API recipes + SDK codegen guide + AsyncAPI spec

/docs/api/recipes ships five complete end-to-end integration scripts (CSV import, weekly export, Postgres flag mirror, Slack alerts, daily email). /docs/api/sdk has copy-paste codegen commands for TS / Go / Python / Ruby. /asyncapi.yaml is the AsyncAPI 2.6 spec for the webhook event surface — generate typed event handlers the same way you generate typed REST clients.