feat(i18n): add French language support and enhance localization

- Introduced French as a supported language across the application, updating locale files and adding translations for various components.
- Enhanced language handling logic to accommodate French, ensuring proper detection and fallback mechanisms.
- Updated UI elements to include French language options, improving accessibility for French-speaking users.
- Refactored SEO handling to include French in hreflang links, enhancing search engine indexing for multilingual content.
- Added new scripts for managing French translations and ensuring consistency across language files.

frontend/src/store/index.js

@@ -5,6 +5,7 @@ import router from '../router';
 import apiClient from '../utils/axios.js';
 import { io } from 'socket.io-client';
 import { getDaemonSocketUrl, getSocketIoUrl } from '../utils/appConfig.js';
+import { SUPPORTED_UI_LOCALES } from '../i18n/supportedLocales.js';
 
 const AUTH_KEYS = ['isLoggedIn', 'user', 'userid'];
 
@@ -30,8 +31,6 @@ function clearAuthStorage() {
   });
 }
 
-const SUPPORTED_UI_LOCALES = ['de', 'en', 'ceb', 'es'];
-
 function persistAuthStorage(user, rememberMe) {
   const targetStorage = rememberMe ? localStorage : sessionStorage;
   clearAuthStorage();
@@ -78,7 +77,15 @@ const store = createStore({
       if (browserLanguage.startsWith('de')) {
         return 'de';
       }
-      
+
+      if (browserLanguage.startsWith('fr')) {
+        return 'fr';
+      }
+
+      if (browserLanguage.startsWith('es')) {
+        return 'es';
+      }
+
       const allLanguages = navigator.languages || [navigator.language];
       for (const lang of allLanguages) {
         if (lang.startsWith('ceb') || lang.startsWith('bis')) {
@@ -97,7 +104,19 @@ const store = createStore({
           }
         }
       }
-      
+
+      for (const lang of allLanguages) {
+        if (lang.startsWith('fr')) {
+          return 'fr';
+        }
+      }
+
+      for (const lang of allLanguages) {
+        if (lang.startsWith('es')) {
+          return 'es';
+        }
+      }
+
       return 'en';
     })(),
     menu: JSON.parse(localStorage.getItem('menu')) || [],
@@ -147,9 +166,13 @@ const store = createStore({
       }
 
       const germanSpeakingCountries = ['de', 'at', 'ch', 'li'];
-      
+
       if (browserLanguage.startsWith('de')) {
         state.language = 'de';
+      } else if (browserLanguage.startsWith('fr')) {
+        state.language = 'fr';
+      } else if (browserLanguage.startsWith('es')) {
+        state.language = 'es';
       } else {
         const allLanguages = navigator.languages || [navigator.language];
         let isGerman = false;
@@ -173,7 +196,23 @@ const store = createStore({
             }
           }
         }
-        state.language = isGerman ? 'de' : 'en';
+        if (isGerman) {
+          state.language = 'de';
+          return;
+        }
+        for (const lang of allLanguages) {
+          if (lang.startsWith('fr')) {
+            state.language = 'fr';
+            return;
+          }
+        }
+        for (const lang of allLanguages) {
+          if (lang.startsWith('es')) {
+            state.language = 'es';
+            return;
+          }
+        }
+        state.language = 'en';
       }
     },
     setLanguage(state, language) {