feat: Refetch the latest messages on action cable reconnect in widget (#6996)

app/javascript/widget/store/modules/conversation/mutations.js

@@ -62,6 +62,10 @@ export const mutations = {
     payload.map(message => Vue.set($state.conversations, message.id, message));
   },
 
+  setMissingMessagesInConversation($state, payload) {
+    Vue.set($state, 'conversation', payload);
+  },
+
   updateMessage($state, { id, content_attributes }) {
     $state.conversations[id] = {
       ...$state.conversations[id],
@@ -94,4 +98,12 @@ export const mutations = {
   setMetaUserLastSeenAt($state, lastSeen) {
     $state.meta.userLastSeenAt = lastSeen;
   },
+
+  setLastMessageId($state) {
+    const { conversations } = $state;
+    const lastMessage = Object.values(conversations).pop();
+    if (!lastMessage) return;
+    const { id } = lastMessage;
+    $state.lastMessageId = id;
+  },
 };