- Remove the 7-day outlook strip and daily_outlook_at/3. It was
derived from point_forecast, which is capped at HRRR's 18-hour
horizon, so it never had 7 days of data to show.
- factors_for: fall back to the nearest persisted analysis profile
at or before the requested time. Only f00 hours persist profiles,
so clicking any other hour used to yield an empty Analysis and
factor table. After the recent cursor fix lands 'Now' on a
forecast hour more often, this regressed further.
- available_valid_times/1: cap the forward horizon to 18h from now.
Leftover valid_times from prior cycles used to pile on the
timeline without adding information.