refactor(scenes): flux centralitzat amb SceneId+ExitRequest; TitleScene attract → LOGO amb fade-to-black

CMakeLists.txt

@@ -94,6 +94,7 @@ set(APP_SOURCES
     source/core/rendering/sprite/animated_sprite_parser.cpp
     source/core/rendering/effects/heat_haze.cpp
     source/core/rendering/transitions/mosaic.cpp
+    source/core/rendering/transitions/fade_to_black.cpp
     source/core/rendering/sdl3gpu/sdl3gpu_shader.cpp
     source/core/rendering/sdl3gpu/viewport.cpp
     source/core/rendering/sdl3gpu/pipelines/crtpi_pipeline.cpp