Add product image gallery, harden Klaro border reset, remove attribution link

ProductGallery.tsx (main image + thumbnail strip) wired into
TodoKartenHero.tsx, only replacing the static hero photo once a
product actually has extra gallery photos — no visual change
otherwise. Backend field: Products.gallery (see payload repo).

Klaro's hard black border was still showing after the previous
color-only pass — the targeted border:none rule wasn't enough, so
this blanket-resets border/outline on every .klaro descendant and
re-adds only the shadow this theme actually wants. Also disables the
"Realisiert mit Klaro!" attribution link (BSD-3-Clause has no
on-page-attribution requirement, Klaro's own disablePoweredBy flag
covers this cleanly).

Updates the frontend README with the gallery + Klaro fixes.

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

app/lib/klaroConfig.ts

@@ -15,6 +15,7 @@ export type KlaroConfig = {
   acceptAll: boolean;
   hideDeclineAll: boolean;
   noticeAsModal: boolean;
+  disablePoweredBy: boolean;
   translations: Record<string, Record<string, unknown>>;
   services: {
     name: string;
@@ -96,6 +97,11 @@ export function buildKlaroConfig(codes: TrackingCode[], onAccept: (code: Trackin
     acceptAll: true,
     hideDeclineAll: false,
     noticeAsModal: false,
+    // Removes the "Realisiert mit Klaro!" attribution link in the modal —
+    // BSD-3-Clause has no on-page-attribution requirement (only source/
+    // binary copyright-notice retention), this is just the maintainers'
+    // own polite ask via a dedicated config flag, not a license term.
+    disablePoweredBy: true,
     translations: {
       de: {
         consentModal: {