- Plain tkinter GUI: file picker, listbox of selected videos
- Move Up / Move Down buttons to reorder the sequence
- Output name entry + output directory chooser
- Optional 'delete originals after concatenation' checkbox
- Concatenates with the ffmpeg concat demuxer (-c copy) on a worker thread
- Crude fixed time estimate (5s-per-file countdown before running ffmpeg)
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
