feat: site search with a dialog in the header and a /api/busca endpoint

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/api/busca/route.js

@@ -0,0 +1,12 @@
+import { construirIndiceBusca } from "@/lib/searchIndex";
+
+export const dynamic = "force-static";
+
+/** Índice de busca carregado sob demanda pelo diálogo de pesquisa (Ctrl/⌘+K). */
+export function GET() {
+	return Response.json(construirIndiceBusca(), {
+		headers: {
+			"Cache-Control": "no-cache, no-store, must-revalidate",
+		},
+	});
+}