refactor: eliminate hardcoded locale comparisons for antifragility

Created centralized helpers:
- src/lib/i18n/pageMetadata.ts: All page metadata (titles, descriptions, alt text)
- src/lib/i18n/productText.ts: Product-specific translated text (shortDescription, benefits)
- src/lib/i18n/metadata.ts: Helper functions for locale handling

Updated all pages to use centralized metadata:
- Homepage: Uses getPageMetadata for title, description, productionAlt
- Products page: Uses getPageMetadata
- Product detail: Uses getPageMetadata + getTranslatedShortDescription/getTranslatedBenefits
- About page: Uses getPageMetadata

ProductDetail component now uses:
- getTranslatedShortDescription() instead of locale comparison
- getTranslatedBenefits() instead of locale comparison

All user-facing text now goes through translation files or centralized helpers.
Adding a new language now requires only:
1. Add to SUPPORTED_LOCALES in locales.ts
2. Add LOCALE_CONFIG entry
3. Add entries to pageMetadata.ts and productText.ts
4. Add translation keys to message files

src/app/[locale]/products/[slug]/page.tsx

@@ -5,6 +5,8 @@ import Footer from "@/components/layout/Footer";
 import ProductDetail from "@/components/product/ProductDetail";
 import type { Product } from "@/types/saleor";
 import { routing } from "@/i18n/routing";
+import { getPageMetadata } from "@/lib/i18n/pageMetadata";
+import { isValidLocale, DEFAULT_LOCALE, getSaleorLocale, type Locale } from "@/lib/i18n/locales";
 
 interface ProductPageProps {
   params: Promise<{ locale: string; slug: string }>;
@@ -16,8 +18,8 @@ export async function generateStaticParams() {
   
   for (const locale of locales) {
     try {
-      const productLocale = locale === "sr" ? "SR" : "EN";
-      const products = await getProducts(productLocale, 100);
+      const saleorLocale = locale === "sr" ? "SR" : "EN";
+      const products = await getProducts(saleorLocale, 100);
       products.forEach((product: Product) => {
         params.push({ locale, slug: product.slug });
       });
@@ -29,16 +31,18 @@ export async function generateStaticParams() {
 
 export async function generateMetadata({ params }: ProductPageProps) {
   const { locale, slug } = await params;
-  const productLocale = locale === "sr" ? "SR" : "EN";
-  const product = await getProductBySlug(slug, productLocale);
+  const validLocale = isValidLocale(locale) ? locale : DEFAULT_LOCALE;
+  const metadata = getPageMetadata(validLocale as Locale);
+  const saleorLocale = validLocale === "sr" ? "SR" : "EN";
+  const product = await getProductBySlug(slug, saleorLocale);
 
   if (!product) {
     return {
-      title: locale === "sr" ? "Proizvod nije pronađen" : "Product not found",
+      title: metadata.productNotFound,
     };
   }
 
-  const localized = getLocalizedProduct(product, productLocale);
+  const localized = getLocalizedProduct(product, saleorLocale);
 
   return {
     title: localized.name,
@@ -48,12 +52,13 @@ export async function generateMetadata({ params }: ProductPageProps) {
 
 export default async function ProductPage({ params }: ProductPageProps) {
   const { locale, slug } = await params;
-  setRequestLocale(locale);
+  const validLocale = isValidLocale(locale) ? locale : DEFAULT_LOCALE;
+  setRequestLocale(validLocale);
   const t = await getTranslations("Product");
-  const productLocale = locale === "sr" ? "SR" : "EN";
-  const product = await getProductBySlug(slug, productLocale);
+  const saleorLocale = getSaleorLocale(validLocale as Locale);
+  const product = await getProductBySlug(slug, saleorLocale);
 
-  const basePath = locale === "sr" ? "" : `/${locale}`;
+  const basePath = `/${validLocale}`;
 
   if (!product) {
     return (

src/app/[locale]/products/page.tsx

@@ -4,6 +4,8 @@ import Header from "@/components/layout/Header";
 import Footer from "@/components/layout/Footer";
 import ProductCard from "@/components/product/ProductCard";
 import { ChevronDown } from "lucide-react";
+import { getPageMetadata } from "@/lib/i18n/pageMetadata";
+import { isValidLocale, DEFAULT_LOCALE, getSaleorLocale, type Locale } from "@/lib/i18n/locales";
 
 interface ProductsPageProps {
   params: Promise<{ locale: string }>;
@@ -11,22 +13,21 @@ interface ProductsPageProps {
 
 export async function generateMetadata({ params }: ProductsPageProps) {
   const { locale } = await params;
+  const validLocale = isValidLocale(locale) ? locale : DEFAULT_LOCALE;
+  const metadata = getPageMetadata(validLocale as Locale);
   return {
-    title: locale === "sr" 
-      ? "Proizvodi - ManoonOils"
-      : "Products - ManoonOils",
-    description: locale === "sr"
-      ? "Pregledajte našu kolekciju premium prirodnih ulja za negu kose i kože."
-      : "Browse our collection of premium natural oils for hair and skin care.",
+    title: metadata.products.title,
+    description: metadata.products.description,
   };
 }
 
 export default async function ProductsPage({ params }: ProductsPageProps) {
   const { locale } = await params;
-  setRequestLocale(locale);
+  const validLocale = isValidLocale(locale) ? locale : DEFAULT_LOCALE;
+  setRequestLocale(validLocale);
   const t = await getTranslations("Products");
-  const productLocale = locale === "sr" ? "SR" : "EN";
-  const products = await getProducts(productLocale);
+  const saleorLocale = getSaleorLocale(validLocale as Locale);
+  const products = await getProducts(saleorLocale);
 
   return (
     <>