Re-organize all projects (#4166)

Content.Server/Projectiles/ProjectileSystem.cs

@@ -0,0 +1,25 @@
+using Content.Server.Projectiles.Components;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
+
+namespace Content.Server.Projectiles
+{
+    [UsedImplicitly]
+    internal sealed class ProjectileSystem : EntitySystem
+    {
+        public override void Update(float frameTime)
+        {
+            base.Update(frameTime);
+
+            foreach (var component in ComponentManager.EntityQuery<ProjectileComponent>(true))
+            {
+                component.TimeLeft -= frameTime;
+
+                if (component.TimeLeft <= 0)
+                {
+                    component.Owner.Delete();
+                }
+            }
+        }
+    }
+}