Problem/Motivation
Clients often get confused when our team has rabbit-holed (page not found action) certain content types. They will create a node of said content type and save, which takes them to the node view, which often looks unfinished/unstyled, since our team doesn't want to put effort into styling a page that nobody other than Admin (or people will permission to bypass rabbit-hole) would see. We then need to explain to them that "don't worry, nobody else will see this", and they get it, but it would be nice if we didn't have to have that discussion every project we use it on, and usually a few more times throughout the lifecycle of the project.
Steps to reproduce
Rabbit hole a content type using the Page not found action. Visit that full node as admin (guess this could be for any entity type though) - see the page.
Proposed resolution
I think what might work is when you enable rabbit-hole on the entity and select Page not found another textarea could show up in those settings that says "Page not found messaging", and that would give site builders the option to display a message that admin would see when they visit a rabbit-holed full node to remind them that nobody else will see this. That was our team's initial thought. We also thought that might not be the best place for the configuration, it might be better to have a configuration form per entity type like "Rabbit-hold node page not found messaging" and that would apply to all rabbit-holed nodes... same for taxonomy terms, users, media... etc.
Remaining tasks
Doing it.
User interface changes
Undecided: I think it would make most sense to have the "Page not found messaging" field show on individual entity type edit forms, where you select the action, but it could be a more generic setting that applies to all of a certain entity type.
API changes
None
Data model changes
Another line in config for each entity_type rabbit hole settings config