feat(config): persistència de les opcions d'àudio al config.yaml

source/core/config/engine_config.hpp

@@ -56,9 +56,19 @@ namespace Config {
         std::string gamepad_name;  // Empty = auto-assign by index
     };
 
+    struct AudioConfig {
+        bool enabled{true};
+        float volume{1.0F};  // Master 0..1
+        bool music_enabled{true};
+        float music_volume{1.0F};
+        bool sound_enabled{true};
+        float sound_volume{0.25F};
+    };
+
     struct EngineConfig {
         WindowConfig window{};
         RenderingConfig rendering{};
+        AudioConfig audio{};
         PlayerBindings player1{};
         PlayerBindings player2{};
         KeyboardBindings keyboard_controls{};  // Defaults globals per Input