Warning that you are commenting on closed issue
Problem to solve
We recently made the "moved" state more visible, but people are still commenting on closed issues in various scenarios.
Target audience
Further details
Proposal
We should show a warning in/around the comment box to a user that they are commenting on a closed issue. They may still want to do it for some reason, but this would prevent accidental conversations in the wrong/undiscoverable place.
Permissions and Security
Documentation
What does success look like, and how can we measure that?
Links / references
cc @victorwu