Challenge 2: A Settings Repository with Hilt — Solution

class SettingsRepository @Inject constructor(
    @ApplicationContext private val context: Context
) {
    val notificationsEnabled: Flow<Boolean> = context.dataStore.data
        .map { prefs -> prefs[PreferencesKeys.NOTIFICATIONS_ENABLED] ?: true }

    suspend fun setNotificationsEnabled(enabled: Boolean) {
        context.dataStore.edit { prefs ->
            prefs[PreferencesKeys.NOTIFICATIONS_ENABLED] = enabled
        }
    }
}

Notes:
- @ApplicationContext private val context: Context is the same
  Hilt-provided qualifier used in Chapter 5's DatabaseModule — it
  guarantees this repository holds an app-scoped Context (which safely
  lives as long as the app does), not a shorter-lived Activity Context
  that could leak or become invalid.
- Because SettingsRepository has an @Inject constructor and Hilt already
  knows how to provide a Context (via @ApplicationContext, built into
  Hilt itself), no separate @Module is needed for this repository at
  all — the same "you own this class, just annotate the constructor"
  rule from Chapter 5 applies here.
- notificationsEnabled and setNotificationsEnabled wrap the raw
  DataStore calls from Challenge 1, exposing a clean, repository-level
  API — callers (a ViewModel, in Challenge 3) never touch
  PreferencesKeys or context.dataStore directly.