Add mobile swipe gallery, shared ProductCard, dynamic Datenschutz address, GSC verification

- ProductGallery: touch swipe (left/right) now navigates slides on mobile,
  previously click-only.
- New shared ProductCard component used by ProductGrid/RelatedProducts/
  MerklisteGrid — product title is now the card's link (replaces the
  separate "Mehr erfahren" line), consistent aspect ratio across all
  three grids, more compact cards.
- Datenschutz: name/address/email now come from company-settings via a
  new VerantwortlicherBlock, same single-source pattern as Impressum's
  AnbieterAngaben — no more hand-typed address to keep in sync.
- layout.tsx: render googleSearchConsoleVerification via Next's native
  verification.google metadata field.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/datenschutz/page.tsx

@@ -7,8 +7,9 @@ import { Footer } from "../components/Footer";
 import { RichText, extractHeadings } from "../components/RichText";
 import { LiveRichText } from "../components/LiveRichText";
 import { SectionTOC, MobileSectionTOC } from "../components/SectionTOC";
-import { getLegalPage } from "../lib/payload";
+import { getLegalPage, getCompanySettings } from "../lib/payload";
 import { formatMonthYear } from "../lib/format";
+import { VerantwortlicherBlock, verantwortlicherHeadings } from "./components/VerantwortlicherBlock";
 
 export const metadata: Metadata = {
   title: "Datenschutzerklärung",
@@ -18,8 +19,11 @@ export const metadata: Metadata = {
 
 export default async function DatenschutzPage() {
   const { isEnabled: isPreview } = await draftMode();
-  const page = await getLegalPage("datenschutz", { draft: isPreview });
-  const headings = page ? extractHeadings(page.content) : [];
+  const [page, seller] = await Promise.all([getLegalPage("datenschutz", { draft: isPreview }), getCompanySettings()]);
+  // "1. Verantwortlicher" headings first — that block renders above the
+  // CMS content below (same reasoning as Impressum's own headings
+  // composition, see AnbieterAngaben.tsx).
+  const headings = [...verantwortlicherHeadings(), ...(page ? extractHeadings(page.content) : [])];
 
   return (
     <>
@@ -69,7 +73,11 @@ export default async function DatenschutzPage() {
             </div>
           </div>
 
-          <div className="w-full lg:flex-1 min-w-0">
+          <div className="w-full lg:flex-1 min-w-0 flex flex-col gap-8">
+            {/* Name/Adresse/E-Mail kommen direkt aus company-settings, nicht
+                aus der CMS-Richtext unten — single-sourced, gleiche
+                Begründung wie Impressum's AnbieterAngaben.tsx. */}
+            {seller && <VerantwortlicherBlock seller={seller} />}
             {page ? (
               isPreview ? <LiveRichText initialContent={page.content} /> : <RichText content={page.content} />
             ) : (