Make homepage carousels fully dynamic, drop brand carousels, dynamic logo/favicon

- Replace the two hardcoded homepage carousels (SpecialSaleCarousel
  pinned to store-specials group 0 only, TopSellingCarousel reading
  from an unrelated plain product query) with StoreSpecialCarousels:
  loops over every group GET /store-specials returns, using each
  group's own title. A new carousel created in the admin panel (e.g.
  the "بهترین‌ها از نگاه شما" one just added) shows up automatically,
  no code change needed.
- Remove the brand-groups integration and its "سامسونگ" carousel
  entirely (getBrandGroups, BrandGroupCarousels) — brand-name
  carousels aren't wanted on this site per explicit instruction.
- SectionTitle's enTitle is now optional, since dynamic store-specials
  groups only have one title string, not a Persian/English pair.
- Move featured categories above the hero-adjacent special carousels
  per the requested homepage order; drop the "دسته‌بندی‌های پرطرفدار"
  heading and its "همه دسته‌ها" button, per request.
- Wire the header/footer logo and the favicon to the real business
  data (logoUrl/logoDarkUrl/faviconUrl from GET business-info) instead
  of static files; removed src/app/favicon.ico, which was silently
  winning over the new dynamic <link rel="icon">.
- CONTEXT.md: document the dynamic-carousel contract and the
  logo/favicon wiring so neither regresses to hardcoded.

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

src/components/ui/SectionTitle.tsx

@@ -1,6 +1,6 @@
 type SectionTitleProps = {
   title: string;
-  enTitle: string;
+  enTitle?: string;
   subtitle?: string;
   action?: string;
 };
@@ -11,13 +11,15 @@ export function SectionTitle({ title, enTitle, subtitle, action }: SectionTitleP
       <div>
         <div className="flex flex-wrap items-baseline gap-x-3 gap-y-1">
           <h2 className="text-xl font-bold text-red-dark md:text-2xl">{title}</h2>
-          <span
-            className="font-display text-sm font-semibold tracking-wide text-red-dark/30 uppercase md:text-base"
-            lang="en"
-            dir="ltr"
-          >
-            {enTitle}
-          </span>
+          {enTitle && (
+            <span
+              className="font-display text-sm font-semibold tracking-wide text-red-dark/30 uppercase md:text-base"
+              lang="en"
+              dir="ltr"
+            >
+              {enTitle}
+            </span>
+          )}
         </div>
         {subtitle && (
           <p className="mt-1 text-sm text-muted">{subtitle}</p>