Run copier update with payment_provider=paddle to switch all billing
integration: routes, config, schema columns, webhook handling, tests,
and CI deploy secrets. Add one-time migration script for renaming
lemonsqueezy_* columns to paddle_* in production DB.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Update from materia_saas_boilerplate template with payment_provider=lemonsqueezy.
Adds full LemonSqueezy billing routes (checkout, webhooks, subscription management),
HMAC webhook verification, subscriptions/API keys schema, and removes Caddy in favor
of Nginx Proxy Manager.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
