Refactor asset streaming & resource management system

- Introduce Ghost.Engine.Streaming namespace and split asset entry logic into type-specific classes (TextureAssetEntry, MeshAssetEntry, SceneAssetEntry)
- Make AssetEntry abstract; add AssetEntryFactory for type dispatch
- Update AssetManager and ResourceStreamingProcessor for new entry model, supporting uploadable and processable assets
- Redesign scene/mesh asset loading, serialization, and binary formats with versioning (SceneContentHeader, MeshContentHeader)
- Move SceneLoadingType to Ghost.Engine and make public
- Inline performance-critical APIs with MethodImplOptions.AggressiveInlining
- Add deep cloning and improved resource management for Mesh and meshlet data
- Allow nullable log messages in Logger
- Update Misaki.HighPerformance package references
- Remove obsolete files (Asset.cs, ActivationHandler.cs, old mesh logic)
- Improve resource release logic in ResourceManager
- Update RenderContext and ResourceStreamingContext for new streaming model
- Add UnsafeArray/UnsafeList clone utilities
- Update scene serialization/deserialization for new format
- Update tests for new APIs, asset states, and formats

src/Runtime/Ghost.Core/Common.cs

@@ -1,9 +1,21 @@
 namespace Ghost.Core;
 
+public interface ICloneable<T>
+    where T : ICloneable<T>
+{
+    /// <summary>
+    /// Deep copy the object to create a new instance that contains the same value.
+    /// </summary>
+    /// <remarks>
+    /// This often does not clone any gpu resources if the object holds any.
+    /// </remarks>
+    T Clone();
+}
+
 public class Wrapper<T>
 {
     public T? Value
     {
         get; set;
     }
-}
+}