feat(localization): expand language support and enhance UI for user settings

- Added support for additional UI locales including Cebuano and Spanish, improving accessibility for a broader user base.
- Updated language selection components in the AppHeader and SettingsWidget to reflect new language options, enhancing user experience.
- Enhanced localization of various UI elements across components, ensuring consistent language representation and improved user engagement.
- Implemented logic to synchronize user language preferences with backend settings, providing a seamless experience when changing languages.

backend/services/authService.js

@@ -4,6 +4,7 @@ import { v4 as uuidv4 } from 'uuid';
 import User from '../models/community/user.js';
 import UserParam from '../models/community/user_param.js';
 import UserParamType from '../models/type/user_param.js';
+import UserParamValue from '../models/type/user_param_value.js';
 import { sendAccountActivationEmail, sendPasswordResetEmail } from './emailService.js';
 import { sequelize } from '../utils/sequelize.js';
 import { Op } from 'sequelize';
@@ -143,6 +144,16 @@ export const loginUser = async ({ username, password }) => {
     const mappedParams = params.map(param => {
         return { 'name': param.paramType.description, 'value': param.value };
     });
+    const uiLocaleCodes = ['de', 'en', 'ceb', 'es'];
+    const langEntry = mappedParams.find((p) => p.name === 'language');
+    if (langEntry?.value && !uiLocaleCodes.includes(langEntry.value)) {
+        const idNum = parseInt(langEntry.value, 10);
+        const lookupId = Number.isNaN(idNum) ? langEntry.value : idNum;
+        const upv = await UserParamValue.findOne({ where: { id: lookupId } });
+        if (upv?.value && uiLocaleCodes.includes(upv.value)) {
+            langEntry.value = upv.value;
+        }
+    }
     console.log('return user');
     return {
         id: user.hashedId,