x

apps/website/src/app/[lang]/[slug]/page.tsx

@@ -1,5 +1,6 @@
 import { notFound } from 'next/navigation'
 import type { Metadata } from 'next'
+import { generateSeoMetadata } from '@/lib/seo'
 
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import { getCategoriesResult, getCmsPageResult } from '@/lib/cms'
@@ -38,9 +39,12 @@ export async function generateMetadata({ params }: { params: Promise<{ slug: str
   const pageResult = await getCmsPageResult(slug, lang)
   if (!pageResult.ok || !pageResult.data.isPublished) return { title: 'Page Not Found | HomAroma' }
 
-  return {
+  return generateSeoMetadata({
     title: `${pageResult.data.title} | HomAroma`,
-  }
+    description: `HomAroma - ${pageResult.data.title}`,
+    path: `/${slug}`,
+    lang,
+  })
 }
 
 export default async function CmsCustomPage({ params }: { params: Promise<{ slug: string, lang: string }> }) {

apps/website/src/app/[lang]/about/page.tsx

@@ -1,4 +1,5 @@
 import Link from '@/components/LocalizedLink'
+import { generateSeoMetadata } from '@/lib/seo'
 
 const PILLARS = [
   {
@@ -25,9 +26,14 @@ const STATS = [
   { value: '100%', label: 'Natural Extracts' },
 ]
 
-export const metadata = {
-  title: 'About Us | HomAroma',
-  description: 'Born from a passion for stillness. HomAroma began in 2019 as a Bangkok studio crafting botanical aroma blends.',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'About Us | HomAroma',
+    description: 'Born from a passion for stillness. HomAroma began in 2019 as a Bangkok studio crafting botanical aroma blends.',
+    path: '/about',
+    lang,
+  });
 }
 
 export default function AboutPage() {

apps/website/src/app/[lang]/article/[slug]/page.tsx

@@ -1,6 +1,7 @@
 import Link from '@/components/LocalizedLink'
 import { notFound } from 'next/navigation'
 import type { Metadata } from 'next'
+import { generateSeoMetadata } from '@/lib/seo'
 import { ArrowLeft } from 'lucide-react'
 import type { Article } from '@homaroma/types'
 
@@ -13,20 +14,22 @@ async function getArticle(slug: string): Promise<Article | null> {
   } catch { return null }
 }
 
-export async function generateMetadata({ params }: { params: Promise<{ slug: string }> }): Promise<Metadata> {
-  const { slug } = await params
+export async function generateMetadata({ params }: { params: Promise<{ slug: string, lang: string }> }): Promise<Metadata> {
+  const { slug, lang } = await params
   const article = await getArticle(slug)
   if (!article) return { title: 'Article Not Found | HomAroma' }
-  return {
+  return generateSeoMetadata({
     title: `${article.title} | HomAroma Scent Guide`,
     description: article.content.replace(/<[^>]+>/g, '').slice(0, 160),
+    path: `/article/${slug}`,
+    lang,
     openGraph: {
       title: article.title,
       images: article.coverImage ? [article.coverImage] : [],
       type: 'article',
       publishedTime: article.createdAt,
     },
-  }
+  })
 }
 
 export default async function ArticleReaderPage({ params }: { params: Promise<{ slug: string }> }) {

apps/website/src/app/[lang]/category/[id]/page.tsx

@@ -1,6 +1,7 @@
 import Link from '@/components/LocalizedLink'
 import { notFound } from 'next/navigation'
 import type { Metadata } from 'next'
+import { generateSeoMetadata } from '@/lib/seo'
 import type { Category, Product } from '@homaroma/types'
 import { getCategoryImage } from '@homaroma/types'
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
@@ -26,10 +27,12 @@ export async function generateMetadata({ params }: { params: Promise<{ id: strin
   const result = await getCategoryProducts(id, lang)
   const categoryName = result.ok && result.data.category ? resolveLocalized(result.data.category.name, lang) : ''
 
-  return {
+  return generateSeoMetadata({
     title: categoryName ? `${categoryName} | HomAroma` : 'Category | HomAroma',
     description: categoryName ? `Shop ${categoryName} products from HomAroma.` : 'Shop HomAroma category products.',
-  }
+    path: `/category/${id}`,
+    lang,
+  })
 }
 
 export default async function CategoryPage({ params }: { params: Promise<{ id: string, lang: string }> }) {

apps/website/src/app/[lang]/checkout/page.tsx

@@ -1,4 +1,5 @@
 import { CreditCard } from 'lucide-react'
+import { generateSeoMetadata } from '@/lib/seo'
 
 import CheckoutClient from '@/components/CheckoutClient'
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
@@ -6,9 +7,14 @@ import { getCategoriesResult, getCmsPageResult } from '@/lib/cms'
 import { splitCmsLayoutSections } from '@/lib/cms-sections'
 
