mir-backend-rust-axum

Make It Right (Axum module). Axum + Tower + async Rust specific reliability augmentation. Use alongside mir-backend and mir-backend-rust when the target stack is Axum — it carries the mechanical footguns that the framework-agnostic tiers deliberately omit: extractor ordering (body-consuming extractors must be last), typed State<T> vs Extension<T> and the FromRef sub-state pattern, implementing IntoResponse for error types, and Tower middleware layer ordering (outermost wraps first). TRIGGER only when the Rust backend framework is Axum — building, reviewing, or debugging an Axum handler, router, extractor, or middleware. Always loads TOGETHER WITH mir-backend (the gates) and mir-backend-rust (Tokio runtime concerns: blocking, guard-across-await, cancellation safety, Arc/'static, backpressure, timeouts); this module only adds Axum/Tower library mechanics. SKIP for Actix-web, Warp, Poem, or any non-Axum Rust stack (those get their own mir-backend-rust-<framework> module), and for non-Rust runtimes.