perf: reduce presence update frequency and fix background tab throttling (#13726)

## Description
Reduces the frequency of update_presence WebSocket calls from the live
chat widget and fixes agents appearing offline when the dashboard is in
a background tab.

## Fixes # (issue)
https://github.com/chatwoot/chatwoot/issues/13720

## Type of change

- [ ] Bug fix (non-breaking change which fixes an issue)


## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

app/javascript/widget/helpers/actionCable.js

@@ -13,9 +13,11 @@ const isMessageInActiveConversation = (getters, message) => {
   return activeConversationId && conversationId !== activeConversationId;
 };
 
+const WIDGET_PRESENCE_INTERVAL = 60000;
+
 class ActionCableConnector extends BaseActionCableConnector {
   constructor(app, pubsubToken) {
-    super(app, pubsubToken);
+    super(app, pubsubToken, '', WIDGET_PRESENCE_INTERVAL);
     this.events = {
       'message.created': this.onMessageCreated,
       'message.updated': this.onMessageUpdated,