feat: add site assistant component for guided tool selection

- Introduced SiteAssistant component to assist users in selecting the right tools based on their queries.
- Integrated assistant into the main App component.
- Implemented message handling and storage for user-assistant interactions.
- Added quick prompts for common user queries related to tools.
- Enhanced ToolLandingPage and DownloadButton components with SharePanel for sharing tool results.
- Updated translations for new assistant features and sharing options.
- Added API methods for chat functionality with the assistant, including streaming responses.

frontend/src/App.tsx

@@ -3,6 +3,7 @@ import { Routes, Route, useLocation } from 'react-router-dom';
 import Header from '@/components/layout/Header';
 import Footer from '@/components/layout/Footer';
 import CookieConsent from '@/components/layout/CookieConsent';
+import SiteAssistant from '@/components/layout/SiteAssistant';
 import ErrorBoundary from '@/components/shared/ErrorBoundary';
 import ToolLandingPage from '@/components/seo/ToolLandingPage';
 import { useDirection } from '@/hooks/useDirection';
@@ -154,6 +155,7 @@ export default function App() {
       </main>
 
       <Footer />
+      <SiteAssistant />
       <CookieConsent />
     </div>
   );