fix: add safe erasing in loops

src/game/Mobs.cpp

@@ -33,11 +33,11 @@ void Mob::tick(std::uint64_t delta) {
 
 void Mob::updateEffects(std::uint64_t delta) {
     float deltaSec = (float)delta / 1000.0f;
-    for (auto it = m_Effects.begin(); it != m_Effects.end(); it++) {
-        EffectDuration& effect = *it;
+    for (std::size_t i = 0; i < m_Effects.size(); i++) {
+        EffectDuration& effect = m_Effects[i];
         effect.second -= deltaSec;
         if (effect.second < 0)   // effect has gone
-            m_Effects.erase(it);
+            m_Effects.erase(m_Effects.begin() + i);
     }
 }