Initial Video, Render, and Properties implementations.

Co-authored-by: Copilot <copilot@github.com>

test/SDL_headless_fixture.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <SDL3/SDL.h>
+
+#include <cstdlib>
+
+inline void hdk_set_headless_video_driver() {
+#if defined(_WIN32)
+  _putenv_s("SDL_VIDEODRIVER", "dummy");
+#else
+  setenv("SDL_VIDEODRIVER", "dummy", 1);
+#endif
+}
+
+class SDLSession {
+  public:
+    SDLSession() {
+      hdk_set_headless_video_driver();
+      initialized = SDL_Init(SDL_INIT_VIDEO);
+    }
+
+    ~SDLSession() {
+      if (initialized) {
+        SDL_Quit();
+      }
+    }
+
+    bool IsInitialized() const { return initialized; }
+
+  private:
+    bool initialized = false;
+};