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>

tests/playwright/generate-sx-conformance-dev.py

@@ -47,9 +47,56 @@ def parse_js_value(s):
     m = re.match(r'^\[(.+)\]$', s, re.DOTALL)
     if m:
         return parse_js_array(m.group(1))
+    # Empty object
+    if s == '{}':
+        return '{}'
+    # Object literal — convert to SX dict {:key val ...}
+    m = re.match(r'^\{(.+)\}$', s, re.DOTALL)
+    if m:
+        return parse_js_object(m.group(1))
     return None
 
 
+def parse_js_object(inner):
+    """Parse JS object contents into SX dict {:key val ...}. Handles nested."""
+    pairs = split_js_object(inner)
+    if pairs is None:
+        return None
+    sx_pairs = []
+    for pair in pairs:
+        km = re.match(r'\s*["\']?(\w+)["\']?\s*:\s*(.+)$', pair.strip(), re.DOTALL)
+        if not km:
+            return None
+        k = km.group(1)
+        v = parse_js_value(km.group(2).strip())
+        if v is None:
+            return None
+        sx_pairs.append(f':{k} {v}')
+    return '{' + ' '.join(sx_pairs) + '}'
+
+
+def split_js_object(s):
+    """Split JS object-content by commas respecting nesting."""
+    items = []
+    depth = 0
+    current = ''
+    for ch in s:
+        if ch in '([{':
+            depth += 1
+            current += ch
+        elif ch in ')]}':
+            depth -= 1
+            current += ch
+        elif ch == ',' and depth == 0:
+            items.append(current)
+            current = ''
+        else:
+            current += ch
+    if current.strip():
+        items.append(current)
+    return items if items else None
+
+
 def parse_js_array(inner):
     """Parse JS array contents into SX (list ...). Handles nested arrays."""
     items = split_js_array(inner)