groupAgendaDays keyed each instance by its start day alone, so a
multi-day event surfaced only on its first day and vanished from the
rest of its span in both the Agenda screen and the agenda widget.
Expand each instance across every day from its start (clamped to the
anchor for ongoing events) through its last occupied day, bounded by the
visible window end. An event ending exactly at midnight — including the
exclusive next-midnight all-day events end at — does not reach that
boundary day.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Jean-Luc Makiola
7ed1d89b66