Invoice payment-failed notification (MAIL-09).
Sent when Stripe emits invoice.payment_failed. Body contains a CTA
pointing at @context.invoice.hosted_invoice_url (the Stripe-hosted
pay-now page) so the customer can complete payment without Accrue
hosting its own payment surface. Does NOT attach a PDF — the PDF is
not available until the invoice is paid.
Summary
Functions
Returns the raw MJML template. Useful for debugging rendering issues.
Safely render the MJML template using Phoenix.HTML