perf(web): [locale] 트리 ISR 화 — 홈 매 요청 dynamic 제거 (#942)

packages/web/app/[locale]/(shell)/__tests__/home-locale-prefetch.test.tsx

@@ -5,6 +5,13 @@ vi.mock("@/lib/components/home/HomeShell", () => ({
   HomeShell: () => null,
 }));
 
+// `setRequestLocale` (static-render enabler) resolves to next-intl's
+// client build under vitest and throws "not supported in Client Components".
+// It's orthogonal to locale propagation — no-op it here.
+vi.mock("next-intl/server", () => ({
+  setRequestLocale: vi.fn(),
+}));
+
 // Spy on the server fetch util; route by path so each helper gets a usable shape.
 const { serverApiGet } = vi.hoisted(() => ({
   serverApiGet: vi.fn(async (path: string, _options?: { locale?: string }) => {
@@ -27,7 +34,6 @@ describe("Home RSC prefetch locale propagation (#838)", () => {
 
     await Home({
       params: Promise.resolve({ locale: "ko" }),
-      searchParams: Promise.resolve({}),
     });
 
     expect(serverApiGet.mock.calls.length).toBeGreaterThan(0);
@@ -41,7 +47,6 @@ describe("Home RSC prefetch locale propagation (#838)", () => {
 
     await Home({
       params: Promise.resolve({ locale: "en" }),
-      searchParams: Promise.resolve({}),
     });
 
     for (const [, options] of serverApiGet.mock.calls) {

packages/web/app/[locale]/(shell)/layout.tsx

@@ -1,9 +1,17 @@
+import { setRequestLocale } from "next-intl/server";
 import { AppShell } from "@/lib/components/shell/AppShell";
 
-export default function ShellLayout({
+export default async function ShellLayout({
   children,
+  params,
 }: {
   children: React.ReactNode;
+  params: Promise<{ locale: string }>;
 }) {
+  // 정적 렌더에는 [locale] 트리의 모든 layout·page 가 setRequestLocale 을
+  // 호출해야 한다 — 하나라도 빠지면 세그먼트가 dynamic 으로 떨어진다(#942).
+  const { locale } = await params;
+  setRequestLocale(locale);
+
   return <AppShell>{children}</AppShell>;
 }

packages/web/app/[locale]/(shell)/page.tsx

@@ -18,6 +18,7 @@ import type {
   CurationListResponse,
   FeedItem,
 } from "@/lib/api/generated/models";
+import { setRequestLocale } from "next-intl/server";
 import { serverApiGet } from "@/lib/api/server-instance";
 import { isLocale, type Locale } from "@/lib/i18n/locale";
 import { getPostMatch } from "@/lib/api/adapters/postMatch";
@@ -188,18 +189,18 @@ async function fetchHeroSlides(
 
 export default async function Home({
   params,
-  searchParams,
 }: {
   params: Promise<{ locale: string }>;
-  searchParams: Promise<{ variant?: string }>;
 }) {
   const { locale: rawLocale } = await params;
+  // Enable static rendering — every layout/page in the [locale] tree must call
+  // this or the segment falls back to on-demand dynamic (#942).
+  setRequestLocale(rawLocale);
   // params.locale is a raw string; narrow to Locale so serverApiGet forwards
   // the request locale (invalid values fall back to the util's RENDERED_LOCALE).
   const locale: Locale | undefined = isLocale(rawLocale)
     ? rawLocale
     : undefined;
-  await searchParams;
 
   const [popularPosts, recentPosts, moodPool, artistProfileMap, curations] =
     await Promise.all([

packages/web/app/[locale]/layout.tsx

@@ -4,6 +4,18 @@ import { notFound } from "next/navigation";
 import { routing } from "@/i18n/routing";
 import { LazyTasteOnboardingPrompt } from "@/lib/components/onboarding/LazyTasteOnboardingPrompt";
 
+// 빌드타임에 locale 을 확정해 [locale] 트리를 정적/ISR 렌더 가능하게 한다
+// (없으면 Next 가 세그먼트 전체를 on-demand dynamic 으로 처리 — #942).
+export function generateStaticParams() {
+  return routing.locales.map((locale) => ({ locale }));
+}
+
+// 앱 전체 canonical 타임존. next-intl 포매터를 서버/클라 어디서도 쓰지 않으므로
+// (날짜 "time ago" 는 컴포넌트에서 수동 계산) 이 값은 렌더 결과에 영향이 없고,
+// 오직 NextIntlClientProvider 의 정적 렌더 조건(locale·now·timeZone 명시)을
+// 충족시키기 위한 것이다 — ko-first 제품에 맞춰 Asia/Seoul 로 고정.
+const APP_TIME_ZONE = "Asia/Seoul";
+
 export default async function LocaleLayout({
   children,
   modal,
@@ -18,7 +30,13 @@ export default async function LocaleLayout({
   setRequestLocale(locale);
 
   return (
-    <NextIntlClientProvider>
+    // locale·now·timeZone 을 명시해야 provider 가 정적 렌더된다 — 명시하지
+    // 않으면 next-intl 이 이 트리를 dynamic 으로 opt-in 시킨다(#942).
+    <NextIntlClientProvider
+      locale={locale}
+      now={new Date()}
+      timeZone={APP_TIME_ZONE}
+    >
       {children}
       {modal}
       {/* 로그인 유저 taste 넛지 — next-intl 컨텍스트가 필요해 [locale] 레이아웃