fix(rules): cure spells damage undead instead of healing

SRD Cure Light Wounds: 'Since undead are powered by negative energy,
this spell deals damage to them instead of curing their wounds. An
undead creature can apply spell resistance, and can attempt a Will save
to take half damage.'

- _apply_heal_effect takes the rolled save; an undead target takes the
  rolled healing as damage (halved on a successful save; SR already
  resolved upstream, DR never applies to spell energy, no bleeding stop
  or stabilization). Living targets are bit-identical.
- cure_light/cure_moderate descriptions fixed: the SRD save line is
  'Will half (harmless)', not 'negates'.
- Deafened 20% verbal spell failure DEFERRED to the README « Limites
  hors perimetre »: SpellSpec carries no components data (would need a
  verbal flag on all 108 spells) and sound-based Perception is not
  modeled either.

tests/test_bleeding_confused.py

@@ -103,7 +103,7 @@ def test_heal_spell_clears_bleed() -> None:
     a.conditions.append(BLEEDING)
     result = eng._apply_heal_effect(
         HealEffect(formula=parse_dice("1d8")), a, caster_level=1,
-        empower=False, maximize=False,
+        empower=False, maximize=False, saved=False,
     )
     assert result == "+5 HP"
     assert a.hp == 55

tests/test_cure_undead.py

@@ -0,0 +1,80 @@
+"""Cure spells damage undead instead of healing (Task 11 conformance).
+
+SRD "Cure Light Wounds" (spells/cure-light-wounds.md): "Since undead are
+powered by negative energy, this spell deals damage to them instead of curing
+their wounds. An undead creature can apply spell resistance, and can attempt
+a Will save to take half damage." The engine resolves SR upstream and the
+rolled Will save halves the damage here; living targets keep healing exactly
+as before.
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from tests.test_spells import _make_caster, _make_engine, _make_target
+
+if TYPE_CHECKING:
+    from pf1e_simulator.models import Combatant
+
+
+def _undead(cid: str = "skeleton", *, hp_max: int = 20) -> Combatant:
+    return _make_target(cid=cid, hp_max=hp_max).model_copy(
+        update={"creature_type": "undead"}
+    )
+
+
+def _caster() -> Combatant:
+    return _make_caster().model_copy(update={"spells": ["Cure Light Wounds"]})
+
+
+class TestCureDamagesUndead:
+    """Given: a level-5 caster (Cure Light Wounds = 1d8+5) and an undead target
+
+    When: the cure spell is delivered
+    Then: the undead takes damage instead of healing.
+    """
+
+    def test_failed_save_deals_full_damage(self) -> None:
+        """Given: an undead at 20 hp
+        When: cured and it fails the Will save (d20=1), the die rolls 8
+        Then: it takes the full 13 damage (8+5) instead of healing."""
+        engine, c, t = _make_engine(
+            _caster(), _undead(), [1, 8], target_pos=(1, 0), target_side="players"
+        )
+        engine._cast_spell(c, t, "Cure Light Wounds")
+        assert t.hp == 7
+        assert any("13 damage (undead)" in line for line in engine._transcript)
+
+    def test_successful_save_halves_the_damage(self) -> None:
+        """Given: an undead at 20 hp
+        When: cured and it succeeds the Will save (natural 20), the die rolls 8
+        Then: it takes half damage (13 // 2 = 6)."""
+        engine, c, t = _make_engine(
+            _caster(), _undead(), [20, 8], target_pos=(1, 0), target_side="players"
+        )
+        engine._cast_spell(c, t, "Cure Light Wounds")
+        assert t.hp == 14
+        assert any("6 damage (undead)" in line for line in engine._transcript)
+
+    def test_undead_destroyed_by_cure_damage(self) -> None:
+        """Given: an undead at 10 hp
+        When: a failed-save cure deals 13 damage
+        Then: the undead is destroyed (undead die at hp <= 0)."""
+        engine, c, t = _make_engine(
+            _caster(), _undead(hp_max=10), [1, 8], target_pos=(1, 0), target_side="players"
+        )
+        engine._cast_spell(c, t, "Cure Light Wounds")
+        assert t.dead is True
+
+    def test_living_target_still_heals(self) -> None:
+        """Given: a living ally at 5/20 hp
+        When: cured with a die roll of 8
+        Then: it heals 13 hp (behavior unchanged for the living)."""
+        engine, c, t = _make_engine(
+            _caster(), _make_target(), [1, 8], target_pos=(1, 0), target_side="players"
+        )
+        t.hp = 5
+        engine._cast_spell(c, t, "Cure Light Wounds")
+        assert t.hp == 18
+        assert any("+13 HP" in line for line in engine._transcript)

tests/test_dying_and_crits.py

@@ -221,7 +221,7 @@ def test_heal_spell_stabilizes_dying_creature() -> None:
     eng._rng = ScriptedRng([1])  # 1d8 -> 1: only 1 point cured
     result = eng._apply_heal_effect(
         HealEffect(formula=parse_dice("1d8")), s, caster_level=1,
-        empower=False, maximize=False,
+        empower=False, maximize=False, saved=False,
     )
     assert result == "+1 HP"
     assert s.hp == -2
@@ -253,7 +253,7 @@ def test_heal_to_positive_hp_does_not_stabilize() -> None:
     eng._rng = ScriptedRng([8])
     eng._apply_heal_effect(
         HealEffect(formula=parse_dice("1d8")), s, caster_level=1,
-        empower=False, maximize=False,
+        empower=False, maximize=False, saved=False,
     )
     assert s.hp == 5
     assert s.stabilized_hp is None