- Add protocols for all UseCases and implement them in their respective classes
- Add DefaultUseCaseFactory and MockUseCaseFactory for dependency injection
- Implement all mock UseCases with dummy data
- Start migration of view models and views to protocol-based UseCase injection (not all migrated yet)
- Refactor previews and some initializers for easier testing
- Move SectionHeader to Components, update server settings UI text
- Add sample article.html for mock content
- Move and replace utility files (SafariUtil, SpeechQueue, StringExtensions, TTSManager, VoiceManager)
- Refactor and extend SpeechPlayer components (UI, progress, volume, queue)
- Improved state and EnvironmentObject management (PlayerUIState)
- UI and logic optimizations in menu and tab views
- Remove obsolete and duplicate files
- General code and UX improvements