WIP Make collections thread-safe and add safe iteration

Replaced static lists and dictionaries with thread-safe ConcurrentDictionary or ThreadLocal collections for various item components and systems. Updated all relevant code to use snapshots (ToArray, ToList) for safe iteration, and added helper methods for marking and clearing changed connections. These changes improve thread safety and prevent potential concurrency issues in multi-threaded scenarios.

Barotrauma/BarotraumaShared/SharedSource/Items/Components/Signal/RelayComponent.cs

@@ -2,6 +2,7 @@
 using Microsoft.Xna.Framework;
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Linq;
 using System.Xml.Linq;
 
@@ -31,7 +32,8 @@ namespace Barotrauma.Items.Components
 
         private float thirdInverseMax = 0, loadEqnConstant = 0;
 
-        private static readonly Dictionary<string, string> connectionPairs = new Dictionary<string, string>
+        // Thread-safe immutable dictionary for connection pairs (read-only after initialization)
+        private static readonly ImmutableDictionary<string, string> connectionPairs = new Dictionary<string, string>
         {
             { "power_in", "power_out"},
             { "signal_in", "signal_out" },
@@ -40,7 +42,7 @@ namespace Barotrauma.Items.Components
             { "signal_in3", "signal_out3" },
             { "signal_in4", "signal_out4" },
             { "signal_in5", "signal_out5" }
-        };
+        }.ToImmutableDictionary();
 
         protected override PowerPriority Priority { get { return PowerPriority.Relay; } }