Refactor project management and enhance architecture

Added a new static class `AssetsPath` for asset management.
Added a new icon file (`icon-256.ico`) for UI representation.
Added new package references to enhance functionality.
Added internals visibility attributes for better testing.
Added a new `EngineEditorViewModel` class for MVVM support.
Added a new `GameObject` class for component management.
Added a new `BitSet` class for efficient bit manipulation.
Added various utility classes to support the new entity system.

Changed the `ID` property in `ProjectInfo` to internal.
Changed the `AddProjectAsync` method to return the created `ProjectInfo`.
Changed the connection string retrieval method to use the new `Command` constant.
Changed the `DataPath` class to use `readonly` fields for folder paths.
Changed the `ActivationHandler` class to use new `DataPath` constants.
Changed the `OpenProjectPage` layout and interaction for better UI.

Updated the target framework to a newer version for compatibility.
Updated the `ProjectService` to use new constants from `DataPath`.
Updated the `World` class to improve entity management.

Refactored the `ProjectRepository` class to encapsulate SQL commands.
Refactored the `Transform` class to use properties for better encapsulation.

Ghost.Entities/Component.cs

@@ -0,0 +1,103 @@
+using Ghost.Entities.Helpers;
+using Ghost.Entities.Registries;
+using Misaki.HighPerformance.Unsafe.Collections;
+using Misaki.HighPerformance.Unsafe.Helpers;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace Ghost.Entities;
+
+public interface IComponent
+{
+
+}
+
+[SkipLocalsInit]
+internal readonly record struct ComponentData
+{
+    public readonly int id;
+    public readonly int sizeInByte;
+
+    public ComponentData(int id, int sizeInByte)
+    {
+        this.id = id;
+        this.sizeInByte = sizeInByte;
+    }
+}
+
+internal static class Component
+{
+    public static unsafe UnsafeArray<int> ToLookupArray(Span<ComponentData> datas, Allocator allocator)
+    {
+        var max = 0;
+        foreach (var data in datas)
+        {
+            var componentId = data.id;
+            if (componentId >= max)
+            {
+                max = componentId;
+            }
+        }
+
+        // Create lookup table where the component ID points to the component index.
+        var array = new UnsafeArray<int>(max + 1, allocator);
+        array.AsSpan().Fill(-1);
+
+        for (var index = 0; index < datas.Length; index++)
+        {
+            ref var type = ref datas[index];
+            var componentId = type.id;
+            array[componentId] = index;
+        }
+
+        return array;
+    }
+
+    public static int GetHashCode(Span<ComponentData> components)
+    {
+        // Search for the highest id to determine how much uints we need for the stack.
+        var highestId = 0;
+        foreach (ref var cmp in components)
+        {
+            if (cmp.id > highestId)
+            {
+                highestId = cmp.id;
+            }
+        }
+
+        // Allocate the stack and set bits to replicate a bitset
+        var length = BitSet.RequiredLength(highestId + 1);
+        Span<uint> stack = stackalloc uint[length];
+        var spanBitSet = new SpanBitSet(stack);
+
+        foreach (ref var type in components)
+        {
+            var x = type.id;
+            spanBitSet.SetBit(x);
+        }
+
+        return GetHashCode(stack);
+    }
+
+    public static int GetHashCode(Span<uint> span)
+    {
+        var hashCode = new HashCode();
+        hashCode.AddBytes(MemoryMarshal.AsBytes(span));
+
+        return hashCode.ToHashCode();
+    }
+}
+
+internal static class Component<T>
+    where T : unmanaged, IComponent
+{
+    public static readonly ComponentData data;
+
+    public static readonly Signature signature;
+
+    static Component()
+    {
+        data = ComponentRegistry.GetOrAdd<T>();
+        signature = new Signature(data);
+    }
+}