FIX: Clear notification of skipped narrative bot PM (PR #10792)

Resets a new user’s PM count in their badge after skipping user tips.


Since we’re deleting the post, should we delete the notification instead?

Surprised rubocop didn’t pick that one

    if notification.present?

The notification is deleted by the PostDestroyer below. I added another check to the spec to reflect that.

We do need to mark it as read before it’s deleted and refresh the user’s notifications state so that the badge gets cleared.

LGTM :+1: