feat: add Go backend compatibility service scaffold

go-backend/internal/http/middleware/cors.go

@@ -0,0 +1,17 @@
+package middleware
+
+import "net/http"
+
+func CORS(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Origin", "*")
+		w.Header().Set("Access-Control-Allow-Headers", "*")
+		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT, OPTIONS")
+		w.Header().Set("Access-Control-Expose-Headers", "Authorization")
+		if r.Method == http.MethodOptions {
+			w.WriteHeader(http.StatusNoContent)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}