Add navigation service for centralized login redirect routing

- Simplify token validation logic in API
- Update axios interceptor to use navigation service

lightrag_webui/src/features/DocumentManager.tsx

@@ -45,7 +45,6 @@ export default function DocumentManager() {
         } else {
           setDocs(null)
         }
-        // console.log(docs)
       } else {
         setDocs(null)
       }