ProviderStore
class ProviderStore(context: Context, val presets: List<ProviderProfile> = ProviderProfile.Presets)(source)
Saved provider profiles (SharedPreferences) with their API keys and OAuth tokens kept encrypted in SecretStore; exposes the list and the selected profile as flows. presets (built in, the first one selected by default) are merged in on load, so new presets appear after an app update.