feat: stabilization + recipe edit/create UI

frontend/src/components/layout/BottomNav.tsx

@@ -0,0 +1,33 @@
+import { NavLink } from 'react-router'
+import { Home, Search, PlusCircle, ShoppingCart, User } from 'lucide-react'
+
+const navItems = [
+  { to: '/', icon: Home, label: 'Home' },
+  { to: '/search', icon: Search, label: 'Suche' },
+  { to: '/new', icon: PlusCircle, label: 'Neu' },
+  { to: '/shopping', icon: ShoppingCart, label: 'Einkauf' },
+  { to: '/profile', icon: User, label: 'Profil' },
+]
+
+export function BottomNav() {
+  return (
+    <nav className="fixed bottom-0 left-0 right-0 bg-surface border-t border-sand z-50">
+      <div className="max-w-lg mx-auto flex justify-around items-center h-16">
+        {navItems.map(({ to, icon: Icon, label }) => (
+          <NavLink
+            key={to}
+            to={to}
+            className={({ isActive }) =>
+              `flex flex-col items-center gap-0.5 text-xs transition-colors ${
+                isActive ? 'text-primary' : 'text-warm-grey'
+              }`
+            }
+          >
+            <Icon size={22} />
+            <span>{label}</span>
+          </NavLink>
+        ))}
+      </div>
+    </nav>
+  )
+}