mir-backend-rust-actix

Make It Right (Actix-web module). Actix-web 4.x + async Rust specific reliability augmentation. Use alongside mir-backend and mir-backend-rust when the target stack is Actix-web — it carries the mechanical footguns that the framework-agnostic tiers deliberately omit: the multi-worker app data trap (state constructed inside the App factory closure yields N independent copies, not one shared instance), web::Data<T>…