fix language selection and missing locales

src/pages/Settings.jsx

@@ -23,6 +23,16 @@ export default function Settings() {
   });
   const [savingProfile, setSavingProfile] = useState(false);
   const [savingPassword, setSavingPassword] = useState(false);
+
+  const handleLanguageChange = async (lang) => {
+    setLanguage(lang);
+    try {
+      const res = await api.put('/auth/profile', { language: lang });
+      updateUser(res.data.user);
+    } catch {
+      // Language is still saved locally even if API fails
+    }
+  };
   const [activeSection, setActiveSection] = useState('profile');
   const [uploadingAvatar, setUploadingAvatar] = useState(false);
   const fileInputRef = useRef(null);
@@ -44,6 +54,7 @@ export default function Settings() {
         name: profile.name,
         email: profile.email,
         theme,
+        language,
         avatar_color: user?.avatar_color,
       });
       updateUser(res.data.user);
@@ -349,7 +360,7 @@ export default function Settings() {
                 ].map(lang => (
                   <button
                     key={lang.code}
-                    onClick={() => setLanguage(lang.code)}
+                    onClick={() => handleLanguageChange(lang.code)}
                     className={`flex items-center gap-3 p-4 rounded-xl border-2 transition-all ${
                       language === lang.code
                         ? 'border-th-accent shadow-md bg-th-accent/5'