Open the joystick via SDL_JoystickOpen() when no GameController mapping exists, fixing d-pad and face button input on devices like the Anbernic retro handheld (GUID not in SDL's database). Handles JOYHATMOTION for d-pad navigation and JOYBUTTONDOWN button 0 for activation. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>