- Add guard checks in AppViewModel to prevent sync when hasFinishedSetup is false
- Share Extension now shows friendly UI when app not configured or session expired
- Check token existence via KeychainHelper instead of attempting API calls
- Improve 401 error messages: "Session expired. Please log in via the Readeck app."
- Replace #if DEBUG with BuildEnvironment.isDebugBuild for runtime checks
- Enable Debug Menu in both DEBUG and TestFlight builds
- Replace print() statements with Logger.sync/Logger.viewModel
- Add cache settings UseCases (get/update size, clear cache)
- Create CacheSettingsViewModel and OfflineSettingsViewModel
- Replace direct UserDefaults access with repository pattern
- Add CachedArticlesPreviewView for viewing offline articles
- Integrate offline settings into main SettingsContainerView
- Wire up new UseCases in factory pattern
