fix: restore ISR on public pages — isolate DYNAMIC_SERVER_USAGE root cause

Root cause: next-intl's getMessages/getTranslations internally resolves
requestLocale by reading cookies/headers, which trips DYNAMIC_SERVER_USAGE
under ISR. Fixed by calling setRequestLocale(locale) in layout + every
public page — caches the locale in React cache so next-intl never reads
cookies.

Changes:
- [locale]/layout.tsx: +setRequestLocale, +generateStaticParams (5 locales),
  wrap NavigationManager in <Suspense> (uses useSearchParams)
- 5 public pages: force-dynamic → revalidate=60, +setRequestLocale
- HQ dashboard pages: unchanged (still force-dynamic for auth)

Build verified: home/heritage/news pre-render as SSG with 1m revalidation,
slug pages render on-demand with ISR cache. Nginx s-maxage=60 remains as
safety net. Zero DYNAMIC_SERVER_USAGE errors.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -1,5 +1,5 @@
-// Force-dynamic — see /[locale]/page.tsx for the rationale.
-export const dynamic = "force-dynamic";
+// ISR: revalidate every 60s — see /[locale]/page.tsx for the full rationale.
+export const revalidate = 60;
 
 import type { Metadata } from "next";
 import Link from "next/link";
@@ -9,6 +9,7 @@ import { prisma } from "@/lib/prisma";
 import { notFound } from "next/navigation";
 import ApplicationClient from "./ApplicationClient";
 
+import { setRequestLocale } from "next-intl/server";
 import { getLocalizedData } from "@/lib/i18nHelper";
 import {
   buildPageMetadata,
@@ -82,16 +83,15 @@ export async function generateMetadata({
   }
 }
 
-// generateStaticParams intentionally omitted — combined with
-// `dynamic = "force-dynamic"`, this guarantees pure SSR per request.
-// Having it (even returning [] in prod) made Next.js classify the
-// route as SSG-eligible, which conflicted with dynamic API reads
-// elsewhere in the tree and surfaced as DYNAMIC_SERVER_USAGE errors.
+// generateStaticParams omitted — slug pages render on-demand and are cached
+// by ISR (revalidate=60). The DYNAMIC_SERVER_USAGE issue that previously
+// blocked this is now fixed via setRequestLocale.
 
 // 🔥 AHORA RECIBIMOS EL LOCALE DESDE LA URL
 export default async function ApplicationPage({ params }: { params: Promise<{ slug: string, locale: string }> }) {
   const resolvedParams = await params;
   const { slug, locale } = resolvedParams;
+  setRequestLocale(locale);
 
   // 1. Buscamos la Teoría General de la Aplicación
   let rawData: any = null;

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

@@ -1,5 +1,6 @@
-// Force-dynamic — see /[locale]/page.tsx for the rationale.
-export const dynamic = "force-dynamic";
+// ISR: revalidate every 60s — see /[locale]/page.tsx for the full rationale.
+// setRequestLocale caches the locale so next-intl doesn't read cookies/headers.
+export const revalidate = 60;
 
 import type { Metadata } from "next";
 import Link from "next/link";
@@ -11,7 +12,7 @@ import AutoPlayVideo from "@/components/AutoPlayVideo";
 
 // 🔥 IMPORTACIONES DE IDIOMAS
 import { getLocalizedData } from "@/lib/i18nHelper";
-import { getTranslations } from "next-intl/server";
+import { getTranslations, setRequestLocale } from "next-intl/server";
 import { buildPageMetadata } from "@/lib/seo";
 
 export async function generateMetadata({
@@ -197,7 +198,7 @@ export default async function HeritagePage({ params }: { params: Promise<{ local
   const resolvedParams = await params;
   const locale = resolvedParams.locale;
 
-  // Pass locale explicitly so getTranslations stays static-friendly under ISR.
+  setRequestLocale(locale);
   const t = await getTranslations({ locale, namespace: "HeritagePage" });
 
   let rawSections: any[] = [];

src/app/[locale]/layout.tsx

@@ -1,4 +1,5 @@
 import type { Metadata, Viewport } from "next";
+import { Suspense } from "react";
 import { Inter } from "next/font/google";
 import "../globals.css";
 
@@ -9,9 +10,15 @@ import Footer from "@/components/layout/Footer";
 import CartDrawer from "@/components/layout/CartDrawer";
 
 import { NextIntlClientProvider } from 'next-intl';
-import { getMessages } from 'next-intl/server';
+import { getMessages, setRequestLocale } from 'next-intl/server';
 import { notFound } from 'next/navigation';
 import { routing } from '@/i18n/routing';
+
+// Pre-render all 5 locale variants at build time so Next.js knows which
+// [locale] segments are valid. Required for ISR to work with next-intl.
+export function generateStaticParams() {
+  return routing.locales.map((locale) => ({ locale }));
+}
 import { getBranding, getSocialLinks } from '@/lib/siteSettings';
 import { organizationSchema, websiteSchema } from '@/lib/seo';
 import JsonLd from '@/components/seo/JsonLd';
@@ -116,6 +123,10 @@ export default async function RootLayout({
     notFound();
   }
 
