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/lib/i18n/metadata.ts

@@ -1,17 +1,37 @@
-import { DEFAULT_LOCALE, LOCALE_CONFIG, type Locale } from "./locales";
-
-export function getMetadataText(locale: Locale, texts: Partial<Record<Locale, string>>): string {
-  return texts[locale] || texts[DEFAULT_LOCALE] || "";
-}
+import { DEFAULT_LOCALE, LOCALE_CONFIG, SUPPORTED_LOCALES, type Locale } from "./locales";
 
 export function getSaleorLocale(locale: Locale): string {
   return LOCALE_CONFIG[locale].saleorLocale;
 }
 
-export function getLocaleDisplayName(locale: Locale): string {
+export function getLocaleLabel(locale: Locale): string {
   return LOCALE_CONFIG[locale].label;
 }
 
 export function isDefaultLocale(locale: string): boolean {
   return locale === DEFAULT_LOCALE;
 }
+
+export function getLocaleFromParams(params: { locale: string }): Locale {
+  const { locale } = params;
+  if (SUPPORTED_LOCALES.includes(locale as Locale)) {
+    return locale as Locale;
+  }
+  return DEFAULT_LOCALE;
+}
+
+export function getProductLocale(locale: Locale): string {
+  return getSaleorLocale(locale);
+}
+
+export function buildHreflangAlternates(baseUrl: string): Record<string, string> {
+  const alternates: Record<string, string> = {};
+  for (const loc of SUPPORTED_LOCALES) {
+    if (loc === DEFAULT_LOCALE) {
+      alternates[loc] = baseUrl;
+    } else {
+      alternates[loc] = `${baseUrl}/${loc}`;
+    }
+  }
+  return alternates;
+}

src/lib/i18n/pageMetadata.ts

@@ -0,0 +1,98 @@
+import type { Locale } from "./locales";
+
+const PAGE_METADATA: Record<Locale, {
+  home: { title: string; description: string; productionAlt: string };
+  products: { title: string; description: string };
+  productNotFound: string;
+  about: { title: string; description: string; productionAlt: string };
+  contact: { title: string; description: string };
+}> = {
+  sr: {
+    home: {
+      title: "ManoonOils - Premium prirodna ulja za negu kose i kože",
+      description: "Otkrijte našu premium kolekciju prirodnih ulja za negu kose i kože.",
+      productionAlt: "Proizvodnja prirodnih ulja",
+    },
+    products: {
+      title: "Proizvodi - ManoonOils",
+      description: "Pregledajte našu kolekciju premium prirodnih ulja za negu kose i kože.",
+    },
+    productNotFound: "Proizvod nije pronađen",
+    about: {
+      title: "O nama - ManoonOils",
+      description: "Saznajte više o ManoonOils - naša priča, misija i posvećenost prirodnoj lepoti.",
+      productionAlt: "Proizvodnja prirodnih ulja",
+    },
+    contact: {
+      title: "Kontakt - ManoonOils",
+      description: "Kontaktirajte nas za sva pitanja o proizvodima, narudžbinama ili saradnji.",
+    },
+  },
+  en: {
+    home: {
+      title: "ManoonOils - Premium Natural Oils for Hair & Skin",
+      description: "Discover our premium collection of natural oils for hair and skin care.",
+      productionAlt: "Natural oils production",
+    },
+    products: {
+      title: "Products - ManoonOils",
+      description: "Browse our collection of premium natural oils for hair and skin care.",
+    },
+    productNotFound: "Product not found",
+    about: {
+      title: "About - ManoonOils",
+      description: "Learn more about ManoonOils - our story, mission, and commitment to natural beauty.",
+      productionAlt: "Natural oils production",
+    },
+    contact: {
+      title: "Contact - ManoonOils",
+      description: "Contact us for any questions about products, orders, or collaborations.",
+    },
+  },
+  de: {
+    home: {
+      title: "ManoonOils - Premium natürliche Öle für Haar & Haut",
+      description: "Entdecken Sie unsere Premium-Kollektion natürlicher Öle für Haar- und Hautpflege.",
+      productionAlt: "Natürliche Ölproduktion",
+    },
+    products: {
+      title: "Produkte - ManoonOils",
+      description: "Durchsuchen Sie unsere Kollektion premium natürlicher Öle für Haar- und Hautpflege.",
+    },
+    productNotFound: "Produkt nicht gefunden",
+    about: {
+      title: "Über uns - ManoonOils",
+      description: "Erfahren Sie mehr über ManoonOils und unsere Mission, premium natürliche Produkte anzubieten.",
+      productionAlt: "Natürliche Ölproduktion",
+    },
+    contact: {
+      title: "Kontakt - ManoonOils",
+      description: "Kontaktieren Sie uns für Fragen zu Produkten, Bestellungen oder Zusammenarbeit.",
+    },
+  },
+  fr: {
+    home: {
+      title: "ManoonOils - Huiles Naturelles Premium pour Cheveux & Peau",
+      description: "Découvrez notre collection premium d'huiles naturelles pour les soins capillaires et cutanés.",
+      productionAlt: "Production d'huiles naturelles",
+    },
+    products: {
+      title: "Produits - ManoonOils",
+      description: "Parcourez notre collection d'huiles naturelles premium pour les soins capillaires et cutanés.",
+    },
+    productNotFound: "Produit non trouvé",
+    about: {
+      title: "À propos - ManoonOils",
+      description: "En savoir plus sur ManoonOils et notre mission de fournir des produits naturels premium.",
+      productionAlt: "Production d'huiles naturelles",
+    },
+    contact: {
+      title: "Contact - ManoonOils",
+      description: "Contactez-nous pour toute question sur les produits, commandes ou collaborations.",
+    },
+  },
+};
+
+export function getPageMetadata(locale: Locale) {
+  return PAGE_METADATA[locale] || PAGE_METADATA.en;
+}

