fix(whatsapp): prevent merged lid conversations from returning

server/test/whatsapp-identity.test.js

@@ -3,6 +3,7 @@ import test from 'node:test'
 import {
   canonicalWhatsAppJid,
   isWeakWhatsAppDisplayName,
+  resolvedWhatsAppJid,
   reusableWhatsAppConversations,
   whatsappCustomerStableId,
 } from '../src/whatsapp-identity.js'
@@ -16,6 +17,14 @@ test('WhatsApp LID resolves to the same canonical phone identity', () => {
   assert.equal(canonicalWhatsAppJid('987654321@lid', { canonicalJid: '15551234567:0@s.whatsapp.net' }), phoneJid)
 })
 
+test('a newly resolved phone identity overrides a stale cached LID', () => {
+  const lid = '987654321@lid'
+  const phoneJid = '15551234567@s.whatsapp.net'
+  assert.equal(resolvedWhatsAppJid(lid, {}, lid), lid)
+  assert.equal(resolvedWhatsAppJid(lid, { phone: '+1 555 123 4567' }, lid), phoneJid)
+  assert.equal(resolvedWhatsAppJid(lid, {}, phoneJid), phoneJid)
+})
+
 test('WhatsApp customer id remains stable after gateway reauthorization', () => {
   assert.equal(
     whatsappCustomerStableId('15551234567@s.whatsapp.net'),