mir-backend-rust-actix

Make It Right (Actix-web module). Actix-web + 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> Arc semantics and the .app_data vs .data deprecation, worker-local single-threaded actix-rt execution (!Send types allowed but blocking still starves the worker), extractor configuration via JsonConfig/QueryConfig, and error handling via the ResponseError trait. TRIGGER only when the Rust backend framework is Actix-web — building, reviewing, or debugging an Actix-web handler, middleware, extractor, or app factory. Always loads TOGETHER WITH mir-backend (the gates) and mir-backend-rust (Tokio runtime concerns: blocking, cancellation safety, Arc/'static, backpressure, timeouts); this module only adds Actix-web library mechanics. SKIP for Axum, Warp, Poem, or any non-Actix Rust stack (those get their own mir-backend-rust-<framework> module), and for non-Rust runtimes.