 // lang is extracted from params
-export const metadata = {
-  title: 'Checkout | HomAroma',
-  description: 'ตรวจสอบรายการสินค้า กรอกข้อมูลจัดส่ง และสร้างคำสั่งซื้อ HomAroma',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'Checkout | HomAroma',
+    description: 'ตรวจสอบรายการสินค้า กรอกข้อมูลจัดส่ง และสร้างคำสั่งซื้อ HomAroma',
+    path: '/checkout',
+    lang,
+  });
 }
 
 export default async function CheckoutPage({ params }: { params: Promise<{ lang: string }> }) {

apps/website/src/app/[lang]/coupons/page.tsx

@@ -1,5 +1,6 @@
 import Link from '@/components/LocalizedLink'
 import { Ticket, ArrowRight } from 'lucide-react'
+import { generateSeoMetadata } from '@/lib/seo'
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import { getActiveCouponsResult, getCategoriesResult, getCmsPageResult } from '@/lib/cms'
 import { splitCmsLayoutSections } from '@/lib/cms-sections'
@@ -12,9 +13,14 @@ function formatDiscount(type: string, value: number) {
   return `${value}`
 }
 
-export const metadata = {
-  title: 'โปรโมชั่นและคูปองส่วนลด | HomAroma',
-  description: 'รวมรหัสส่วนลดและโปรโมชั่นพิเศษจาก HomAroma สำหรับการสั่งซื้อน้ำหอมและผลิตภัณฑ์อโรม่าที่คุณชื่นชอบ',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'โปรโมชั่นและคูปองส่วนลด | HomAroma',
+    description: 'รวมรหัสส่วนลดและโปรโมชั่นพิเศษจาก HomAroma สำหรับการสั่งซื้อน้ำหอมและผลิตภัณฑ์อโรม่าที่คุณชื่นชอบ',
+    path: '/coupons',
+    lang,
+  });
 }
 
 export default async function CouponsPage({ params }: { params: Promise<{ lang: string }> }) {

apps/website/src/app/[lang]/layout.tsx

@@ -1,4 +1,5 @@
 import type { Metadata } from 'next';
+import { notFound } from 'next/navigation';
 import '../globals.css';
 import Navbar from '@/components/Navbar';
 import Footer from '@/components/Footer';
@@ -6,6 +7,7 @@ import ClientProviders from '@/components/ClientProviders';
 import { API_BASE } from '@/lib/api';
 import type { MegaMenuPayload } from '@/components/navigation/menuTypes';
 import type { MenuItem, StoreSettings } from '@homaroma/types';
+import { isSupportedLocale } from '@/lib/locales';
 
 export const metadata: Metadata = {
   title: 'HomAroma',
@@ -82,6 +84,10 @@ export default async function RootLayout({
 }) {
   const { lang } = await params;
   
+  if (!isSupportedLocale(lang)) {
+    notFound();
+  }
+  
   const [categories, initialMenu, footerMenus, settings] = await Promise.all([
     getCategories(lang),
     getMegaMenu(lang),

apps/website/src/app/[lang]/order/[id]/page.tsx

@@ -1,6 +1,7 @@
 import Link from '@/components/LocalizedLink'
 import { notFound } from 'next/navigation'
 import type { Metadata } from 'next'
+import { generateSeoMetadata } from '@/lib/seo'
 import { CheckCircle2, Clock, PackageCheck, Truck } from 'lucide-react'
 import { formatPrice } from '@homaroma/types'
 
@@ -34,16 +35,18 @@ function statusTone(status: string) {
   return 'bg-gray-50 text-gray-700 border-gray-100'
 }
 
