Bug fixes:
- Fixed timer memory leak that could occur when reopening
- Fixed potential crash with UTC timezone initialization
- Fixed duplicate timezone detection to correctly allow timezone abbreviations (PST, EST) while still filtering duplicate cities
Changes:
- Added 31 timezone abbreviations to search (PST, EST, GMT, JST, IST, UTC, and more)
- Added drag-to-reorder: long-press (0.5s) and drag to rearrange clocks with haptic feedback
- Changed default cities to include PST for discoverability of timezone abbreviations
- Improved duplicate detection when adding new entries