chore: remove all graphics backends (Raylib, OpenTK, Vulkan/Silk.NET) — prepare for pure Vulkan P/Invoke rewrite

src/Engine.Graphics.Vulkan/VulkanRenderContext.cs

@@ -1,35 +0,0 @@
-using Engine.Core;
-using Engine.Graphics;
-
-namespace Engine.Graphics.Vulkan;
-
-/// <summary>
-/// Vulkan implementation of the render HAL context.
-/// Creates and owns an <see cref="Sdl3Window"/> for the Vulkan surface.
-/// </summary>
-public sealed class VulkanRenderContext : IRenderContext
-{
-    private readonly Sdl3Window _window;
-    private readonly VulkanContext _context;
-    private readonly Swapchain _swapchain;
-
-    public IWindow Window => _window;
-
-    public VulkanRenderContext(int width, int height, bool enableValidation)
-    {
-        _window = new Sdl3Window("Cortex Engine", width, height, vulkanSurface: true);
-        _context = new VulkanContext(_window, enableValidation);
-        _swapchain = new Swapchain(_context);
-    }
-
-    public IRenderer CreateRenderer() => new VulkanRenderer(_context, _swapchain);
-
-    public void Resize(int width, int height) => _swapchain.Recreate(width, height);
-
-    public void Dispose()
-    {
-        _swapchain.Dispose();
-        _context.Dispose();
-        _window.Dispose();
-    }
-}