Add a sticky site footer

Adds a Footer with the brand, quick links (Menu, Basket, Your orders,
Help), and a copyright line, rendered on every page. Body is now a
full-height flex column so the footer sits at the bottom of the
viewport on short pages instead of floating right under the content.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/routes/__root.tsx

@@ -6,6 +6,7 @@ import {
 } from '@tanstack/react-router'
 
 import { BasketLink } from '#/components/basket/BasketLink.tsx'
+import { Footer } from '#/components/ui/Footer.tsx'
 import { Logo } from '#/components/ui/Logo.tsx'
 import { NotFound } from '#/components/ui/NotFound.tsx'
 import BetterAuthHeader from '#/integrations/better-auth/header-user.tsx'
@@ -40,7 +41,8 @@ const RootDocument = ({ children }: { children: React.ReactNode }) => {
               <BetterAuthHeader />
             </div>
           </div>
-          {children}
+          <div className={styles.content}>{children}</div>
+          <Footer brandName={brand.name} />
         </BasketProvider>
         <Scripts />
       </body>