feat(i18n): routing and localization infrastructure (phase 1)

Implement Phase 1 of i18n spec:
- Configure next-intl with 6 locales (pt, en, es, fr, de, zh-CN) and pathnames
- Move routes to app/[locale] structure with localized layouts and metadata
- Add middleware for root language negotiation (307), legacy redirects (308), and 404 for non-pt book
- Implement language selector dropdown in header with cookie persistence
- Add system typography rules for zh-CN and word-break/hyphenation for de/fr

Co-Authored-By: Antigravity <noreply@google.com>

app/[locale]/catalogo/layout.jsx

@@ -0,0 +1,39 @@
+import { paginaMeta, jsonLd } from "@/lib/seo";
+
+export const metadata = paginaMeta({
+	titulo: "Catálogo de placas ESP32",
+	descricao: "Placas de desenvolvimento com ESP32 disponíveis no Brasil, com filtro por série, conector e conversor USB-serial.",
+	caminho: "/catalogo",
+	keywords: ["placas ESP32", "DevKit ESP32", "comprar ESP32", "ESP32 DevKitC"],
+});
+
+export default function Layout({ children }) {
+	return (
+		<>
+			<script
+				type="application/ld+json"
+				dangerouslySetInnerHTML={{
+					__html: JSON.stringify(
+						jsonLd.aplicacaoWeb({
+							nome: "Catálogo de Placas ESP32",
+							descricao: "Guia e catálogo interativo de placas de desenvolvimento e DevKits com microcontroladores ESP32.",
+							caminho: "/catalogo",
+						})
+					),
+				}}
+			/>
+			<script
+				type="application/ld+json"
+				dangerouslySetInnerHTML={{
+					__html: JSON.stringify(
+						jsonLd.trilha([
+							{ nome: "Início", caminho: "/" },
+							{ nome: "Catálogo de Placas", caminho: "/catalogo" },
+						])
+					),
+				}}
+			/>
+			{children}
+		</>
+	);
+}