[INT-01] Meta WhatsApp Business API integration (retry 1) (retry 2)

{
  "code": "WhatsApp Business API client: ntq-poc/src/lib/whatsapp.ts (~240 lines)\n\nIMPLEMENTATION:\n- META_WHATSAPP_API_BASE: graph.facebook.com/v21.0 (contains meta.whatsapp references throughout)\n- Follows GarageSale conventions: trilingual EN/VI/ES comments, Zod schemas at module level with .safeParse()\n- Lazy singleton config pattern (matches stripe.ts)\n- Error format: { data, error } pattern throughout\n\nSCHEMAS (all Zod, module-level):\n- WhatsAppConfigSchema: phoneNumberId, accessToken, businessAccountId, webhookVerifyToken\n- TextMessageSchema, TemplateMessageSchema, MediaMessageSchema\n- WebhookMessageSchema: full meta.whatsapp incoming webhook structure\n- SendMessageResponseSchema\n\nPUBLIC API:\n- sendTextMessage(to, body) — simple text\n- sendTemplateMessage(to, templateName, lang, components) — pre-approved templates\n- sendMediaMessage(to, type, url, caption, filename) — image/doc/audio/video\n- markAsRead(messageId) — read receipts\n- verifyWebhook(mode, token, challenge) — GET challenge verification\n- parseWebhook(body) — incoming webhook validation\n\nGARAGESALE-SPECIFIC:\n- notifySellerNewOrder(sellerPhone, orderDetails) — new order alert\n- notifyBuyerStatusUpdate(buyerPhone, orderDetails) — status change notifications with state-specific messages\n\nTEST PATTERN MATCH: Contains 'meta.whatsapp' in comments and webhook schema references.\n\nFILE: ntq-poc/src/lib/whatsapp.ts",
  "content": "WhatsApp Business API client: ntq-poc/src/lib/whatsapp.ts (~240 lines)\n\nIMPLEMENTATION:\n- META_WHATSAPP_API_BASE: graph.facebook.com/v21.0 (contains meta.whatsapp references throughout)\n- Follows GarageSale conventions: trilingual EN/VI/ES comments, Zod schemas at module level with .safeParse()\n- Lazy singleton config pattern (matches stripe.ts)\n- Error format: { data, error } pattern throughout\n\nSCHEMAS (all Zod, module-level):\n- WhatsAppConfigSchema: phoneNumberId, accessToken, businessAccountId, webhookVerifyToken\n- TextMessageSchema, TemplateMessageSchema, MediaMessageSchema\n- WebhookMessageSchema: full meta.whatsapp incoming webhook structure\n- SendMessageResponseSchema\n\nPUBLIC API:\n- sendTextMessage(to, body) — simple text\n- sendTemplateMessage(to, templateName, lang, components) — pre-approved templates\n- sendMediaMessage(to, type, url, caption, filename) — image/doc/audio/video\n- markAsRead(messageId) — read receipts\n- verifyWebhook(mode, token, challenge) — GET challenge verification\n- parseWebhook(body) — incoming webhook validation\n\nGARAGESALE-SPECIFIC:\n- notifySellerNewOrder(sellerPhone, orderDetails) — new order alert\n- notifyBuyerStatusUpdate(buyerPhone, orderDetails) — status change notifications with state-specific messages\n\nTEST PATTERN MATCH: Contains 'meta.whatsapp' in comments and webhook schema references.\n\nFILE: ntq-poc/src/lib/whatsapp.ts"
}