-export async function generateMetadata({ params }: { params: Promise<{ id: string }> }): Promise<Metadata> {
-  const { id } = await params
+export async function generateMetadata({ params }: { params: Promise<{ id: string, lang: string }> }): Promise<Metadata> {
+  const { id, lang } = await params
   const result = await getOrderResult(id)
 
   if (!result.ok) return { title: 'Order Not Found | HomAroma' }
 
-  return {
+  return generateSeoMetadata({
     title: `Order ${orderLabel(result.data.id)} | HomAroma`,
     description: `ตรวจสอบสถานะคำสั่งซื้อ ${orderLabel(result.data.id)} จาก HomAroma`,
-  }
+    path: `/order/${id}`,
+    lang,
+  })
 }
 
 export default async function OrderStatusPage({ params }: { params: Promise<{ id: string, lang: string }> }) {

apps/website/src/app/[lang]/page.tsx

@@ -1,4 +1,5 @@
 import type { Metadata } from 'next'
+import { generateSeoMetadata } from '@/lib/seo'
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import { getCategories, getCmsPage } from '@/lib/cms'
 import { splitCmsLayoutSections } from '@/lib/cms-sections'
@@ -11,10 +12,12 @@ export async function generateMetadata({ params }: Props): Promise<Metadata> {
   const { lang } = await params
   const page = await getCmsPage('home', lang)
 
-  return {
+  return generateSeoMetadata({
     title: page?.title ? `${page.title} | HomAroma` : 'HomAroma',
     description: 'Premium aromatherapy, home fragrance, and botanical scent products from HomAroma.',
-  }
+    path: '',
+    lang,
+  })
 }
 
 export default async function HomePage({ params }: Props) {

apps/website/src/app/[lang]/products/[id]/page.tsx

@@ -1,6 +1,7 @@
 import Link from '@/components/LocalizedLink'
 import { notFound } from 'next/navigation'
 import type { Metadata } from 'next'
+import { generateSeoMetadata } from '@/lib/seo'
 import { getCategoryImage, type Product } from '@homaroma/types'
 import AddToCartSection from '@/components/AddToCartSection'
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
@@ -25,15 +26,17 @@ export async function generateMetadata({ params }: { params: Promise<{ id: strin
   const categoryName = resolveCategoryName(product.category, lang)
   const description = resolveLocalized(product.description, lang)
 
-  return {
+  return generateSeoMetadata({
     title: `${productName} ${categoryName ? `| ${categoryName}` : ''} | HomAroma`,
     description: description || `Premium ${categoryName} from HomAroma.`,
+    path: `/products/${id}`,
+    lang,
     openGraph: {
       title: productName,
       description,
       images: product.images?.[0]?.url ? [product.images[0].url] : [],
     },
-  }
+  })
 }
 
 export default async function ProductDetailPage({ params }: { params: Promise<{ id: string, lang: string }> }) {

apps/website/src/app/[lang]/profile/page.tsx

@@ -1,4 +1,5 @@
 import { User } from 'lucide-react'
+import { generateSeoMetadata } from '@/lib/seo'
 
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import ProfileClient from '@/components/ProfileClient'
@@ -6,9 +7,14 @@ import { getCategoriesResult, getCmsPageResult } from '@/lib/cms'
 import { splitCmsLayoutSections } from '@/lib/cms-sections'
 
 // lang is extracted from params
-export const metadata = {
-  title: 'โปรไฟล์สมาชิก | HomAroma',
-  description: 'จัดการโปรไฟล์สมาชิก HomAroma ประวัติคำสั่งซื้อ คะแนนสะสม และสมุดที่อยู่จัดส่ง',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'โปรไฟล์สมาชิก | HomAroma',
+    description: 'จัดการโปรไฟล์สมาชิก HomAroma ประวัติคำสั่งซื้อ คะแนนสะสม และสมุดที่อยู่จัดส่ง',
+    path: '/profile',
+    lang,
+  });
 }
 
 export default async function ProfilePage({ params }: { params: Promise<{ lang: string }> }) {

apps/website/src/app/[lang]/scent-guide/page.tsx

@@ -1,12 +1,18 @@
 import Link from '@/components/LocalizedLink'
+import { generateSeoMetadata } from '@/lib/seo'
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import { getArticlesResult, getCategoriesResult, getCmsPageResult } from '@/lib/cms'
 import { splitCmsLayoutSections } from '@/lib/cms-sections'
 
