chore: Project Restructuring & Theatre

Assets/_Content/Scripts/Core/Managers/Singleton.cs

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+using UnityEngine;
+using System;
+using System.Collections.Generic;
+
+namespace Unheimlich.Core
+{
+    /// <summary>
+    /// Clears all Singleton static instances at the start of every Play Mode session.
+    /// Necessary when Domain Reload is disabled in Enter Play Mode settings.
+    /// </summary>
+    internal static class SingletonRegistry
+    {
+        private static readonly List<Action> _resetCallbacks = new List<Action>();
+
+        public static void Register(Action resetCallback)
+        {
+            if (!_resetCallbacks.Contains(resetCallback))
+                _resetCallbacks.Add(resetCallback);
+        }
+
+        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
+        private static void ResetAll()
+        {
+            foreach (Action reset in _resetCallbacks)
+                reset?.Invoke();
+        }
+    }
+
+    public abstract class Singleton<T> : MonoBehaviour where T : MonoBehaviour
+    {
+        public static T Instance { get; private set; }
+
+        static Singleton()
+        {
+            SingletonRegistry.Register(() => Instance = null);
+        }
+
+        protected virtual void Awake()
+        {
+            if (Instance != null && Instance != this)
+            {
+                Debug.LogWarning($"[{typeof(T).Name}] Multiple instances detected! Destroying duplicate on '{gameObject.name}'.");
+                Destroy(this);
+                return;
+            }
+            Instance = this as T;
+            OnAwake();
+        }
+
+        // Re-registers the instance when entering Play Mode with Scene Reload disabled.
+        // SubsystemRegistration clears Instance before OnEnable runs, so we restore it here.
+        protected virtual void OnEnable()
+        {
+            if (Instance == null)
+                Instance = this as T;
+
+            OnEnabled();
+        }
+
+        protected virtual void OnDestroy()
+        {
+            if (Instance == this)
+            {
+                Instance = null;
+                OnDestroyInstance();
+            }
+        }
+
+        protected virtual void OnAwake() { }
+        protected virtual void OnEnabled() { }
+        protected virtual void OnDestroyInstance() { }
+    }
+}

Assets/_Content/Scripts/Core/Managers/Singleton.cs.meta

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+fileFormatVersion: 2
+guid: 654e642c73c2b954fa86e0caac3f08c1