feat: comprehensive SEO system with keywords and schema markup

- Add 4-locale keyword configurations (SR, EN, DE, FR)
- Create schema generators (Product, Organization, Breadcrumb)
- Add React components for JSON-LD rendering
- Implement caching for keyword performance
- Abstract all SEO logic for maintainability

src/components/seo/JsonLd.tsx

@@ -0,0 +1,39 @@
+import Script from 'next/script';
+import { SchemaType } from '@/lib/seo/schema/types';
+
+interface JsonLdProps {
+  data: SchemaType | SchemaType[];
+}
+
+/**
+ * React component to render JSON-LD schema markup
+ * Uses Next.js Script component for proper loading
+ * 
+ * @param data - Single schema object or array of schemas
+ * @returns Script component with JSON-LD
+ * @example
+ * <JsonLd data={productSchema} />
+ * <JsonLd data={[productSchema, breadcrumbSchema]} />
+ */
+export function JsonLd({ data }: JsonLdProps) {
+  // Handle single schema or array
+  const schemas = Array.isArray(data) ? data : [data];
+  
+  return (
+    <>
+      {schemas.map((schema, index) => (
+        <Script
+          key={index}
+          id={`json-ld-${index}`}
+          type="application/ld+json"
+          strategy="afterInteractive"
+          dangerouslySetInnerHTML={{
+            __html: JSON.stringify(schema),
+          }}
+        />
+      ))}
+    </>
+  );
+}
+
+export default JsonLd;