Follow Products.description consolidation to richText-only

Backend dropped the plain-text description field in favor of a single
richText one (see docker/payload commit 1ba8d07). Renders formatted
(bold/italic/multiple paragraphs) via the shared RichText component on
the PDP (der-eine, tasse-die-pause); everywhere else (Passend-dazu cards,
Product JSON-LD, homepage spotlight fallback) derives plain text at read
time via a new extractPlainText() helper instead of a second field.
Removes the description line from cart line items entirely — it only
bloated the cart with no real benefit there.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J1Hu5bZ1kZUgKhab6yNwCt

app/lib/payload.ts

@@ -181,7 +181,12 @@ export type Product = {
   // slug-based call site.
   numericId: number;
   name: string;
-  description: string;
+  // Raw Lexical richText JSON — rendered formatted (bold/italic/multiple
+  // paragraphs) on the PDP via the shared <RichText> component. Plain-text
+  // consumers (Passend-dazu cards, JSON-LD) use `descriptionText` below
+  // instead of re-deriving text from this themselves.
+  description: unknown | null;
+  descriptionText: string;
   // Not shown anywhere in the UI today — only consumed by
   // buildProductSchema (JSON-LD's Product.sku), a real Schema.org property
   // Google's rich-result validator looks for.
@@ -267,7 +272,7 @@ type PayloadProduct = {
   id: number;
   name: string;
   slug: string;
-  description: string | null;
+  description: unknown | null;
   sku: string | null;
   price: number;
   compareAtPrice: number | null;
@@ -325,16 +330,34 @@ function maxPurchasableQty(trackInventory: boolean, stock: number | null, allowB
   return trackInventory && !allowBackorder ? (stock ?? 0) : null;
 }
 
+type LexicalTextNode = {
+  text?: string;
+  children?: LexicalTextNode[];
+};
+
+// Mirrors the backend's own Posts.ts extractPlainText (same shape, same
+// space-joined fallback for multiple paragraphs/children) — kept as a
+// separate copy rather than a shared package since it's a few lines and
+// the two run in different runtimes (Payload server vs. this frontend).
+function extractPlainText(node: LexicalTextNode | null | undefined): string {
+  if (!node) return "";
+  if (typeof node.text === "string") return node.text;
+  if (Array.isArray(node.children)) return node.children.map(extractPlainText).join(" ");
+  return "";
+}
+
 // Shared by getProducts() and getPostBySlug()'s relatedProduct — kept in
 // one place instead of duplicating the same field mapping, which is
 // exactly the kind of drift this session's Shipping Settings work was
 // about eliminating elsewhere.
 export function mapPayloadProduct(product: PayloadProduct): Product {
+  const descriptionRoot = (product.description as { root?: LexicalTextNode } | null)?.root;
   return {
     id: product.slug,
     numericId: product.id,
     name: product.name,
-    description: product.description ?? "",
+    description: product.description ?? null,
+    descriptionText: extractPlainText(descriptionRoot),
     sku: product.sku || null,
     price: product.price,
     compareAtPrice: product.compareAtPrice ?? null,