fix(storefront): align store actions with actual DB schema

Reviewer caught three runtime breakages that the prior commit would
have introduced (the legacy supabase shim masked them by returning
null):

1. **getStorefrontStopBySlug queried 'WHERE slug = $1' on stops, but
   stops has no slug column** — every storefront stop-detail page
   would have 500'd. The 'stops table has a slug' assumption is
   pre-existing throughout the codebase (PublicStop type, sitemap,
   StopCard prop), but the column has never existed. Fix: switch the
   route param to the stop's UUID (id). Rename folder [slug] → [id]
   for honesty. Update StopCard prop and the two stops-list links to
   pass stop.id instead of stop.slug. The RPC get_public_stops_for_brand
   already returns id, so this is what was actually being rendered.

2. **getStorefrontWholesaleSettings selected four non-existent
   columns** (invoice_business_address/phone/email/website) on
   wholesale_settings — only invoice_business_name is defined. The
   contact pages had hardcoded fallbacks, but the broken query was
   still throwing 500 on every render. Fix: only return
   invoice_business_name, and drop the dead optional-chain references
   in the contact pages (the values were always going to be the
   hardcoded fallback anyway).

3. **getAIPreferences/saveAIPreferences referenced a non-existent
   brand_ai_settings table** — no migration defines it, and no file
   in the codebase imports either function. Deleted the whole
   preferences.ts module (dead code that would have 500'd the moment
   anyone wired it up).

4. **getStorefrontProducts returned price as cents** (no division),
   so storefronts rendered '$$3500' for a $35 product. Fix: divide
   by 100 in SQL; type already declares price: number, callers
   already format as $${price}.

Verified by:
- npx tsc --noEmit: zero new errors (only pre-existing Stripe API
  version and preconnect mock issues)
- npx vitest run: 174/175 (same baseline; pre-existing getAdminUser
  mock failure unchanged)
- Live dev server: /tuxedo, /indian-river-direct, /tuxedo/stops/[id],
  /wholesale/portal all return 200; the new action no longer throws
  'column slug does not exist'.

src/components/storefront/StopCard.tsx

@@ -2,7 +2,7 @@ import Link from "next/link";
 import { formatDate } from "@/lib/format-date";
 
 type StopCardProps = {
-  slug: string;
+  id: string;
   city: string;
   state: string;
   date: string;
@@ -13,7 +13,7 @@ type StopCardProps = {
 };
 
 export default function StopCard({
-  slug, city, state, date, time, location,
+  id, city, state, date, time, location,
   brandSlug = "tuxedo", brandAccent = "green",
 }: StopCardProps) {
   const ctaBg =
@@ -25,7 +25,7 @@ export default function StopCard({
 
   return (
     <div className="group overflow-hidden rounded-3xl bg-white ring-1 ring-stone-200/60 transition-all duration-300 hover:-translate-y-1 hover:shadow-xl hover:shadow-black/8 hover:ring-stone-300">
-      <Link href={`/${brandSlug}/stops/${slug}`} className="block p-7">
+      <Link href={`/${brandSlug}/stops/${id}`} className="block p-7">
         {/* Location */}
         <div className="flex items-start gap-4 mb-5">
           <div className={`flex h-10 w-10 flex-shrink-0 items-center justify-center rounded-xl transition-colors ${brandAccent === "blue" ? "bg-blue-50 group-hover:bg-blue-100" : brandAccent === "green" ? "bg-emerald-50 group-hover:bg-emerald-100" : "bg-orange-50 group-hover:bg-orange-100"}`}>
@@ -56,7 +56,7 @@ export default function StopCard({
       {/* CTA */}
       <div className="px-7 pb-7 pt-1">
         <Link
-          href={`/${brandSlug}/stops/${slug}`}
+          href={`/${brandSlug}/stops/${id}`}
           className={`block w-full rounded-2xl ${ctaBg} text-white px-5 py-3.5 text-center font-bold text-sm uppercase tracking-wider transition-colors`}
         >
           Shop This Stop