What is payment-integration?
Load PROACTIVELY when task involves payments, billing, or subscriptions. Use when user says "add payments", "integrate Stripe", "set up subscriptions", "add a checkout flow", or "handle billing webhooks". Covers Stripe, LemonSqueezy, and Paddle integration, checkout sessions, subscription lifecycle management, webhook verification and handling, customer portal, metered billing, refunds, and PCI compliance considerations. Source: mgd34msu/goodvibes-plugin.