feat: 支付成功页与友好 webhook 落地页

浏览器回跳展示许可证并深链回 App；补齐包年订单因未收到 Waffo POST 未发码的体验。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/internal/service/payment/waffo.go

@@ -29,7 +29,7 @@ func LoadWaffoConfig() WaffoConfig {
 	}
 	success := strings.TrimSpace(os.Getenv("SUCCESS_URL"))
 	if success == "" {
-		success = "opsxshell://pro/activated"
+		success = "http://l123.91ai.io/api/v1/purchase/success"
 	}
 	currency := strings.TrimSpace(os.Getenv("WAFFO_CURRENCY"))
 	if currency == "" {