Release v0.1.2

Changes

• refactor: restructure codebase to Clean Architecture
  • Separate concerns into domain, application, and infrastructure layers
  • Introduce dedicated modules for parser, sanitizer, and types
  • Add application services: history, queue management, and commands
  • Implement infrastructure layer with file management, persistence, and steam client
  • Refactor frontend with new DownloadTab and HistoryTab components
  • Remove legacy queue.rs and steamcmd.rs in favor of modular design