feat: Add Russian i18n translations and fix CORS + API endpoint issues

- Implemented full Russian translation (ru) for 8 major pages
- Added LanguageSwitcher component with language detection
- Translated: Navigation, Settings, Workflows, Credentials, Banner, Examples
- Fixed API endpoint path: changed to use sans-api-v1 client for /v1/ endpoints
- Fixed CORS: added http://localhost:8081 to ALLOWED_ORIGINS
- Added locales infrastructure with i18next and react-i18next
- Created bilingual JSON files (en/ru) for 4 namespaces
- 220+ translation keys implemented
- Backend CORS configuration updated in .env
- Documentation: I18N implementation guides and installation docs

start-frontend.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+# Skyvern Frontend Starter Script
+# Port: 8501 (Streamlit)
+
+cd "$(dirname "$0")/skyvern-frontend"
+
+echo "🎨 Запуск Skyvern Frontend..."
+echo ""
+
+# Проверить что backend запущен
+if ! curl -s http://localhost:8000/health > /dev/null 2>&1; then
+    echo "⚠️  Backend не запущен на http://localhost:8000"
+    echo "Запустите сначала: ./start-backend.sh"
+    echo ""
+    read -p "Продолжить запуск frontend? (y/n) " -n 1 -r
+    echo
+    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
+        exit 1
+    fi
+fi
+
+echo "Запуск Vite dev server..."
+echo "📍 Frontend будет доступен на: http://localhost:5173"
+echo ""
+echo "Для остановки нажмите Ctrl+C"
+echo ""
+
+npm run dev