feat(engine): refactor resource mgmt & render pipeline

Refactors engine infrastructure for improved resource/service
management and render pipeline extensibility. Replaces World’s
resource API with a service-based API. Splits IGraphicsEngine’s
RenderFrame into BeginFrame/EndFrame. Adds support for pluggable
render pipelines in RenderSystem. Replaces disposed checks with
Debug.Assert in performance paths. Updates RenderExtractionSystem
and render loop for new APIs. Improves diagnostics and code clarity.

BREAKING CHANGE: Resource API replaced with service API; render
pipeline and frame lifecycle interfaces changed.

src/Runtime/Ghost.Entities/Query.cs

@@ -445,8 +445,7 @@ public unsafe partial struct EntityQuery : IDisposable
         return new ChunkIterator(_matchingArchetypes.AsReadOnly(), world);
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public readonly int GetEntityCount()
+    public readonly int CalculateEntityCount()
     {
         var total = 0;
         var world = World.GetWorld(_worldID);

src/Runtime/Ghost.Entities/System.cs

@@ -46,7 +46,7 @@ public abstract class SystemBase : ISystem
         foreach (var queryID in _requiredQueries)
         {
             ref var query = ref World.ComponentManager.GetEntityQueryReference(new Identifier<EntityQuery>(queryID));
-            if (query.GetEntityCount() == 0)
+            if (query.CalculateEntityCount() == 0)
             {
                 return false;
             }

src/Runtime/Ghost.Entities/World.cs

@@ -1,7 +1,6 @@
 using Ghost.Core;
 using Misaki.HighPerformance.Jobs;
 using System.Runtime.CompilerServices;
-using TerraFX.Interop.Windows;
 
 namespace Ghost.Entities;
 
@@ -86,7 +85,7 @@ public partial class World : IDisposable, IEquatable<World>
     private readonly ComponentManager _componentManager;
     private readonly SystemManager _systemManager;
 
-    private readonly Dictionary<Type, object> _globalResource;
+    private readonly Dictionary<Type, object> _services;
 
     private int _version;
     private bool _disposed = false;
@@ -140,7 +139,7 @@ public partial class World : IDisposable, IEquatable<World>
         _componentManager = new ComponentManager(this);
         _systemManager = new SystemManager(this);
 
-        _globalResource = new Dictionary<Type, object>();
+        _services = new Dictionary<Type, object>();
 
         if (jobScheduler != null)
         {
@@ -195,20 +194,20 @@ public partial class World : IDisposable, IEquatable<World>
     /// Registers or overwrites a global resource in the world.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public void SetResource<T>(T resource)
+    public void AddService<T>(T resource)
         where T : class
     {
-        _globalResource[typeof(T)] = resource;
+        _services[typeof(T)] = resource;
     }
 
     /// <summary>
     /// Retrieves a global resource from the world.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public T GetResource<T>()
+    public T GetService<T>()
         where T : class
     {
-        if (_globalResource.TryGetValue(typeof(T), out var resource))
+        if (_services.TryGetValue(typeof(T), out var resource))
         {
             return (T)resource;
         }
@@ -220,10 +219,10 @@ public partial class World : IDisposable, IEquatable<World>
     /// Checks if a global resource exists.
     /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public bool HasResource<T>()
+    public bool HasService<T>()
         where T : class
     {
-        return _globalResource.ContainsKey(typeof(T));
+        return _services.ContainsKey(typeof(T));
     }
 
     public bool Equals(World? other)