Updates outdated timezone identifiers in the database to their current
equivalents. This resolves ArgumentError exceptions when users have
outdated timezones like "Europe/Kiev" stored in their preferences.
Timezone mappings:
- Europe/Kiev → Europe/Kyiv
- Asia/Calcutta → Asia/Kolkata
- Asia/Katmandu → Asia/Kathmandu
- Asia/Rangoon → Asia/Yangon
- Asia/Saigon → Asia/Ho_Chi_Minh
- Pacific/Ponape → Pacific/Pohnpei
- Pacific/Truk → Pacific/Chuuk
🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>