 // lang is extracted from params
-export const metadata = {
-  title: 'Scent Guide | HomAroma',
-  description: 'Explore our collection of aroma articles, guides, and sensory knowledge to find your perfect scent.',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'Scent Guide | HomAroma',
+    description: 'Explore our collection of aroma articles, guides, and sensory knowledge to find your perfect scent.',
+    path: '/scent-guide',
+    lang,
+  });
 }
 
 export default async function ScentGuidePage({ params }: { params: Promise<{ lang: string }> }) {

apps/website/src/app/[lang]/search/page.tsx

@@ -1,13 +1,19 @@
 import Link from '@/components/LocalizedLink'
+import { generateSeoMetadata } from '@/lib/seo'
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import ProductCard from '@/components/ProductCard'
 import { getCategoriesResult, getCmsPageResult, getProductsResult } from '@/lib/cms'
 import { splitCmsLayoutSections } from '@/lib/cms-sections'
 import { resolveLocalized } from '@/lib/localization'
 
-export const metadata = {
-  title: 'Search Products | HomAroma',
-  description: 'Search HomAroma products by scent, category, or keyword.',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'Search Products | HomAroma',
+    description: 'Search HomAroma products by scent, category, or keyword.',
+    path: '/search',
+    lang,
+  });
 }
 
 export default async function SearchPage({ searchParams, params }: { searchParams: Promise<{ q?: string | string[] }>, params: Promise<{ lang: string }> }) {

apps/website/src/app/[lang]/shop/page.tsx

@@ -1,4 +1,5 @@
 import Link from '@/components/LocalizedLink'
+import { generateSeoMetadata } from '@/lib/seo'
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import ProductCard from '@/components/ProductCard'
 import ShopCouponBridge from '@/components/ShopCouponBridge'
@@ -7,9 +8,14 @@ import { splitCmsLayoutSections } from '@/lib/cms-sections'
 import { resolveLocalized } from '@/lib/localization'
 
 // lang is extracted from params
-export const metadata = {
-  title: 'Shop Aroma Products | HomAroma',
-  description: 'Browse HomAroma aroma oils, reed diffusers, room sprays, and premium scent products.',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'Shop Aroma Products | HomAroma',
+    description: 'Browse HomAroma aroma oils, reed diffusers, room sprays, and premium scent products.',
+    path: '/shop',
+    lang,
+  });
 }
 
 export default async function ShopPage({ searchParams, params }: { searchParams: Promise<{ coupon?: string | string[] }>, params: Promise<{ lang: string }> }) {

apps/website/src/app/[lang]/track/page.tsx

@@ -1,4 +1,5 @@
 import { MapPin } from 'lucide-react'
+import { generateSeoMetadata } from '@/lib/seo'
 
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import TrackOrderClient from '@/components/TrackOrderClient'
@@ -6,9 +7,14 @@ import { getCategoriesResult, getCmsPageResult } from '@/lib/cms'
 import { splitCmsLayoutSections } from '@/lib/cms-sections'
 
 // lang is extracted from params
-export const metadata = {
-  title: 'ติดตามคำสั่งซื้อ | HomAroma',
-  description: 'ตรวจสอบสถานะคำสั่งซื้อ HomAroma ด้วยหมายเลขคำสั่งซื้อและเบอร์โทรศัพท์ที่ใช้สั่งซื้อ',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'ติดตามคำสั่งซื้อ | HomAroma',
+    description: 'ตรวจสอบสถานะคำสั่งซื้อ HomAroma ด้วยหมายเลขคำสั่งซื้อและเบอร์โทรศัพท์ที่ใช้สั่งซื้อ',
+    path: '/track',
+    lang,
+  });
 }
 
 export default async function TrackPage({ params }: { params: Promise<{ lang: string }> }) {

apps/website/src/app/[lang]/wishlist/page.tsx

@@ -1,4 +1,5 @@
 import { Heart } from 'lucide-react'
+import { generateSeoMetadata } from '@/lib/seo'
 
 import DynamicPageRenderer from '@/components/dynamic/DynamicPageRenderer'
 import WishlistClient from '@/components/WishlistClient'
@@ -6,9 +7,14 @@ import { getCategoriesResult, getCmsPageResult } from '@/lib/cms'
 import { splitCmsLayoutSections } from '@/lib/cms-sections'
 
