ECS refactor: new ComponentSet, serialization, generators

Major ECS API overhaul: added ComponentSet, refactored ComponentRegistry, and updated all entity/component creation methods. Introduced robust custom serialization infrastructure and per-component source generators for registration and (de)serialization. Updated editor, engine, and test code to use new APIs. Improved code quality, naming, and performance throughout. Removed obsolete code and updated dependencies.

Ghost.Engine/IO/CustomSerializer.cs

@@ -0,0 +1,32 @@
+using System.Diagnostics.CodeAnalysis;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace Ghost.Engine.IO;
+
+public class CustomSerializerAttribute : JsonConverterAttribute
+{
+    public CustomSerializerAttribute([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicParameterlessConstructor)] Type serializerType)
+        : base(serializerType)
+    {
+    }
+}
+
+public abstract class CustomSerializer<T> : JsonConverter<T>
+{
+    public sealed override T? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        return DeserializeJson(ref reader, options);
+    }
+
+    public sealed override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
+    {
+        SerializeJson(writer, value, options);
+    }
+
+    public abstract void SerializeJson(Utf8JsonWriter writer, T value, JsonSerializerOptions options);
+    public abstract T? DeserializeJson(ref Utf8JsonReader reader, JsonSerializerOptions options);
+
+    public abstract void SerializeBinary(BinaryWriter writer, T value);
+    public abstract T? DeserializeBinary(BinaryReader reader);
+}