axum-knowledge-patch

# Axum Knowledge Patch Baseline: Axum through 0.7.x. Covered range: `0.8-guide` and `0.8.0`, plus the included `axum-core`, `axum-extra`, and `axum-macros` companion-crate batches. ## Reference index | Reference | Topics | | --- | --- | | [routing-and-serving.md](references/routing-and-serving.md) | Handler and service bounds, path arity, generic listeners, static and typed routing, trailing-slash redirects | | [extractors-and-request-bodies.md](references/extractors-and-request-bodies.md) | Native async extractors, optional extraction, validation errors, strict JSON, body limits, multipart, typed headers, Host and Scheme | | [websockets-and-streaming.md](references/websockets-and-streaming.md) | WebSocket payloads and closure, HTTP/2 routing, subprotocols, fused streams, SSE | | [responses-and-middleware.md](references/responses-and-middleware.md) | Response status parts, unknown-size bodies, redirects, body normalization, content disposition, tracing | | [dependency-and-release-compatibility.md](references/dependency-and-release-compatibility.md) | Rust version requirements, yanked releases, axum-extra feature flags, prost compatibility, axum-macros fix | ## Apply this patch 1. Check `Cargo.lock` and feature selections before changing code; companion-crate behavior differs by patch release and several APIs are unreleased. 2. Address breaking routing, extractor, serving, and WebSocket changes first. 3. Read the matching reference before changing multipart, typed routing...