v0.54.0: m Fill the widget's dry lane with the next hours and the next rain

The dry lane showed only the nowcast sentence, a radar line and the sunset.
It now shows the next five hours (time, sky, temperature), then when rain is
next expected and the sunset.

/api/v1/glance adds:
- hours: the next five full hours, each with a night flag.
- next_rain: the first Open-Meteo hour from now+2h with at least 0.1 mm,
  using amounts only, never probability; omitted when none is forecast.
- night: whether it is dark now, so the widget's hero shows a moon.

Clear hours after dark show a moon and partly cloudy ones a plain cloud,
matching the glance page, which now shares the same night check. Servers
without hours keep the older radar and sunset rows.