+  // Cache the locale so next-intl resolves it from memory instead of
+  // reading cookies/headers — this is what allows ISR on child pages.
+  setRequestLocale(locale);
+
   const [messages, branding, social] = await Promise.all([
     getMessages({ locale }),
     getBranding(),
@@ -153,7 +164,10 @@ export default async function RootLayout({
 
           <CartDrawer />
 
+          {/* Suspense boundary required for useSearchParams() under ISR */}
+          <Suspense fallback={null}>
             <NavigationManager />
+          </Suspense>
 
           <div className="flex-grow w-full flex flex-col relative">
             {children}

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

@@ -1,5 +1,5 @@
-// Force-dynamic — see /[locale]/page.tsx for the rationale.
-export const dynamic = "force-dynamic";
+// ISR: revalidate every 60s — see /[locale]/page.tsx for the full rationale.
+export const revalidate = 60;
 
 import type { Metadata } from "next";
 import Link from "next/link";
@@ -8,6 +8,7 @@ import { prisma } from "@/lib/prisma";
 import { ArrowLeft, Calendar, Tag, Linkedin } from "lucide-react";
 import BreathingField from "@/components/visuals/BreathingField";
 
+import { setRequestLocale } from "next-intl/server";
 import { getLocalizedData } from "@/lib/i18nHelper";
 import {
   buildPageMetadata,
@@ -47,8 +48,9 @@ export async function generateMetadata({
   }
 }
 
-// generateStaticParams intentionally omitted — see /[locale]/page.tsx
-// for the rationale.
+// generateStaticParams omitted — slug pages render on-demand and are cached
+// by ISR (revalidate=60). The DYNAMIC_SERVER_USAGE issue is fixed via
+// setRequestLocale.
 
 // ── SÚPER PARSER MARKDOWN (Con Tablas, Imágenes y Dark/Light Mode) ──
 // ... (El código del Súper Parser se queda IGUAL, no te preocupes) ...
@@ -213,6 +215,7 @@ const renderMarkdown = (text: string) => {
 export default async function ArticlePage({ params }: { params: Promise<{ slug: string, locale: string }> }) {
   const resolvedParams = await params;
   const { slug, locale } = resolvedParams;
+  setRequestLocale(locale);
 
   let rawArticle: any = null;
   try {

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

@@ -6,11 +6,11 @@ import { Newspaper, ArrowRight, Calendar } from "lucide-react";
 import BreathingField from "@/components/visuals/BreathingField";
 
 import { getLocalizedData } from "@/lib/i18nHelper";
-import { getTranslations } from "next-intl/server";
+import { getTranslations, setRequestLocale } from "next-intl/server";
 import { buildPageMetadata } from "@/lib/seo";
 
-// Force-dynamic — see /[locale]/page.tsx for the rationale.
-export const dynamic = "force-dynamic";
+// ISR: revalidate every 60s — see /[locale]/page.tsx for the full rationale.
+export const revalidate = 60;
 
 export async function generateMetadata({
   params,
@@ -31,7 +31,7 @@ export default async function NewsHub({ params }: { params: Promise<{ locale: st
   const resolvedParams = await params;
   const locale = resolvedParams.locale;
 
-  // Pass locale explicitly so getTranslations stays static-friendly under ISR.
+  setRequestLocale(locale);
   const t = await getTranslations({ locale, namespace: "NewsHub" });
 
   let rawArticles: any[] = [];

src/app/[locale]/page.tsx

@@ -15,17 +15,16 @@ import ApplicationsDeep from "@/components/sections/ApplicationsDeep";
 import HeroReel from "@/components/sections/HeroReel";
 import WhatWeDo from "@/components/sections/WhatWeDo";
 
+import { setRequestLocale } from "next-intl/server";
 import { buildPageMetadata } from "@/lib/seo";
 import { getBranding } from "@/lib/siteSettings";
 
-// Force-dynamic — there's an interaction between next-intl 4, Prisma client,
-// and Next.js 16 standalone that intermittently leaks dynamic API reads
-// (cookies / headers) through Server Components and trips DYNAMIC_SERVER_USAGE
-// under ISR. Caching is still effective at the Nginx layer (max-age=300 on
-// /_next/image and asset routes), and metadata is still recomputed per request
-// via generateMetadata. We can move back to ISR per-page once we've isolated
-// the offending dynamic read.
-export const dynamic = "force-dynamic";
+// ISR: revalidate every 60s. The DYNAMIC_SERVER_USAGE issue was caused by
+// next-intl internally reading cookies/headers to resolve the locale.
+// Fixed by calling setRequestLocale(locale) which caches the locale in
+// React cache, preventing the dynamic API read. Nginx also caches with
+// s-maxage=60 + stale-while-revalidate=300 as a safety net.
+export const revalidate = 60;
 
 const TITLES: Record<string, string> = {
   en: "FLUX | Solid-State RF Industrial Solutions",
@@ -63,6 +62,7 @@ export async function generateMetadata({
 // ✅ Next.js 16: params es Promise y DEBE ser awaiteado
 export default async function Home({ params }: { params: Promise<{ locale: string }> }) {
   const { locale } = await params;
+  setRequestLocale(locale);
 
   // --- 1. SLIDES DEL HERO (CMS-managed via HeroSlide model, fallback to filesystem) ---
   let heroSlides: Array<{