Create Stripe Checkout Product Id

Create a Stripe Checkout session for a one-off product purchase.

This endpoint creates a payment session (not a subscription) for purchasing a specific product by product ID. Used for star shop purchases and other one-time product purchases.

Args: request: JSON body with: - product_id: Stripe product ID (required) - user_id: User ID for metadata tracking (required) - user_email: Customer email address (required) - success_url: URL to redirect to on successful payment (optional) - cancel_url: URL to redirect to on payment cancellation (optional)

Returns: Checkout session details with secure URL