implement beam rendering if shooter or target is already destroyed

src/lib/sim/CombatSystem.cpp

@@ -5,6 +5,8 @@
 #include "Ship.h"
 #include "ShipSystem.h"
 
+static constexpr Tick kWeaponImpactDelayTicks = 5;  // 0.15 s × 30 Hz, rounded to nearest
+
 CombatSystem::CombatSystem(const GameConfig& config)
     : m_config(config)
 {
@@ -71,15 +73,7 @@ void CombatSystem::resolveShipWeapon(Ship& ship, Tick currentTick,
         return;
     }
 
-    // Apply damage to the correct pool.
-    if (ships.findShip(targetId))
-    {
-        ships.damageShip(targetId, w.damage);
-    }
-    else
-    {
-        buildings.damageBuilding(targetId, w.damage);
-    }
+    m_pendingDamage.push_back({targetId, w.damage, currentTick + kWeaponImpactDelayTicks});
 
     FireEvent evt;
     evt.shooter   = ship.id;
@@ -153,14 +147,7 @@ void CombatSystem::resolveStationWeapon(Building& station, Tick currentTick,
         return;
     }
 
-    if (ships.findShip(targetId))
-    {
-        ships.damageShip(targetId, w.damage);
-    }
-    else
-    {
-        buildings.damageBuilding(targetId, w.damage);
-    }
+    m_pendingDamage.push_back({targetId, w.damage, currentTick + kWeaponImpactDelayTicks});
 
     FireEvent evt;
     evt.shooter   = station.id;
@@ -203,6 +190,32 @@ std::optional<EntityId> CombatSystem::acquireStationTarget(
     return best;
 }
 
+void CombatSystem::applyPendingDamage(Tick currentTick,
+                                       ShipSystem& ships,
+                                       BuildingSystem& buildings)
+{
+    auto it = m_pendingDamage.begin();
+    while (it != m_pendingDamage.end())
+    {
+        if (it->appliesAt <= currentTick)
+        {
+            if (ships.findShip(it->target))
+            {
+                ships.damageShip(it->target, it->amount);
+            }
+            else if (buildings.findBuilding(it->target))
+            {
+                buildings.damageBuilding(it->target, it->amount);
+            }
+            it = m_pendingDamage.erase(it);
+        }
+        else
+        {
+            ++it;
+        }
+    }
+}
+
 std::optional<QVector2D> CombatSystem::targetPosition(
     EntityId id,
     const ShipSystem& ships,