Allow bold formatting in the spotlight product's marketing text

Products.spotlightText switches from a plain textarea to a richText field
(Lexical, same default editor as every other richText field here) so
admins get a formatting toolbar. Rendered via a small dedicated inline
converter (bold + paragraphs only) rather than the full block-oriented
RichText.tsx, which is styled for article-length content (blog posts,
legal pages) and would add heading/paragraph spacing this teaser doesn't
want.

app/lib/payload.ts

@@ -203,7 +203,13 @@ export type Product = {
   spotlight: boolean;
   spotlightEyebrow: string | null;
   spotlightHeadline: string | null;
-  spotlightText: string | null;
+  // Lexical richText JSON (switched from plain textarea 2026-08-25 so
+  // admins can bold parts of the teaser) — rendered by
+  // ProductSpotlight.tsx's own minimal inline converter, not the full
+  // article-oriented RichText.tsx (that one adds block-level heading/
+  // paragraph spacing meant for blog posts/legal pages, wrong fit for a
+  // single teaser paragraph).
+  spotlightText: unknown | null;
   spotlightImage: string | null;
   // Per-product opt-in for a wishlist heart on the homepage spotlight —
   // independent of (in addition to) the global wishlistEnabled toggle,
@@ -262,7 +268,7 @@ type PayloadProduct = {
   spotlight: boolean;
   spotlightEyebrow: string | null;
   spotlightHeadline: string | null;
-  spotlightText: string | null;
+  spotlightText: unknown | null;
   spotlightImage: { url: string } | number | null;
   spotlightShowWishlist: boolean;
   trackInventory: boolean;