new: persist preferences across sessions

shared/src/commonMain/kotlin/fr/ajaury/gwenedeg/player/ui/viewmodel/PlayerViewModel.kt

@@ -16,6 +16,7 @@ import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.WhileSubscribed
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.firstOrNull
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 import kotlin.math.roundToInt
@@ -77,8 +78,9 @@ class PlayerViewModel(
         }
     }
 
-    private fun applyCurrentSpeed() {
-        playbackRepository.setSpeed(preferencesRepository.playbackPreferences.value.speed)
+    private suspend fun applyCurrentSpeed() {
+        val playbackPreferences = preferencesRepository.playbackPreferences.firstOrNull() ?: return
+        playbackRepository.setSpeed(playbackPreferences.speed)
     }
 
     fun performMainPlayAction() {
@@ -111,16 +113,22 @@ class PlayerViewModel(
             PlaybackPreferences.MIN_SPEED,
             PlaybackPreferences.MAX_SPEED,
         )
-        preferencesRepository.setPlaybackSpeed(clampedSpeed)
-        playbackRepository.setSpeed(clampedSpeed)
+        viewModelScope.launch {
+            preferencesRepository.setPlaybackSpeed(clampedSpeed)
+            playbackRepository.setSpeed(clampedSpeed)
+        }
     }
 
     fun setShowTranscription(enabled: Boolean) {
-        preferencesRepository.setShowTranscription(enabled)
+        viewModelScope.launch {
+            preferencesRepository.setShowTranscription(enabled)
+        }
     }
 
     fun setShowTranslation(enabled: Boolean) {
-        preferencesRepository.setShowTranslation(enabled)
+        viewModelScope.launch {
+            preferencesRepository.setShowTranslation(enabled)
+        }
     }
 
     fun stop() {