Connect product/blog pages, mega menu, and instant search to Meshkee backend

Add /products (list + detail) and /blog (list + detail) routes backed by
the real Meshkee API, a real category-hierarchy mega menu (level 2/3 only),
debounced instant search proxied through a same-origin API route, and
tel:-link fallbacks on product cards when no price is set. Also fixes
Product price normalization to read the real API shape instead of a
guessed one, and hardens product linking against catalog sources that
don't expose a slug.

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

src/components/ui/Placeholder.tsx

@@ -5,6 +5,7 @@ type PlaceholderProps = {
   height?: string;
   label?: string;
   className?: string;
+  fit?: "cover" | "contain";
 };
 
 export function Placeholder({
@@ -14,6 +15,7 @@ export function Placeholder({
   height,
   label,
   className = "",
+  fit = "cover",
 }: PlaceholderProps) {
   return (
     <div
@@ -23,7 +25,7 @@ export function Placeholder({
       <img
         src={src}
         alt={alt}
-        className="absolute inset-0 h-full w-full object-cover"
+        className={`absolute inset-0 h-full w-full ${fit === "contain" ? "object-contain" : "object-cover"}`}
       />
       {label && (
         <span className="font-display pointer-events-none relative z-10 rounded bg-white/70 px-1.5 py-0.5 text-xs tracking-wider text-red-dark/50 uppercase">