Audio update

src/states/OptionsState.cpp

@@ -2,6 +2,7 @@
 #include "../core/state/StateManager.h"
 #include "../graphics/ui/Font.h"
 #include "../audio/Audio.h"
+#include "../audio/AudioManager.h"
 #include "../audio/SoundEffect.h"
 #include <SDL3/SDL.h>
 #include <algorithm>
@@ -220,7 +221,7 @@ void OptionsState::toggleFullscreen() {
 }
 
 void OptionsState::toggleMusic() {
-    Audio::instance().toggleMute();
+    if (auto sys = ::AudioManager::get()) sys->toggleMute();
     // If muted, music is disabled. If not muted, music is enabled.
     // Note: Audio::instance().isMuted() returns true if muted.
     // But Audio class doesn't expose isMuted directly in header usually?