Initial commit of Descrybe v2 without local scratch artifacts.

Drop one-shot tmp/axe scripts and agent i18n scratch so the Gitea tree is deployable.

apps/api/internal/httpapi/locale_middleware.go

@@ -0,0 +1,64 @@
+package httpapi
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/descrybe/descrybe-v2/apps/api/internal/i18n"
+)
+
+// localeResponseWriter carries the resolved UI/API locale for Error()/CodedError.
+type localeResponseWriter struct {
+	http.ResponseWriter
+	locale string
+}
+
+func (w *localeResponseWriter) Locale() string { return w.locale }
+
+func (w *localeResponseWriter) Unwrap() http.ResponseWriter { return w.ResponseWriter }
+
+type localeCarrier interface {
+	Locale() string
+}
+
+type responseUnwrapper interface {
+	Unwrap() http.ResponseWriter
+}
+
+func localeOf(w http.ResponseWriter) string {
+	for w != nil {
+		if lc, ok := w.(localeCarrier); ok {
+			return lc.Locale()
+		}
+		uw, ok := w.(responseUnwrapper)
+		if !ok {
+			break
+		}
+		w = uw.Unwrap()
+	}
+	return i18n.Default
+}
+
+// Locale resolves Accept-Language into a supported UI locale, stores it on the
+// request context and ResponseWriter, and sets Vary: Accept-Language.
+func Locale(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		lang := i18n.Resolve(r.Header.Get("Accept-Language"))
+		ctx := i18n.WithLocale(r.Context(), lang)
+		if v := w.Header().Get("Vary"); v == "" {
+			w.Header().Set("Vary", "Accept-Language")
+		} else if !containsCSVToken(v, "Accept-Language") {
+			w.Header().Set("Vary", v+", Accept-Language")
+		}
+		next.ServeHTTP(&localeResponseWriter{ResponseWriter: w, locale: lang}, r.WithContext(ctx))
+	})
+}
+
+func containsCSVToken(header, token string) bool {
+	for _, part := range strings.Split(header, ",") {
+		if strings.TrimSpace(part) == token {
+			return true
+		}
+	}
+	return false
+}