The local-airtime change re-sorted calendar events in Go using air_at,
the absolute UTC instant, which is nil whenever air_timezone is unset.
Since air_timezone is only inferred for a few networks/countries, most
events fell through to the alphabetical title tiebreak while still
displaying their raw air_time, so each day appeared scrambled.
Sort each local day by the wall-clock time the viewer actually sees,
mirroring the client: zoned events convert air_at into the viewer
timezone, unzoned events use the raw air_time, and date-only entries
(no air_time) sort last. The timezone reasoning lives in the new
catalog.CalendarEventLocalTime helper.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
