Fix concurrent access issues with ConnectedClients

Replaced direct access to GameMain.Server.ConnectedClients with array snapshots in multiple server-side classes to prevent concurrent modification issues during parallel updates. Also updated PhysicsBody and LevelTrigger to avoid static/shared state in parallel contexts, improving thread safety and reliability.

Barotrauma/BarotraumaShared/SharedSource/Map/Levels/LevelObjects/LevelTrigger.cs

@@ -673,13 +673,17 @@ namespace Barotrauma
             }
         }
 
-        private static readonly List<Entity> triggerersToRemove = new List<Entity>();
         public static void RemoveInActiveTriggerers(PhysicsBody physicsBody, HashSet<Entity> triggerers)
         {
             if (physicsBody == null) { return; }
 
-            triggerersToRemove.Clear();
-            foreach (var triggerer in triggerers)
+            // Use local list instead of static field to avoid concurrent access issues during parallel updates
+            var triggerersToRemove = new List<Entity>();
+            
+            // Create snapshot to avoid concurrent modification during enumeration
+            var triggererSnapshot = triggerers.ToArray();
+            
+            foreach (var triggerer in triggererSnapshot)
             {
                 if (triggerer.Removed)
                 {

Barotrauma/BarotraumaShared/SharedSource/Physics/PhysicsBody.cs

@@ -834,6 +834,12 @@ namespace Barotrauma
             if (!IsValidValue(simPosition, "position", -1e10f, 1e10f)) { return false; }
             if (!IsValidValue(rotation, "rotation")) { return false; }
 
+            if (PhysicsBodyQueue.IsInParallelContext)
+            {
+                PhysicsBodyQueue.Enqueue(() => SetTransform(simPosition, rotation, setPrevTransform));
+                return true;
+            }
+
             FarseerBody.SetTransform(simPosition, rotation);
             if (setPrevTransform) { SetPrevTransform(simPosition, rotation); }
             return true;
@@ -848,6 +854,12 @@ namespace Barotrauma
             if (!IsValidValue(simPosition, "position", -1e10f, 1e10f)) { return false; }
             if (!IsValidValue(rotation, "rotation")) { return false; }
 
+            if (PhysicsBodyQueue.IsInParallelContext)
+            {
+                PhysicsBodyQueue.Enqueue(() => SetTransformIgnoreContacts(simPosition, rotation, setPrevTransform));
+                return true;
+            }
+
             FarseerBody.SetTransformIgnoreContacts(ref simPosition, rotation);
             if (setPrevTransform) { SetPrevTransform(simPosition, rotation); }
             return true;