// Package mw provides transport-level HTTP middleware for Einherjar services.
//
// All middleware functions return func(http.Handler) http.Handler and are
// composed via [server.WithMiddleware] or chi's Use method.
//
// # Recommended middleware order (outermost first)
//
//	server.WithMiddleware(
//	    mw.Recover(logger),
//	    mw.RequestID(uuid.NewString),
//	    mw.RequestLogger(logger),
//	    mw.CORS([]string{"https://example.com"}),
//	)
//
// # Request IDs
//
// [RequestID] always generates a fresh ID. To continue a correlation ID a client
// already sent — so a distributed trace survives this boundary — use [RequestIDFrom]
// and read the ID off the request in your resolver. The framework does not read the
// header or validate the value: what is acceptable is per-service (a typed audit
// column rejects what an opaque log accepts), so that policy stays with the caller.
//
//	mw.RequestIDFrom(func(r *http.Request) string {
//	    if id, err := uuid.Parse(r.Header.Get("X-Request-ID")); err == nil {
//	        return id.String()   // continue the client's id
//	    }
//	    return uuid.NewString()  // otherwise mint one
//	})
//
// # Rate limiting
//
//	// In-memory (default — no extra dependencies)
//	store := mw.NewInMemoryRateLimiterStore(100, 20)
//	srv.Use(mw.IPRateLimit(store, logger))
//
//	// Distributed — swap store, middleware unchanged
//	store := valkeymw.NewRateLimiterStore(client, 100, 20)
//	srv.Use(mw.IPRateLimit(store, logger))
package mw