fix: map plan names to correct Stripe price IDs

- Add PLAN_NAME_TO_STRIPE_ID mapping helper
- Maps: Chat IA → essential, Chat + Voz → profesional, Empresa IA → premium
- Fixes bug where wrong plan IDs were sent to Stripe (e.g. 'chat ia' instead of 'essential')
- Test calls verified for all 3 tiers across verticals

app/demos/page.tsx

@@ -11,6 +11,27 @@ type Language = "es" | "en";
 type Vertical = "real-estate" | "restaurant" | "clinic" | "home-services" | "car-rental";
 type Location = "generic" | "benalmadena";
 
+// Map internal plan names to Stripe price IDs
+// Essential = Chat IA / AI Chat (€299)
+// Profesional = Chat + Voz / Chat + Voice (€599)  
+// Premium = Empresa IA / AI Company (€1,499)
+const PLAN_NAME_TO_STRIPE_ID: Record<string, string> = {
+  // Spanish
+  "chat ia": "essential",
+  "chat + voz": "profesional",
+  "empresa ia": "premium",
+  // English
+  "ai chat": "essential",
+  "chat + voice": "profesional",
+  "ai company": "premium",
+};
+
+function getStripePlanId(planName: string, vertical: string): string {
+  const normalizedName = planName.toLowerCase().trim();
+  const tier = PLAN_NAME_TO_STRIPE_ID[normalizedName] || "essential";
+  return `demo-${vertical}-${tier}`;
+}
+
 const contentByLang = {
   es: {
     nav: { features: "Características", pricing: "Precios", contact: "Contacto", cta: "Pedir demo" },
@@ -473,7 +494,7 @@ function DemosContent() {
                   ))}
                 </ul>
                 <PaymentButton 
-                  planId={`demo-${selected}-${plan.name.toLowerCase().replace("starter", "starter").replace("site", "site").replace("growth", "growth")}`} 
+                  planId={getStripePlanId(plan.name, selected)} 
                   planType="monthly" 
                   label={lang === "es" ? "Elegir plan" : "Choose plan"}
                   variant={plan.popular ? "primary" : "secondary"}