Add offline merchant category suggestions

src/app/add-expense/page.tsx

@@ -12,7 +12,7 @@ export default function AddExpensePage() {
         <p className="text-sm font-semibold uppercase tracking-[0.28em] text-amber-700">Add Expense</p>
         <h1 className="text-4xl font-semibold text-stone-950">Capture spending while it still feels fresh.</h1>
         <p className="text-lg leading-8 text-stone-600">
-          This first slice focuses on fast local entry. Each saved expense appears immediately in your running history.
+          Enter the shop name and the app can auto-fill a category locally for known merchants, with offline AI help for unfamiliar ones.
         </p>
       </header>