feat: send ticket receipts via WhatsApp and normalize phone numbers

Add WhatsApp API integration for automated receipt delivery
Enforce country codes for all phone number inputs (defaults to +60)

server/utils/users.ts

@@ -44,7 +44,7 @@ export function parseCreateUserInput(body: {
     'Username must be 3 to 32 characters using lowercase letters, numbers, dot, dash, or underscore'
   )
   assertBadRequest(hasValidFullName(fullName), 'Full name must be at least 2 characters')
-  assertBadRequest(isValidPhoneNumber(phoneNumber), 'Phone number must contain 8 to 15 digits')
+  assertBadRequest(isValidPhoneNumber(phoneNumber), 'Phone number must include a country code, e.g. +60123456789')
 
   return {
     username,
@@ -64,7 +64,7 @@ export function parseUserProfileInput(body: {
   const role = body.role
 
   assertBadRequest(hasValidFullName(fullName), 'Display name must be at least 2 characters')
-  assertBadRequest(isValidPhoneNumber(phoneNumber), 'Phone number must contain 8 to 15 digits')
+  assertBadRequest(isValidPhoneNumber(phoneNumber), 'Phone number must include a country code, e.g. +60123456789')
   assertBadRequest(isUserRole(role), 'Role is invalid')
 
   return {