Visibility: Separate "Busy" and "Private" Visibility Behaviors for Calendar Events

Currently, setting a calendar event's visibility to “Busy” in Akiflow also marks the event as “Private”, which may not align with user expectations.

The “Busy” setting is typically used to block off time on a calendar without necessarily hiding event details, while “Private” is meant to conceal those details from others. Since both affect visibility in different ways, it would be helpful if Akiflow allowed users to choose one without automatically applying the other.