- Added `ActiveTab` enum to manage active tab state in `App`.
- Created `BatchItem` struct and integrated `batch_items` vector in `App`.
- Developed `BatchPanel` component for managing batch projects with inline forms.
- Implemented sequential processing in `App::start_batch_item()` with automatic advancement in `poll_background()`.
- Updated UI to display individual item states (`⏳ Aguardando | ⟳ Processando | ✓ Concluído | ⊸ Cancelado | ✗ Erro`).
- Blocked item addition/removal during processing.
- Enhanced session persistence to include batch projects in `SessionData`.
- Updated session save/load functions to handle new session structure.
- Added domain entities for audio, subtitle, and video tracks.
- Created a Project entity to manage media editing sessions.
- Implemented value objects for file paths, sync offsets, track IDs, and languages.
- Developed infrastructure for asynchronous FFmpeg process execution.
- Built a user interface for selecting video files, adding audio and subtitle tracks, and managing output settings.
- Integrated error handling and logging for media processing tasks.