- Add timezone configuration to config.ini and config.ini.example
- Update hello_command.py to use configured timezone for time-appropriate greetings
- Add pytz dependency to requirements.txt
- Support standard timezone names (America/New_York, Europe/London, etc.)
- Fallback to system timezone if configured timezone is invalid or empty
- Update core.py create_default_config to include timezone setting
- Time-appropriate greetings now work correctly across different timezones