I need Cashfree’s Subscription API woven into my existing platform so customers can sign up, pay on a recurring basis, and receive automated billing reminders without any manual intervention from my side. The key requirement is the ability to create and manage several custom subscription plans—different prices, billing cycles, and trial periods—directly through the Cashfree backend and surfaced seamlessly in my UI. Your work should cover the full flow: secure customer checkout, tokenized card storage, webhook handling for renewals / failures, and the email or SMS reminders that Cashfree allows. Please deliver clean, well-commented code plus a brief setup guide so I can reproduce the integration on staging and production. If you have completed Cashfree subscriptions before, especially with custom plans and automated notifications, that experience will be highly valuable.