Constant JSON 

pub const JSON: &[&str];

The extensions each half consumes, and their union.

EXPORTED so registry.rs can DECLARE the scope from the same constant the check FILTERS with. They drifted: the registry declared [".json", ".yaml", ".yml"] while this module asked for [".yaml"], so amont list reported the check as covering .yml and a staged, broken x.yml returned Outcome::Passed with no output at all. A const fn over a const is legal in a const item, so the registry can reference these directly and the two cannot disagree again.