fix: sentry issues (#10695)

1. Ensure audio player ref is accessible before triggering calls
([Sentry](https://chatwoot-p3.sentry.io/issues/6221981610))
2. Use correct default for attachments, this was incorrectly set to
`null` in a previous PR
([Sentry](https://chatwoot-p3.sentry.io/issues/5966738120))
3. Fix `lastNonActivityMessage` is not present
([Sentry](https://chatwoot-p3.sentry.io/issues/6116038455))
4. Fix `Alt+J` & `Alt+K` shortcuts not working
([Sentry](https://chatwoot-p3.sentry.io/issues/6075125384))

---------

Co-authored-by: Sivin Varghese <64252451+iamsivin@users.noreply.github.com>

app/javascript/dashboard/composables/chatlist/useChatListKeyboardEvents.js

@@ -1,6 +1,6 @@
 import { useKeyboardEvents } from 'dashboard/composables/useKeyboardEvents';
 
-export function useChatListKeyboardEvents({ listRef }) {
+export function useChatListKeyboardEvents(listRef) {
   const getKeyboardListenerParams = () => {
     const allConversations = listRef.value.querySelectorAll(
       'div.conversations-list div.conversation'
@@ -19,6 +19,7 @@ export function useChatListKeyboardEvents({ listRef }) {
       lastConversationIndex,
     };
   };
+
   const handleConversationNavigation = direction => {
     const { allConversations, activeConversationIndex, lastConversationIndex } =
       getKeyboardListenerParams();