Calendar inbox view for shared calendar change notifications

Is your feature request related to a problem? Please describe.

I use the "notifications for calendar event updates" app to get notified when events on shared calendars are created, updated, or deleted. It works, but the notifications land in the general Nextcloud notification bell alongside file shares, Talk messages, and everything else. They're easy to miss and once dismissed, they're gone.

Apple Calendar solves this with an inbox built into the calendar app itself. Changes to shared calendars appear in a dedicated view that persists until you acknowledge them. It's a feature that makes shared family calendars work very well.

Describe the solution you'd like

An inbox view within the Calendar app that collects shared calendar change notifications and presents them in a persistent, calendar-specific list. Each entry would show what changed, who changed it, and when. Entries stay until the user dismisses them.

Describe alternatives you've considered

I use the current notification system within Nextcloud. The missing piece is a frontend view in the Calendar app that consumes those notifications in a dedicated UI rather than dumping them into the global notification bell.

Additional context

This is my first ever feature request. I hope I'm doing this correctly.

No files or tests are named. Start by tracing how the existing Nextcloud notification system delivers shared-calendar event updates and how the Calendar frontend presents them. Done means a calendar-specific inbox lists changes with what changed, who changed it, and when, and keeps entries until dismissal.