feat: add SEOHead to all SPA pages for dynamic page titles

Added SEOHead component to:
- ThankYou page (both template styles)
- Login page
- Account/Dashboard
- Account/Orders
- Account/Downloads
- Account/Addresses
- Account/Wishlist
- Account/Licenses
- Account/AccountDetails
- Public Wishlist page

Also created usePageTitle hook as alternative for non-Helmet usage.

customer-spa/src/pages/Account/Downloads.tsx

@@ -4,6 +4,7 @@ import { Button } from '@/components/ui/button';
 import { api } from '@/lib/api/client';
 import { toast } from 'sonner';
 import { formatPrice } from '@/lib/currency';
+import SEOHead from '@/components/SEOHead';
 
 interface DownloadItem {
   download_id: string;
@@ -97,6 +98,7 @@ export default function Downloads() {
 
   return (
     <div>
+      <SEOHead title="Downloads" description="Your purchased downloads" />
       <h1 className="text-2xl font-bold mb-6">Downloads</h1>
 
       <div className="space-y-4">