- Add FormatInTimezone and FormatTimestamptzInTimezone helpers
in templates/utils.go for timezone-aware time display
- Add Timezone field to templates.User struct
- Pass user timezone from DB to template context in helpers.go
- Add timezone update handling in auth.go UpdateProfile with
validation via time.LoadLocation
- Add UpdateTimezoneSettings handler in system_settings.go for
admin system-wide default timezone using UpdateSystemSetting