HS: return via raise/guard, def param fix, script block extraction

- Compiler: return compiles to (raise (list "hs-return" value))
- Compiler: def wraps body in guard to catch hs-return exceptions
- Compiler: def params extract name from (ref name) nodes
- Test generator: extract <script type="text/hyperscript"> blocks
  and compile def functions as setup before tests
- Test generator: add eval-hs-with-me for {me: N} opts

The return mechanism enables repeat-forever with early exit via return.
Direct SX guard/raise works (returns correct value), but the compiled
HS repeat-forever thunk body needs further debugging for full coverage.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/playwright/generate-sx-tests.py

@@ -25,11 +25,25 @@ with open(INPUT) as f:
 
 # ── HTML parsing ──────────────────────────────────────────────────
 
+def extract_hs_scripts(html):
+    """Extract <script type='text/hyperscript'>...</script> content blocks."""
+    scripts = []
+    for m in re.finditer(
+        r"<script\s+type=['\"]text/hyperscript['\"]>(.*?)</script>",
+        html, re.DOTALL
+    ):
+        scripts.append(m.group(1).strip())
+    return scripts
+
+
 def parse_html(html):
     """Parse HTML into list of element dicts with parent-child relationships.
     Uses Python's html.parser for reliability with same-tag siblings."""
     from html.parser import HTMLParser
 
+    # Remove script tags before parsing elements (they're handled separately)
+    html = re.sub(r"<script\s+type=['\"]text/hyperscript['\"]>.*?</script>", '', html, flags=re.DOTALL)
+
     # Remove | separators
     html = html.replace(' | ', '')
 
@@ -588,10 +602,20 @@ def generate_test_chai(test, elements, var_names, idx):
     actions = parse_action(test['action'], ref)
     checks = parse_checks(test['check'])
 
+    # Extract <script type="text/hyperscript"> blocks
+    hs_scripts = extract_hs_scripts(test.get('html', ''))
+
     lines = []
     lines.append(f'  (deftest "{test["name"]}"')
     lines.append('    (hs-cleanup!)')
 
+    # Compile HS script blocks as setup (def functions etc.)
+    for script in hs_scripts:
+        # Clean whitespace
+        clean = ' '.join(script.split())
+        escaped = clean.replace('\\', '\\\\').replace('"', '\\"')
+        lines.append(f'    (eval-expr-cek (hs-to-sx (hs-compile "{escaped}")))')
+
     bindings = [f'({var_names[i]} (dom-create-element "{el["tag"]}"))' for i, el in enumerate(elements)]
     lines.append(f'    (let ({" ".join(bindings)})')