fix: dbDelta separate tables, add SEOHead for page titles

1. License table creation:
   - dbDelta requires separate calls per CREATE TABLE
   - Split into sql_licenses and sql_activations
   - Added 'PRIMARY KEY  (id)' with two spaces (dbDelta requirement)

2. Page titles:
   - Added SEOHead to Cart page (title: Shopping Cart)
   - Added SEOHead to Checkout page (title: Checkout)
   - Shop already had SEOHead

3. usePageTitle hook created (alternative to SEOHead for non-Helmet usage)

customer-spa/src/pages/Checkout/index.tsx

@@ -4,6 +4,7 @@ import { useCartStore } from '@/lib/cart/store';
 import { useCheckoutSettings } from '@/hooks/useAppearanceSettings';
 import { Button } from '@/components/ui/button';
 import Container from '@/components/Layout/Container';
+import SEOHead from '@/components/SEOHead';
 import { formatPrice } from '@/lib/currency';
 import { ArrowLeft, ShoppingBag, MapPin, Check, Edit2, Loader2, X, Tag } from 'lucide-react';
 import { toast } from 'sonner';
@@ -339,6 +340,7 @@ export default function Checkout() {
 
   return (
     <Container>
+      <SEOHead title="Checkout" description="Complete your purchase" />
       <div className="py-8">
         {/* Header */}
         <div className="mb-8">