HS: hide strategy config (+3 tests)

Three parts: (a) `runtime.sx` hs-hide-one!/hs-show-one! consult a new
`_hs-hide-strategies` dict (and `_hs-default-hide-strategy` override)
before falling through to the built-in display/opacity/etc. cases. The
strategy fn is called directly with (op, el, arg). New setters
`hs-set-hide-strategies!` and `hs-set-default-hide-strategy!`. (b)
`generate-sx-tests.py` `_hs_config_setup_ops` recognises
`_hyperscript.config.defaultHideShowStrategy = "X"`, `delete …default…`,
and `hideShowStrategies = { NAME: function (op, el, arg) { if …
classList.add/remove } }` with brace-matched function body extraction.
(c) Pre-setup emitter handles `__hs_config__` pseudo-name by emitting
the SX expression as-is (not a window.X = Y assignment).

Suite hs-upstream-hide: 12/16 → 15/16. Remaining test
(`hide element then show element retains original display`) needs
`on click 1 hide` / `on click 2 show` count-filtered events — separate
feature. Smoke 0-195: 162/195 unchanged.

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

tests/playwright/generate-sx-tests.py

@@ -783,6 +783,58 @@ def _window_setup_ops(assign_body):
     return out
 
 
+def _hs_config_setup_ops(body):
+    """Translate `_hyperscript.config.X = ...` assignments into SX ops.
+    Recognises `defaultHideShowStrategy = "name"` and `hideShowStrategies = { NAME: fn }`
+    for simple classList.add/remove-based strategies. Returns list of SX expr strings.
+    Empty list means no recognised ops; caller should skip (don't drop the block)."""
+    ops = []
+    # defaultHideShowStrategy = "name"
+    for dm in re.finditer(
+        r'_hyperscript\.config\.defaultHideShowStrategy\s*=\s*"([^"]+)"',
+        body,
+    ):
+        ops.append(f'(hs-set-default-hide-strategy! "{dm.group(1)}")')
+    for dm in re.finditer(
+        r"_hyperscript\.config\.defaultHideShowStrategy\s*=\s*'([^']+)'",
+        body,
+    ):
+        ops.append(f'(hs-set-default-hide-strategy! "{dm.group(1)}")')
+    # delete _hyperscript.config.defaultHideShowStrategy
+    if re.search(r'delete\s+_hyperscript\.config\.defaultHideShowStrategy', body):
+        ops.append('(hs-set-default-hide-strategy! nil)')
+    # hideShowStrategies = { NAME: function(op, element, arg) { IF-ELSE } }
+    # Nested braces — locate the function body by manual brace-matching.
+    sm = re.search(
+        r'_hyperscript\.config\.hideShowStrategies\s*=\s*\{\s*'
+        r'(\w+)\s*:\s*function\s*\(\s*\w+\s*,\s*\w+\s*,\s*\w+\s*\)\s*\{',
+        body,
+    )
+    if sm:
+        name = sm.group(1)
+        start = sm.end()
+        depth = 1
+        i = start
+        while i < len(body) and depth > 0:
+            if body[i] == '{': depth += 1
+            elif body[i] == '}': depth -= 1
+            i += 1
+        fn_body = body[start:i - 1] if depth == 0 else ''
+        hm = re.search(
+            r'if\s*\(\s*\w+\s*==\s*"hide"\s*\)\s*\{\s*'
+            r'\w+\.classList\.add\(\s*"([^"]+)"\s*\)\s*;?\s*\}\s*'
+            r'else\s*\{\s*\w+\.classList\.remove\(\s*"([^"]+)"\s*\)\s*;?\s*\}',
+            fn_body, re.DOTALL,
+        )
+        if hm:
+            cls = hm.group(1)
+            ops.append(
+                f'(hs-set-hide-strategies! {{:{name} '
+                f'(fn (op el arg) (if (= op "hide") (dom-add-class el "{cls}") (dom-remove-class el "{cls}")))}})'
+            )
+    return ops
+
+
 def _extract_detail_expr(opts_src):
     """Extract `detail: ...` from an event options block like `, { detail: X }`.
     Returns an SX expression string, defaulting to `nil`."""
@@ -920,8 +972,29 @@ def parse_dev_body(body, elements, var_names):
                     else:
                         pre_setups.append((name, sx_val))
                 continue
+            # _hyperscript.config.X = ... setups (hideShowStrategies etc.)
+            hs_config_ops = _hs_config_setup_ops(m.group(1))
+            if hs_config_ops:
+                for op_expr in hs_config_ops:
+                    if seen_html:
+                        ops.append(op_expr)
+                    else:
+                        pre_setups.append(('__hs_config__', op_expr))
+                continue
             # fall through
 
+        # evaluate(() => _hyperscript.config.X = ...) single-line variant.
+        m = re.match(r'evaluate\(\s*\(\)\s*=>\s*(_hyperscript\.config\..+?)\s*\)\s*$', stmt_na, re.DOTALL)
+        if m:
+            hs_config_ops = _hs_config_setup_ops(m.group(1))
+            if hs_config_ops:
+                for op_expr in hs_config_ops:
+                    if seen_html:
+                        ops.append(op_expr)
+                    else:
+                        pre_setups.append(('__hs_config__', op_expr))
+                continue
+
         # evaluate(() => document.querySelector(SEL).innerHTML = VAL) — DOM reset.
         m = re.match(
             r"evaluate\(\s*\(\)\s*=>\s*document\.querySelector\(\s*(['\"])([^'\"]+)\1\s*\)"
@@ -1215,7 +1288,10 @@ def generate_test_pw(test, elements, var_names, idx):
     # Pre-`html(...)` setups — emit before element creation so activation
     # (init handlers etc.) sees the expected globals.
     for name, sx_val in pre_setups:
-        lines.append(f'    (host-set! (host-global "window") "{name}" {sx_val})')
+        if name == '__hs_config__':
+            lines.append(f'    {sx_val}')
+        else:
+            lines.append(f'    (host-set! (host-global "window") "{name}" {sx_val})')
 
     # Compile script blocks so `def X()` functions are available. Wrap in
     # guard because not all script forms (e.g. `behavior`) are implemented