test(validation): scope list_mod_check like GenericObject._verify_slot

The framework-tier harness in test_included_stateful.py set
obj.list_mod_check = True for the whole detached-ask block and reset it
to a literal False afterward, instead of scoping it to just the
included() call and restoring the ORIGINAL value the way
GenericObject._verify_slot does. Mirror the real method's finally
discipline. Also make tests.matrix_support.allows_other_modifiers
delegate to GenericObject._allows_other_modifiers instead of
re-implementing the attribute-vs-method split, the same way hdc_id
delegates to obj.hdc_id().

No engine logic changes; 77/77 focused tests still pass.

Author: pdbethke

tests/matrix_support.py

@@ -131,11 +131,11 @@ def hdc_id(obj) -> str:
 
 
 def allows_other_modifiers(obj) -> bool:
-    """``GenericObject.allows_other_modifiers`` is a bool attribute on the
-    base class but a METHOD override on a handful of subclasses (martial
-    arts elements, ``Disadvantage``) -- call it if callable, else read it."""
-    val = obj.allows_other_modifiers
-    return val() if callable(val) else val
+    """Delegates to the library's own ``GenericObject._allows_other_modifiers``
+    (base.py) -- that is the one accessor for the attribute-vs-method split
+    (a bool attribute on the base class, a METHOD override on a handful of
+    subclasses: martial arts elements, ``Disadvantage``), same as ``hdc_id``."""
+    return GenericObject._allows_other_modifiers(obj)
 
 
 @lru_cache(maxsize=1)

tests/test_included_stateful.py

@@ -65,17 +65,20 @@ def _ask(cell: dict, index: dict) -> tuple[bool, str]:
         with_siblings = list(orig_assigned) + [m for m in missing if m is not mod]
 
         orig_obj_parent = obj.parent
+        orig_check = obj.list_mod_check
         obj.assigned_modifiers = with_siblings
         obj.parent = None
         if compound_id:
             compound.parent = None
-        obj.list_mod_check = True
         try:
             if not allows_other_modifiers(obj):
                 return False, f"{obj.alias} does not allow modifiers with its current configuration."
-            reason = mod.included(obj) or ""
+            obj.list_mod_check = True      # GenericObject._verify_slot: around the ask only
+            try:
+                reason = mod.included(obj) or ""
+            finally:
+                obj.list_mod_check = orig_check
         finally:
-            obj.list_mod_check = False
             obj.assigned_modifiers = orig_assigned
             obj.parent = orig_obj_parent
             if compound_id: