feat: Implement lazy initialization for Emulator and Renderer

- Updated Emulator to support optional lazy initialization of the renderer, enhancing flexibility during runtime.
- Introduced a new method in IRenderer for creating textures with specific pixel formats, improving texture management for the emulator.
- Refactored texture command processing in Arena to handle empty queues more gracefully.
- Enhanced SDL2Renderer to support the new texture creation method, ensuring compatibility with emulator requirements.

src/app/gfx/arena.cc

@@ -33,7 +33,7 @@ void Arena::QueueTextureCommand(TextureCommandType type, Bitmap* bitmap) {
 }
 
 void Arena::ProcessTextureQueue(IRenderer* renderer) {
-  if (!renderer_) return;
+  if (!renderer_ || texture_command_queue_.empty()) return;
 
   for (const auto& command : texture_command_queue_) {
     switch (command.type) {

src/app/gfx/backend/irenderer.h

@@ -60,6 +60,16 @@ public:
      */
     virtual TextureHandle CreateTexture(int width, int height) = 0;
 
+    /**
+     * @brief Creates a new texture with a specific pixel format.
+     * @param width The width of the texture in pixels.
+     * @param height The height of the texture in pixels.
+     * @param format The SDL pixel format (e.g., SDL_PIXELFORMAT_ARGB8888).
+     * @param access The texture access pattern (e.g., SDL_TEXTUREACCESS_STREAMING).
+     * @return An abstract TextureHandle to the newly created texture, or nullptr on failure.
+     */
+    virtual TextureHandle CreateTextureWithFormat(int width, int height, uint32_t format, int access) = 0;
+
     /**
      * @brief Updates a texture with the pixel data from a Bitmap.
      * @param texture The handle of the texture to update.

src/app/gfx/backend/sdl2_renderer.cc

@@ -50,6 +50,16 @@ TextureHandle SDL2Renderer::CreateTexture(int width, int height) {
     );
 }
 
+/**
+ * @brief Creates an SDL_Texture with a specific pixel format and access pattern.
+ * This is useful for specialized textures like emulator PPU output.
+ */
+TextureHandle SDL2Renderer::CreateTextureWithFormat(int width, int height, uint32_t format, int access) {
+    return static_cast<TextureHandle>(
+        SDL_CreateTexture(renderer_.get(), format, access, width, height)
+    );
+}
+
 /**
  * @brief Updates an SDL_Texture with data from a Bitmap.
  * This involves converting the bitmap's surface to the correct format and updating the texture.

src/app/gfx/backend/sdl2_renderer.h

@@ -26,6 +26,7 @@ public:
 
     // --- Texture Management ---
     TextureHandle CreateTexture(int width, int height) override;
+    TextureHandle CreateTextureWithFormat(int width, int height, uint32_t format, int access) override;
     void UpdateTexture(TextureHandle texture, const Bitmap& bitmap) override;
     void DestroyTexture(TextureHandle texture) override;