fix(combat): bound cackle hex extension

src/pf1e_simulator/combat.py

@@ -1396,7 +1396,7 @@ class CombatEngine:
     def _hex_cackle(self, state: CombatantState, target: CombatantState) -> None:
         """Cackle: prolong one hex by 1 round (extends all hex conditions)."""
         extended = False
-        for ac in target.active_conditions:
+        for ac in list(target.active_conditions):
             if ac.source.startswith("hex:"):
                 target.active_conditions.remove(ac)
                 target.active_conditions.append(