Merge dev into master: resolve middleware conflict (use dev version with full locale detection)

Redirect old Serbian URLs (without /sr/ prefix) to new /sr/ URLs:
- / → /sr (301)
- /products → /sr/products (301)
- /about → /sr/about (301)
- /contact → /sr/contact (301)
- /checkout → /sr/checkout (301)

English URLs (/en/*) remain unchanged. This preserves SEO value
as Google treats 301 as permanent redirect passing ~90-99% PageRank.

middleware.ts

@@ -48,4 +48,4 @@ export const config = {
     "/(sr|en|de|fr)/:path*",
     "/((?!api|_next|_vercel|.*\\..*).*)",
   ],
-};
+};

src/app/[locale]/page.tsx

@@ -206,7 +206,7 @@ export default async function Homepage({ params }: { params: Promise<{ locale: s
                   <input
                     type="email"
                     placeholder={t("emailPlaceholder")}
-                    className="flex-1 min-w-0 px-5 !h-14 bg-white/10 border border-white/20 border-b-0 sm:border-b border-r-0 sm:border-r border-white/20 text-white placeholder:text-white/50 focus:border-white focus:outline-none transition-colors text-base text-center sm:text-left rounded-t sm:rounded-l sm:rounded-tr-none"
+                    className="flex-1 min-w-0 px-5 !h-16 bg-white/10 border border-white/20 border-b-0 sm:border-b border-r-0 sm:border-r border-white/20 text-white placeholder:text-white/50 focus:border-white focus:outline-none transition-colors text-base text-center sm:text-left rounded-t sm:rounded-l sm:rounded-tr-none"
                   />
                   <button
                       type="submit"

src/components/home/NewsletterSection.tsx

@@ -54,7 +54,7 @@ export default function NewsletterSection() {
               onChange={(e) => setEmail(e.target.value)}
               placeholder={t("emailPlaceholder")}
               required
-              className="flex-1 px-4 py-4 h-12 border border-[#1A1A1A]/10 rounded-[4px] text-sm focus:outline-none focus:border-[#1A1A1A]/30 transition-colors"
+              className="flex-1 px-4 py-4 h-14 border border-[#1A1A1A]/10 rounded-[4px] text-base focus:outline-none focus:border-[#1A1A1A]/30 transition-colors"
             />
             <button
               type="submit"