Refactor navigation and authentication flow

- Move navigation setup to AppRouter
- Prevent protected route logic to handle login 401

lightrag_webui/src/features/LoginPage.tsx

@@ -48,7 +48,7 @@ const LoginPage = () => {
             toast.info(status.message)
           }
           navigate('/')
-          return; // Exit early, no need to set checkingAuth to false
+          return // Exit early, no need to set checkingAuth to false
         }
       } catch (error) {
         console.error('Failed to check auth configuration:', error)
@@ -95,11 +95,17 @@ const LoginPage = () => {
       } else {
         toast.success(t('login.successMessage'))
       }
-
+      
+      // Navigate to home page after successful login
       navigate('/')
     } catch (error) {
       console.error('Login failed...', error)
       toast.error(t('login.errorInvalidCredentials'))
+      
+      // Clear any existing auth state
+      useAuthStore.getState().logout()      
+      // Clear local storage
+      localStorage.removeItem('LIGHTRAG-API-TOKEN')
     } finally {
       setLoading(false)
     }