- Remove all CLI/TUI functionality and command line arguments
- Update README to reflect GUI-only nature
- Simplify main() function to launch GUI directly
- Remove unused imports and display_stats function
- Replace spinbox with dropdown for time periods (All time, Last month, Last year)
- Add backwards compatibility for both old and new database formats
- Detect database schema automatically and use appropriate queries
- Fix compatibility with newer transfers.db format (StateDescription vs State)