An event with several reminders posted a separate notification for each one. Each occurrence now has one notification, and every later reminder replaces the earlier one in place. - The notification tag and the snooze alarm are keyed on the occurrence. Snooze, dismiss and open actions stay per reminder, so tapping them on an outdated notification can't remove the newer one. - A different reminder alerts again; the same reminder posted twice stays silent. - If several reminders of one occurrence are due in the same scan (e.g. after the phone was off), only the latest is posted. - A newly due reminder cancels a pending snooze for its occurrence, and a snoozed reminder doesn't re-show over a newer one. - Notifications posted before this change still dismiss and snooze, and a newer reminder for the same event replaces them. - Reminder and occurrence keys share one hash in `ReminderPlan`. Closes #463 Co-authored-by: Jean-Luc Makiola <business@jeanlucmakiola.de> Reviewed-on: https://codeberg.org/jlmakiola/calendula/pulls/468