Implemented progress bar integration with `ProgressBarContract` for real-time conversion tracking and status updates. Added queue management functionality to process files sequentially with error and completion handling. Extended `ConvertorContract` and `FFmpegContract` to support tracking of running processes and conversion progress.
Introduce encoder modules for various codecs and formats (e.g., h264_nvenc, libx264, libmp3lame). Add `Convertor` logic to retrieve supported formats via FFmpeg utilities and manage encoders for audio, video, and image processing.
Introduce a new layout system for managing main window content and tabs. Integrate file selection and drag-and-drop functionality for adding files to the conversion list, with automatic tab switching to "Added Files". Refactor existing components to support these features.