src/lib/i18n/productText.ts

@@ -0,0 +1,57 @@
+import type { Locale } from "./locales";
+
+const PRODUCT_TEXT: Record<Locale, {
+  defaultShortDescription: string;
+  defaultBenefits: string[];
+}> = {
+  sr: {
+    defaultShortDescription: "Premium prirodno ulje za vašu rutinu lepote.",
+    defaultBenefits: ["Prirodno", "Organsko", "Bez okrutnosti"],
+  },
+  en: {
+    defaultShortDescription: "Premium natural oil for your beauty routine.",
+    defaultBenefits: ["Natural", "Organic", "Cruelty-free"],
+  },
+  de: {
+    defaultShortDescription: "Premium natürliches Öl für Ihre Schönheitsroutine.",
+    defaultBenefits: ["Natürlich", "Bio", "Tierversuchsfrei"],
+  },
+  fr: {
+    defaultShortDescription: "Huile naturelle premium pour votre routine beauté.",
+    defaultBenefits: ["Naturel", "Bio", "Sans cruauté"],
+  },
+};
+
+export function getProductDefaults(locale: Locale) {
+  return PRODUCT_TEXT[locale] || PRODUCT_TEXT.en;
+}
+
+export function getTranslatedBenefits(
+  metadataBenefits: string[] | undefined,
+  locale: Locale
+): string[] {
+  const defaults = PRODUCT_TEXT[locale] || PRODUCT_TEXT.en;
+  
+  if (!metadataBenefits || metadataBenefits.length === 0) {
+    return defaults.defaultBenefits;
+  }
+  
+  return metadataBenefits.map((benefit, index) => {
+    const trimmed = benefit.trim();
+    if (!trimmed) {
+      return defaults.defaultBenefits[index] || trimmed;
+    }
+    return trimmed;
+  });
+}
+
+export function getTranslatedShortDescription(
+  description: string | undefined,
+  locale: Locale
+): string {
+  if (description && description.trim()) {
+    return description.split('.')[0] + '.';
+  }
+  const defaults = PRODUCT_TEXT[locale] || PRODUCT_TEXT.en;
+  return defaults.defaultShortDescription;
+}