Meta webhook → /api/whatsapp/webhook
→ /api/whatsapp/process-message (INTERNAL_WEBHOOK_SECRET)
→ lib/chatbot/flow-engine.ts
→ lib/whatsapp/api.ts (Graph API v25)
→ Convex runtime store (conversations, messages)Firestore repositories are being replaced by Convex; the active hot path uses runtimeStore and Convex mutations.