consolidate english language to use gb (#5002)

# Description of Changes

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- Why the change was made
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Closes #(issue_number)
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## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

frontend/src/core/i18n.ts

@@ -5,9 +5,7 @@ import Backend from 'i18next-http-backend';
 
 // Define supported languages (based on your existing translations)
 export const supportedLanguages = {
-  'en': 'English',
-  'en-GB': 'English (UK)',
-  'en-US': 'English (US)',
+  'en-GB': 'English',
   'ar-AR': 'العربية',
   'az-AZ': 'Azərbaycan Dili',
   'bg-BG': 'Български',
@@ -72,8 +70,7 @@ i18n
 
     backend: {
       loadPath: (lngs: string[], namespaces: string[]) => {
-        // Map 'en' to 'en-GB' for loading translations
-        const lng = lngs[0] === 'en' ? 'en-GB' : lngs[0];
+        const lng = lngs[0];
         const basePath = import.meta.env.BASE_URL || '/';
         const cleanBasePath = basePath.endsWith('/') ? basePath.slice(0, -1) : basePath;
         return `${cleanBasePath}/locales/${lng}/${namespaces[0]}.json`;
@@ -83,7 +80,11 @@ i18n
     detection: {
       order: ['localStorage', 'navigator', 'htmlTag'],
       caches: ['localStorage'],
-      convertDetectedLanguage: (lng: string) => lng === 'en' ? 'en-GB' : lng,
+      convertDetectedLanguage: (lng: string) => {
+        // Map en and en-US to en-GB
+        if (lng === 'en' || lng === 'en-US') return 'en-GB';
+        return lng;
+      },
     },
 
     react: {

frontend/src/core/utils/languageMapping.ts

@@ -13,7 +13,7 @@ const languageDefinitions: LanguageDefinition[] = [
   {
     ocrCode: 'eng',
     displayName: 'English',
-    browserCodes: ['en', 'en-US', 'en-GB', 'en-AU', 'en-CA', 'en-IE', 'en-NZ', 'en-ZA']
+    browserCodes: ['en', 'en-GB', 'en-AU', 'en-CA', 'en-IE', 'en-NZ', 'en-ZA']
   },
   
   // Spanish