Administration setting to disable or hide "personal" calendar for all users by default

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

Some time ago I created #6015 because the persistence (being recreated after deletion) of the personal calendar was a problem for our environment where we only use a shared calendar. This prevented me from updating the Calendar App.

I have done a full update to latest versions (Nextcloud 31.0.8 and Calendar 5.3.8) on my test environment, and it looks like now when hiding the personal calendar for a user appointments are correctly created in the shared calendar.

The problem is that I would need to instruct all my users to hide their personal calendar in their profile to be sure that all them create the appointments in the shared calendar.

Describe the solution you'd like

As far as I have been searching around, it is not possible to disable the personal calendar in NextCloud.

It would be great to have a way in the Nextcloud administration that would allow the admins either to disable or hide the personal calendar by default for all users (existing and new ones in the future).

Describe alternatives you've considered

No response

Additional context

No response

Start by reviewing issue #6015 and the current profile setting that hides a user's personal calendar. Trace how that setting affects personal-calendar creation and how administration settings are stored and applied to existing and new users. Done means an administrator can disable or hide personal calendars by default without requiring each user to change the setting.