feat: localization service and frontend integration

- Add localization-service microservice (locale resolution, translations)
- Add frontend API routes /api/locale and /api/translations/[locale]
- Add LocalizationProvider and localization context
- Integrate localization into layout, EmptyChat, MessageInput components
- Update MICROSERVICES.md architecture docs
- Add localization-service to workspaces

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/frontend/src/components/EmptyChatMessageInput.tsx

@@ -5,10 +5,12 @@ import Sources from './MessageInputActions/Sources';
 import Optimization from './MessageInputActions/Optimization';
 import Attach from './MessageInputActions/Attach';
 import { useChat } from '@/lib/hooks/useChat';
+import { useTranslation } from '@/lib/localization/context';
 import ModelSelector from './MessageInputActions/ChatModelSelector';
 
 const EmptyChatMessageInput = () => {
   const { sendMessage } = useChat();
+  const { t } = useTranslation();
 
   /* const [copilotEnabled, setCopilotEnabled] = useState(false); */
   const [message, setMessage] = useState('');
@@ -62,7 +64,7 @@ const EmptyChatMessageInput = () => {
           onChange={(e) => setMessage(e.target.value)}
           minRows={2}
           className="px-2 bg-transparent placeholder:text-[15px] placeholder:text-black/50 dark:placeholder:text-white/50 text-sm text-black dark:text-white resize-none focus:outline-none w-full max-h-24 lg:max-h-36 xl:max-h-48"
-          placeholder="Ask anything..."
+          placeholder={t('input.askAnything')}
         />
         <div className="flex flex-row items-center justify-between mt-4">
           <Optimization />