I would like a solid, production-ready integration of the WhatsApp Meta Cloud API that I can plug straight into my existing stack. The single integration must power customer support chats, marketing broadcasts, and automated transactional notifications from several WhatsApp numbers—so switching senders on the fly has to be seamless. Core capabilities I need working from day one: • Full two-way messaging so agents or bots can read and reply in real time. • Sending and receiving multimedia (images, audio, video, documents) with correct MIME handling. • A reliable webhook pipeline that captures every event—message status, delivery receipts, user replies—and pushes them to my backend with proper retry logic. Please wire everything to run through multiple cloud-hosted numbers under the same Meta account, expose clear REST or GraphQL endpoints for my developers, and document the onboarding flow for adding more numbers later. Test coverage or a simple Postman collection confirming happy-path and error cases will be the acceptance gate.