feat: initial commit — asaas-checkout template white-label

Template genérico de checkout com ASAAS, parametrizado via env vars.
Inclui fluxo completo: checkout → pedido → polling → webhook → admin.

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

lib/config.ts

@@ -0,0 +1,11 @@
+// Configurações da instância — todas via variáveis de ambiente
+// Copie .env.example para .env.local e preencha
+
+export const appConfig = {
+  name: process.env.NEXT_PUBLIC_APP_NAME ?? "Checkout",
+  logoUrl: process.env.NEXT_PUBLIC_APP_LOGO_URL ?? null,
+  primaryColor: process.env.NEXT_PUBLIC_APP_PRIMARY_COLOR ?? "#1d4ed8",
+  supportEmail: process.env.NEXT_PUBLIC_SUPPORT_EMAIL ?? null,
+  supportWhatsapp: process.env.NEXT_PUBLIC_SUPPORT_WHATSAPP ?? null,
+  afterPaymentRedirect: process.env.NEXT_PUBLIC_AFTER_PAYMENT_REDIRECT ?? null,
+}