🚧(frontend) prevent authentication retry on 401 responses

Stop retry attempts when receiving 401 Unauthorized from /me endpoint since
this clearly indicates authentication status. The original purpose of the /me
call is simply to determine if user is authenticated, and a 401 provides
sufficient information.

Prevents unnecessary network requests caused by React Query's automatic retry
behavior when re-raising exceptions, which was hiding the 401 status. Improves
performance and reduces server load during authentication failures.

Author: lebaudantoine

src/frontend/apps/impress/src/features/auth/api/useAuthQuery.tsx

@@ -9,14 +9,24 @@ import { User } from './types';
  * This function is called during frontend initialization to check
  * the user's authentication status through a session cookie.
  *
+ * If the user is not logged in, the api returns a 401 error.
+ * Here our wrapper just returns false in that case, without triggering an error:
+ * this is done to prevent unnecessary query retries with react query
+ *
  * @async
  * @function getMe
  * @throws {Error} Throws an error if the API request fails.
  * @returns {Promise<User>} A promise that resolves to the user data.
  */
-export const getMe = async (): Promise<User> => {
+export const getMe = async (): Promise<User | boolean> => {
   const response = await fetchAPI(`users/me/`);
-  if (!response.ok) {
+
+  // we assume that a 401 means the user is not logged in
+  if (!response.ok && response.status == 401) {
+    return false
+  }
+
+  if (!response.ok && response.status != 401) {
     throw new APIError(
       `Couldn't fetch user data: ${response.statusText}`,
       await errorCauses(response),

src/frontend/apps/impress/src/features/auth/hooks/useAuth.tsx

@@ -33,7 +33,7 @@ export const useAuth = () => {
 
   return {
     user,
-    authenticated: !!user && authStates.isSuccess,
+    authenticated: authStates.isSuccess ? user !== false : undefined,
     pathAllowed,
     ...authStates,
   };

src/frontend/apps/impress/src/features/language/hooks/useLanguageSynchronizer.ts

@@ -2,14 +2,14 @@ import { useCallback, useMemo, useRef } from 'react';
 import { useTranslation } from 'react-i18next';
 
 import { useConfig } from '@/core';
-import { useAuthQuery } from '@/features/auth/api';
 import { useChangeUserLanguage } from '@/features/language/api/useChangeUserLanguage';
 import { getMatchingLocales } from '@/features/language/utils/locale';
 import { availableFrontendLanguages } from '@/i18n/initI18n';
+import { useAuth } from "@/features/auth";
 
 export const useLanguageSynchronizer = () => {
   const { data: conf, isSuccess: confInitialized } = useConfig();
-  const { data: user, isSuccess: userInitialized } = useAuthQuery();
+  const { user, authenticated: userInitialized } = useAuth();
   const { i18n } = useTranslation();
   const { mutateAsync: changeUserLanguage } = useChangeUserLanguage();
   const languageSynchronizing = useRef(false);