Polish header icon alignment and banner hover overlays.

Align cart with search/profile controls and show banner slot text only on hover.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/Header.tsx

@@ -52,7 +52,7 @@ export default async function Header() {
         <div className="flex items-center gap-5">
           <button
             aria-label="جستجو"
-            className="text-neutral-600 transition-colors hover:text-primary"
+            className="inline-flex h-9 w-9 items-center justify-center text-neutral-600 transition-colors hover:text-primary"
           >
             <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" className="h-5 w-5">
               <circle cx="11" cy="11" r="7" stroke="currentColor" strokeWidth="1.8" />