desktop code refactoring

Signed-off-by: Peter Siegmund <developer@mars3142.org>

src/model/Window.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "SDL3/SDL.h"
+
+class Window {
+public:
+    explicit Window(SDL_Window* window)
+        : m_window(window) {
+    }
+
+    [[nodiscard]] auto window() const -> SDL_Window*;
+
+    [[nodiscard]] auto renderer() const -> SDL_Renderer*;
+
+private:
+    SDL_Window* m_window = nullptr;
+};