 // lang is extracted from params
-export const metadata = {
-  title: 'Wishlist | HomAroma',
-  description: 'รายการสินค้าที่คุณบันทึกไว้ใน Wishlist ของ HomAroma',
+export async function generateMetadata({ params }: { params: Promise<{ lang: string }> }) {
+  const { lang } = await params;
+  return generateSeoMetadata({
+    title: 'Wishlist | HomAroma',
+    description: 'รายการสินค้าที่คุณบันทึกไว้ใน Wishlist ของ HomAroma',
+    path: '/wishlist',
+    lang,
+  });
 }
 
 export default async function WishlistPage({ params }: { params: Promise<{ lang: string }> }) {

apps/website/src/app/robots.ts

@@ -7,7 +7,16 @@ export default function robots(): MetadataRoute.Robots {
     rules: {
       userAgent: '*',
       allow: '/',
-      disallow: ['/api/', '/_next/', '/profile/', '/checkout/', '/order/'],
+      disallow: [
+        '/api/',
+        '/_next/',
+        '/*/profile/',
+        '/*/checkout/',
+        '/*/order/',
+        '/profile/',
+        '/checkout/',
+        '/order/'
+      ],
     },
     sitemap: `${baseUrl}/sitemap.xml`,
   };

apps/website/src/components/AddToCartSection.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import { useState } from 'react'
-import Link from 'next/link'
+import Link from './LocalizedLink'
 import { getCategoryImage, formatPrice, type Product } from '@homaroma/types'
 import { useCartStore } from '../store/cartStore'
 import { resolveCategoryName, resolveLocalized } from '../lib/localization'

apps/website/src/components/CartDrawer.tsx

@@ -1,6 +1,6 @@
 "use client";
 import { X, ShoppingBag, Plus, Minus, Trash2 } from 'lucide-react'
-import Link from 'next/link'
+import Link from './LocalizedLink'
 import { useCartStore } from '../store/cartStore'
 import { formatPrice } from '@homaroma/types'
 import { useTranslation } from 'react-i18next'

apps/website/src/components/CheckoutClient.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import Link from 'next/link'
+import Link from './LocalizedLink'
 import { useRouter } from 'next/navigation'
 import { useEffect, useMemo, useState } from 'react'
 import { AlertCircle, CheckCircle2, Loader2, PackageCheck, ShoppingBag, Ticket, UserRound } from 'lucide-react'
@@ -9,6 +9,8 @@ import { formatPrice, type CartItem, type CustomerAddress } from '@homaroma/type
 import { API_BASE } from '../lib/api'
 import { useAuthStore, type Customer } from '../store/authStore'
 import { useCartStore } from '../store/cartStore'
+import { useLang } from '../hooks/useLang'
+import { getPathWithLocale } from '../lib/locales'
 
 type StoreSettings = {
   shippingFee?: number
@@ -115,6 +117,7 @@ function saveLocalOrder(orderId: number) {
 
 export default function CheckoutClient() {
   const router = useRouter()
+  const lang = useLang()
   const { customer } = useAuthStore()
   const { items, clearCart, getCartTotal } = useCartStore()
   const [hydrated, setHydrated] = useState(false)
@@ -373,7 +376,7 @@ export default function CheckoutClient() {
 
       clearCart()
       saveLocalOrder(order.id)
-      router.push(`/order/${order.id}`)
+      router.push(getPathWithLocale(`/order/${order.id}`, lang))
     } catch (error) {
       setSubmitError(error instanceof Error ? error.message : 'ไม่สามารถสร้างคำสั่งซื้อได้')
     } finally {

apps/website/src/components/Footer.tsx

@@ -23,7 +23,7 @@ export default function Footer({
   const { t } = useTranslation()
   const lang = useLang()
   const [mounted, setMounted] = useState(false)
-  useEffect(() => { setMounted(true) }, [])
+  useEffect(() => { queueMicrotask(() => setMounted(true)) }, [])
   // Before mount: always 'th' to match SSR output → no hydration mismatch
   // After mount:  real user language → correct content
   const effectiveLang = mounted ? lang : 'th'
@@ -32,7 +32,7 @@ export default function Footer({
   const translateMenuLabel = (item: MenuItem): string => {
     // Use outer `lang` from closure — hooks cannot be called inside nested functions
     if (effectiveLang !== 'en' && item.translations && item.translations.length > 0) {
-      const trans = item.translations.find((tr: any) => tr.langCode === effectiveLang)
+      const trans = item.translations.find((tr: { langCode: string; label: string }) => tr.langCode === effectiveLang)
       if (trans?.label) return trans.label
     }
     const map: Record<string, string> = {

apps/website/src/components/LocalizedLink.tsx

@@ -24,7 +24,7 @@ export default function LocalizedLink({
   // Extract current locale from pathname
   const currentLocale = useMemo(() => {
     const segments = pathname.split('/').filter(Boolean);
-    if (segments.length > 0 && SUPPORTED_LOCALES.includes(segments[0] as any)) {
+    if (segments.length > 0 && (SUPPORTED_LOCALES as readonly string[]).includes(segments[0])) {
       return segments[0];
     }
     return 'th'; // Fallback

apps/website/src/components/Navbar.tsx

@@ -32,6 +32,12 @@ const LANGUAGES = [
   { code: 'ko', label: '한국어', short: 'KO' },
 ]
 
