Purchase flow: name -> placeholder -> configure via the shipped PlanConfigurator -> Paddle overlay with custom_data -> paste install UUID to link and issue. lineItemsFor mirrors the Go catalogue.LineItems/billable exactly (base included in exactly one place). ManageBillingButton opens the hosted portal. Paddle token and env are baked into the build, never fetched. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>