Move cards to other boards - Handling of tags & assignees

This is a discussion about the new feature "Move cards to other boards".

On the UI the tags and assignees of the old board are shown, therefore i guess you don't handle them.

This can (probably will) lead to strange errors when synchronizing - tags do exist, don't exist assigned users might exist or not - or have no permissions at this board. The web interface for example does not allow editing tags which are brought from other boards, in the board details such tags aren't displayed, one cannot filter for them etc.

I think you need a better handling here. Something like:

Tags

• If a tag with the same text exists, assign this tag instead of the other
• If no similar tag exists:
  • If user has permission to create tags, create a tag with this color and text and assign it
  • Else remove this tag from the card

Assignees

• If the user which is assigned to the card has at least view permission at the board, keep it
• Else de-assign the user from the card.

@desperateCoder this might really break a lot of stuff when syncing, be prepared 😄 We also will have to implement this behavior for https://github.com/stefan-niedermann/nextcloud-deck/issues/453 on our side, so i would appreciate a common solution here.

The issue names no implementation files, tests, or entry points. First locate the move-card synchronization path and its tag and assignee handling; done means moved cards use valid board tags and retain only permitted assignees without synchronization errors.