tanks can spawn and get rendered

TanksServer/Services/TankManager.cs

@@ -0,0 +1,20 @@
+using System.Collections;
+using System.Collections.Concurrent;
+using Microsoft.Extensions.Logging;
+using TanksServer.Models;
+
+namespace TanksServer.Services;
+
+internal sealed class TankManager(ILogger<TankManager> logger) : IEnumerable<Tank>
+{
+    private readonly ConcurrentBag<Tank> _tanks = new();
+
+    public void Add(Tank tank)
+    {
+        logger.LogInformation("Tank added");
+        _tanks.Add(tank);
+    }
+
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+    public IEnumerator<Tank> GetEnumerator() => _tanks.GetEnumerator();
+}