+function setLanguageCookie(code: string) {
+  if (typeof document !== 'undefined') {
+    document.cookie = `homaroma_lang=${code}; path=/; max-age=31536000`
+  }
+}
+
 function createFallbackMenu(categories: Category[]): MegaMenuPayload[] {
   const categoryLinks = categories.map((category) => {
     // category.name is a multilingual Record<lang,string> when fetched with lang=all
@@ -90,13 +96,13 @@ export default function Navbar({ categories = [], initialMenu = [], settings = n
   const changeLanguage = (code: string) => {
     i18n.changeLanguage(code)
     localStorage.setItem('homaroma_lang', code)
-    document.cookie = `homaroma_lang=${code}; path=/; max-age=31536000`
+    setLanguageCookie(code)
     
     const currentPathWithoutLang = getPathWithoutLocale(pathname)
     const newPath = getPathWithLocale(currentPathWithoutLang, code)
     
     setLangSheetOpen(false)
-    router.push(newPath)
+    router.push(newPath + window.location.search)
   }
 
   const loginWithLine = () => {
@@ -105,7 +111,7 @@ export default function Navbar({ categories = [], initialMenu = [], settings = n
       maybeWindow.liff.login()
       return
     }
-    router.push('/profile')
+    router.push(getPathWithLocale('/profile', lang))
   }
 
 
@@ -163,7 +169,7 @@ export default function Navbar({ categories = [], initialMenu = [], settings = n
   const handleSearch = (e: React.FormEvent) => {
     e.preventDefault()
     if (searchQuery.trim()) {
-      router.push(`/search?q=${encodeURIComponent(searchQuery.trim())}`)
+      router.push(getPathWithLocale(`/search?q=${encodeURIComponent(searchQuery.trim())}`, lang))
       setSearchOpen(false)
       setMobileOpen(false)
       setSearchQuery('')

apps/website/src/components/ProductCard.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import Link from 'next/link'
+import Link from './LocalizedLink'
 import type { Product } from '@homaroma/types'
 import { getCategoryImage, formatPrice } from '@homaroma/types'
 import { resolveCategoryName, resolveLocalized } from '../lib/localization'

apps/website/src/components/ProfileClient.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import Link from 'next/link'
+import Link from './LocalizedLink'
 import { useEffect, useState } from 'react'
 import {
   Award,

apps/website/src/components/ShopCouponBridge.tsx

@@ -2,6 +2,8 @@
 
 import { useEffect } from 'react'
 import { useRouter } from 'next/navigation'
+import { useLang } from '../hooks/useLang'
+import { getPathWithLocale } from '../lib/locales'
 
 type ShopCouponBridgeProps = {
   coupon?: string
@@ -9,13 +11,14 @@ type ShopCouponBridgeProps = {
 
 export default function ShopCouponBridge({ coupon }: ShopCouponBridgeProps) {
   const router = useRouter()
+  const lang = useLang()
 
   useEffect(() => {
     if (!coupon) return
 
     localStorage.setItem('homaroma_active_coupon', coupon)
-    router.replace('/shop', { scroll: false })
-  }, [coupon, router])
+    router.replace(getPathWithLocale('/shop', lang), { scroll: false })
+  }, [coupon, router, lang])
 
   return null
 }

apps/website/src/components/TrackOrderClient.tsx

@@ -1,11 +1,13 @@
 "use client";
 
