feat(i18n): French and German localization (phase 5)

- Add full message catalogs and content for French (fr) and German (de)
- Implement ASCII canonical slugs for French and German routes
- Add language-specific search endpoints (/api/busca/fr, /api/busca/de)
- Configure strict 404 responses for /fr/livro and /de/livro
- Localize SEO, OpenGraph (fr_FR, de_DE), Twitter and JSON-LD schemas
- Add localized code example comments across 14 examples for fr and de
- Enable 'fr' and 'de' in ENABLED_LOCALES with root negotiation and redirect
- Extend test suite in check-i18n, smoke-imagem and verifica-vazamentos

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

app/[locale]/not-found.jsx

@@ -31,6 +31,20 @@ const CAMINHOS_ES = [
 	{ href: "/glossario", icon: BookOpen, titulo: "Glosario", texto: "Términos de hardware explicados con claridad." },
 ];
 
+const CAMINHOS_FR = [
+	{ href: "/series", icon: Compass, titulo: "Séries ESP32", texto: "Les 12 familles, avec brochage et spécifications." },
+	{ href: "/seletor", icon: SlidersHorizontal, titulo: "Sélecteur de puce", texto: "Répondez à huit questions et obtenez les modèles recommandés." },
+	{ href: "/comparacao", icon: Scale, titulo: "Comparateur", texto: "Jusqu'à quatre séries côte à côte." },
+	{ href: "/glossario", icon: BookOpen, titulo: "Glossaire", texto: "Les termes matériels expliqués clairement." },
+];
+
+const CAMINHOS_DE = [
+	{ href: "/series", icon: Compass, titulo: "ESP32-Serien", texto: "Die 12 Familien mit Pinbelegung und Spezifikationen." },
+	{ href: "/seletor", icon: SlidersHorizontal, titulo: "Chip-Auswahl", texto: "Beantworten Sie acht Fragen und erhalten Sie passende Empfehlungen." },
+	{ href: "/comparacao", icon: Scale, titulo: "Vergleich", texto: "Bis zu vier Serien im direkten Vergleich." },
+	{ href: "/glossario", icon: BookOpen, titulo: "Glossar", texto: "Hardware-Begriffe verständlich erklärt." },
+];
+
 export default async function NotFound() {
 	let locale = "pt";
 	try {
@@ -40,7 +54,9 @@ export default async function NotFound() {
 	}
 	const isEn = locale === "en";
 	const isEs = locale === "es";
-	const caminhos = isEn ? CAMINHOS_EN : isEs ? CAMINHOS_ES : CAMINHOS_PT;
+	const isFr = locale === "fr";
+	const isDe = locale === "de";
+	const caminhos = isEn ? CAMINHOS_EN : isEs ? CAMINHOS_ES : isFr ? CAMINHOS_FR : isDe ? CAMINHOS_DE : CAMINHOS_PT;
 
 	return (
 		<div className="site-canvas min-h-screen">
@@ -48,18 +64,22 @@ export default async function NotFound() {
 
 			<main id="conteudo" className="shell section">
 				<div className="mx-auto max-w-2xl text-center">
-					<p className="eyebrow justify-center">{isEn ? "Error 404" : "Error 404"}</p>
-					<h1 className="page-title mt-4">{isEn ? "This page does not exist." : isEs ? "Esta página no existe." : "Essa página não existe."}</h1>
+					<p className="eyebrow justify-center">{isEn ? "Error 404" : isFr ? "Erreur 404" : isDe ? "Fehler 404" : "Error 404"}</p>
+					<h1 className="page-title mt-4">{isEn ? "This page does not exist." : isEs ? "Esta página no existe." : isFr ? "Cette page n'existe pas." : isDe ? "Diese Seite existiert nicht." : "Essa página não existe."}</h1>
 					<p className="lede mx-auto mt-5 max-w-xl">
 						{isEn
 							? "The address may have changed or was mistyped. Choose one of these paths to continue."
 							: isEs
 							? "La dirección puede haber cambiado o estar mal escrita. Elija uno de estos caminos para continuar."
+							: isFr
+							? "L'adresse a peut-être changé ou a été mal saisie. Choisissez l'un de ces chemins pour continuer."
+							: isDe
+							? "Die Adresse wurde möglicherweise geändert oder falsch eingegeben. Wählen Sie einen dieser Wege, um fortzufahren."
 							: "O endereço pode ter mudado ou estar digitado errado. Escolha um destes caminhos para continuar."}
 					</p>
 					<div className="mt-8 flex justify-center">
-						<Link href={isEn ? "/en" : isEs ? "/es" : "/"} className="btn btn-primary">
-							{isEn ? "Back to home" : isEs ? "Volver al inicio" : "Voltar ao início"}
+						<Link href={isEn ? "/en" : isEs ? "/es" : isFr ? "/fr" : isDe ? "/de" : "/"} className="btn btn-primary">
+							{isEn ? "Back to home" : isEs ? "Volver al inicio" : isFr ? "Retour à l'accueil" : isDe ? "Zur Startseite" : "Voltar ao início"}
 							<ArrowRight className="h-4 w-4" aria-hidden="true" />
 						</Link>
 					</div>