HS: extend parser/runtime + new node test runner; ignore test-results/

- Parser: `--` line comments, `|` op, `result` → `the-result`, query-scoped
  `<sel> in <expr>`, `is a/an <type>` predicate, multi-`as` chaining with `|`,
  `match`/`precede` keyword aliases, `[attr]` add/toggle, between attr forms
- Runtime: per-element listener registry + hs-deactivate!, attr toggle
  variants, set-inner-html boots subtree, hs-append polymorphic on
  string/list/element, default? / array-set! / query-all-in / list-set
  via take+drop, hs-script idempotence guard
- Integration: skip reserved (me/it/event/you/yourself) when collecting vars
- Tokenizer: emit `--` comments and `|` op
- Test framework + conformance runner updates; new tests/hs-run-filtered.js
  (single-process Node runner using OCaml VM step-limit to bound infinite
  loops); generate-sx-conformance-dev.py improvements
- mcp_tree.ml + run_tests.ml: harness extensions
- .gitignore: top-level test-results/ (Playwright artifacts)

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

lib/hyperscript/tokenizer.sx

@@ -436,6 +436,8 @@
             (let
               ((ch (hs-cur)) (start pos))
               (cond
+                (and (= ch "-") (< (+ pos 1) src-len) (= (hs-peek 1) "-"))
+                (do (hs-advance! 2) (skip-comment!) (scan!))
                 (and (= ch "/") (< (+ pos 1) src-len) (= (hs-peek 1) "/"))
                 (do (hs-advance! 2) (skip-comment!) (scan!))
                 (and
@@ -613,6 +615,8 @@
                 (do (hs-emit! "op" "\\" start) (hs-advance! 1) (scan!))
                 (= ch ":")
                 (do (hs-emit! "colon" ":" start) (hs-advance! 1) (scan!))
+                (= ch "|")
+                (do (hs-emit! "op" "|" start) (hs-advance! 1) (scan!))
                 :else (do (hs-advance! 1) (scan!)))))))
       (scan!)
       (hs-emit! "eof" nil pos)