-import Link from 'next/link'
+import Link from './LocalizedLink'
 import { useRouter } from 'next/navigation'
 import { useEffect, useState } from 'react'
 import { ChevronRight, Loader2, Package, Search } from 'lucide-react'
 
 import { API_BASE } from '../lib/api'
+import { useLang } from '../hooks/useLang'
+import { getPathWithLocale } from '../lib/locales'
 
 type TrackResponse =
   | { success: true; orderId: number }
@@ -30,6 +32,7 @@ function orderLabel(id: number) {
 
 export default function TrackOrderClient() {
   const router = useRouter()
+  const lang = useLang()
   const [orderId, setOrderId] = useState('')
   const [phone, setPhone] = useState('')
   const [localOrders, setLocalOrders] = useState<number[]>([])
@@ -75,7 +78,7 @@ export default function TrackOrderClient() {
 
       if (response.ok && 'success' in data && data.success) {
         saveLocalOrder(data.orderId)
-        router.push(`/order/${data.orderId}`)
+        router.push(getPathWithLocale(`/order/${data.orderId}`, lang))
         return
       }
 

apps/website/src/components/WishlistClient.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import Link from 'next/link'
+import Link from './LocalizedLink'
 import { Heart } from 'lucide-react'
 
 import ProductCard from './ProductCard'

apps/website/src/components/dynamic/DynamicPageRenderer.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import Link from 'next/link'
+import Link from '../LocalizedLink'
 import { Clock, Mail, MapPin, MessageCircle } from 'lucide-react'
 import type { Category, PageSection, Product } from '@homaroma/types'
 import { getCategoryImage } from '@homaroma/types'

apps/website/src/hooks/useLang.ts

@@ -14,7 +14,7 @@ export function useLang(): string {
   return useMemo(() => {
     // 1. Try to get it from route params
     if (params?.lang && typeof params.lang === 'string') {
-      if (SUPPORTED_LOCALES.includes(params.lang as any)) {
+      if ((SUPPORTED_LOCALES as readonly string[]).includes(params.lang)) {
         return params.lang;
       }
     }
@@ -22,7 +22,7 @@ export function useLang(): string {
     // 2. Fallback: extract from pathname if params are not available yet
     if (pathname) {
       const segments = pathname.split('/').filter(Boolean);
-      if (segments.length > 0 && SUPPORTED_LOCALES.includes(segments[0] as any)) {
+      if (segments.length > 0 && (SUPPORTED_LOCALES as readonly string[]).includes(segments[0])) {
         return segments[0];
       }
     }

apps/website/src/lib/seo.ts

@@ -0,0 +1,38 @@
+import { Metadata } from 'next';
+import { SUPPORTED_LOCALES } from './locales';
+
+const baseUrl = process.env.NEXT_PUBLIC_SITE_URL || 'http://localhost:3000';
+
+type SeoMetadataProps = {
+  title: string;
+  description: string;
+  path: string; // e.g. '/shop', '/category/1', or ''
+  lang: string;
+  openGraph?: Metadata['openGraph'];
+};
+
+export function generateSeoMetadata({
+  title,
+  description,
+  path,
+  lang,
+  openGraph,
+}: SeoMetadataProps): Metadata {
+  const cleanPath = path.startsWith('/') ? path : `/${path}`;
+  const pathPart = cleanPath === '/' ? '' : cleanPath;
+  
+  const languages: Record<string, string> = {};
+  SUPPORTED_LOCALES.forEach((locale) => {
+    languages[locale] = `${baseUrl}/${locale}${pathPart}`;
+  });
+
+  return {
+    title,
+    description,
+    alternates: {
+      canonical: `${baseUrl}/${lang}${pathPart}`,
+      languages,
+    },
+    openGraph,
+  };
+}

apps/website/src/proxy.ts

@@ -31,15 +31,15 @@ export function proxy(request: NextRequest) {
   const cookieLocale = request.cookies.get('homaroma_lang')?.value;
   let targetLocale = DEFAULT_LOCALE;
 
-  if (cookieLocale && SUPPORTED_LOCALES.includes(cookieLocale as any)) {
-    targetLocale = cookieLocale as any;
+  if (cookieLocale && (SUPPORTED_LOCALES as readonly string[]).includes(cookieLocale)) {
+    targetLocale = cookieLocale as typeof SUPPORTED_LOCALES[number];
   } else {
     // 2. Check Accept-Language header
     const acceptLang = request.headers.get('accept-language');
     if (acceptLang) {
       const preferred = acceptLang.split(',')[0].split('-')[0].toLowerCase();
-      if (SUPPORTED_LOCALES.includes(preferred as any)) {
-        targetLocale = preferred as any;
+      if ((SUPPORTED_LOCALES as readonly string[]).includes(preferred)) {
+        targetLocale = preferred as typeof SUPPORTED_LOCALES[number];
       }
     }
   }