feat: add PaypalPaymentGateway implementation gated by payment.provider setting

Author: otaviojava

cdi-api/src/main/java/com/otavio/jakarta/cdi/app/PaypalPaymentGateway.java

@@ -0,0 +1,14 @@
+package com.otavio.jakarta.cdi.app;
+
+import com.otavio.jakarta.cdi.RequiresSetting;
+import jakarta.enterprise.context.ApplicationScoped;
+
+@RequiresSetting(name = "payment.provider", value = "paypal")
+@ApplicationScoped
+public class PaypalPaymentGateway implements PaymentGateway {
+
+    @Override
+    public void pay() {
+        System.out.println("Processing payment with PayPal");
+    }
+}