Add independent agendaScreenRange and agendaWidgetRange preferences, each a rolling window: 1 day / 1 week / 1 month / custom 1–365 days (default Month). Rolling (not calendar-aligned) so the span never degenerates near a period boundary. The in-app Agenda screen and the agenda widget each read their own setting, configured via a new AgendaRangePicker with an inline custom-days editor. Closes #4 (Codeberg) Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>