Support for charging a one-time fee during a free trial (e.g., "$1 Trial")
I want to implement a "$1 Trial" for my SaaS where the user pays $1 upfront, gets 24-hour trial access, and then is auto-charged the full subscription price ($69/mo) after the trial. This is important for qualifying trial users and reducing fraud. I need this functionality, similar to Stripe's add_invoice_items, to charge a one-time fee during the free trial period.