integration-builder

Composes a full vertical payment integration from canonical templates. Called by integration-specialist subagent after the user selects a provider. Loads templates by (provider, stack, ORM, deploy target, billing_mode, frontend_style, use_cases) and emits a coherent file plan that gets written to the user's project. Always cites webhook-verifier and SECURITY_RULES. Phase 1 supports stripe, mercadopago, wompi, lemonsqueezy on Next.js App Router and Express; Phase 2 adds more.