RFC proposal: Invokable interface

Hi all, I'd like to propose an Invokable interface, the Stringable equivalent for __invoke(). The idea has come up a few times over the years (most recently in the PR #15492 discussion, where Gina suggested this exact approach) but never had a concrete implementation. I've put one together: https://github.com/php/php-src/pull/21574 It follows the Stringable pattern: auto-implemented for any class defining __invoke(), explicitly implementable with enforcement, and covariant to callable in return type checks. I'm working on a formal RFC and would love feedback before posting it. I'd also like to request wiki karma to create the RFC page — my wiki username is *aldemeery*. Thanks, Osama Aldemeery