refactor: improve PlaybackModule lifecycle management with onClose

data/playback/src/commonMain/kotlin/bzh/ajaury/chombev/player/di/PlaybackModule.kt

@@ -6,7 +6,10 @@ import org.koin.core.module.Module
 import org.koin.core.module.dsl.bind
 import org.koin.core.module.dsl.singleOf
 import org.koin.dsl.module
+import org.koin.dsl.onClose
 
 val playbackModule: Module = module {
-    singleOf(::PlaybackRepositoryImpl) { bind<PlaybackRepository>() }
+    // Release the audio player when the app is destroyed: closing the composition-scoped Koin drops
+    // this single and fires onClose (only if it was ever created).
+    singleOf(::PlaybackRepositoryImpl) { bind<PlaybackRepository>() } onClose { it?.release() }
 }