Add utils + refacto

Assets/Unheimlich_POC/Scripts/Managers/PortalRoomManager.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using UnityEngine;
+using Unheimlich.Core;
 using Unheimlich.Gameplay.Portals;
 
 namespace Unheimlich.Managers
@@ -9,9 +10,8 @@ namespace Unheimlich.Managers
     /// Monitors player distance to portals and loads/unloads room instances accordingly.
     /// Supports room pooling (keeping inactive rooms in memory) and distance-based activation.
     /// </summary>
-    public class PortalRoomManager : MonoBehaviour
+    public class PortalRoomManager : Singleton<PortalRoomManager>
     {
-        public static PortalRoomManager Instance { get; private set; }
         
         [Header("Settings")]
         [SerializeField] private float _loadDistance = 15f;
@@ -44,16 +44,6 @@ namespace Unheimlich.Managers
             public bool BoundsCalculated = false;
         }
 
-        private void Awake()
-        {
-            if (Instance != null && Instance != this)
-            {
-                Destroy(this);
-                return;
-            }
-            Instance = this;
-        }
-
         private void Start()
         {
             _player = GameObject.FindGameObjectWithTag("Player")?.transform;