Import confirmation on target calendar

Is your feature request related to a problem? Please describe.
The behaviour of the autoselected calendar before importing is dangerous. It doesn't ask the user to confirm the choice again and has no intelligent suggestion. Also the search box might provoke a wrong target calendar. A a result a users bulk inserts items to calendar / todo , which he can't undo / remove easily.

Describe the solution you'd like
Don't preselect existing calendars for imports anymore. Let users actively select (and maybe confirm?) the desired calendar.
If you offer more intelligence (e.g. look for name strings of existing calendars within filename - useful to imports), let user confirm the import, so he doesn't doubleclick by mistake.

Describe alternatives you've considered

• Preselect new calendar? (But I don't know a merge 2 calendar feature within NC, so the result might be not useful as well ... but at least non-destructive)
• Ask to undo after a import?

No files or tests are named. Start by tracing the calendar import flow and its target-calendar selection and search behavior; define the confirmation and non-destructive default before implementation. Done means imports require an intentional target choice or confirmation and avoid accidental bulk insertion.