When an artId is being created, the _initializeArt() function is called as part of the process. In this function the receiver address is stored in the PhiArt struct. The issue is that this address is not validated to not be address(0).
Due to this, during merkle or signature claiming from factory, the call would revert. This is because the handleRewardsAndGetValueSent() function calls the depositRewards() function that expects the receiver address of the artist to be non-zero as seen here.
Add the zero address check during artId creation, i.e., in _initializePhiArt() function.
