1,17 @@
+(defsuite
+  "hs-diag"
+  (deftest
+    "put into #id compiled"
+    (let
+      ((sx (hs-to-sx-from-source "on click put \"foo\" into #d1")))
+      (assert= (serialize sx) "SHOW")))
+  (deftest
+    "put into #id works"
+    (let
+      ((el (dom-create-element "div")))
+      (dom-set-attr el "id" "d1")
+      (dom-set-attr el "_" "on click put \"foo\" into #d1")
+      (dom-append (dom-body) el)
+      (hs-activate! el)
+      (dom-dispatch el "click" nil)
+      (assert= (dom-text-content el) "foo"))))