Fixes invalid pointers to a battle dangling when a battle is removed.

Signed-off-by: Deukhoofd <Deukhoofd@gmail.com>

src/Battling/Models/Battle.hpp

@@ -116,6 +116,18 @@ namespace CreatureLib::Battling {
         const HistoryHolder& GetHistory() const noexcept { return _historyHolder; }
 
         long GetLastTurnTimeMicroseconds() const noexcept { return _lastTurnTime; }
+
+        void EndBattle() {
+            this->_hasEnded = true;
+            for (size_t i = 0; i < _numberOfSides; i++) {
+                auto side = _sides[i];
+                for (auto c : side->GetCreatures()) {
+                    if (c.HasValue()) {
+                        c.GetValue()->ClearBattleData();
+                    }
+                }
+            }
+        }
     };
 }